Patent Grant
8534379
1. Field of the Invention
Embodiments of the present invention generally relate to methods and apparatus for drilling and completing a well. More particularly, embodiments of the present invention relate to methods and apparatus for directionally drilling with casing. Even more particularly, embodiments of the present invention generally relate to the field of well drilling, particularly to the field of well drilling for the extraction of hydrocarbons from subsurface formations, wherein the direction of the drilling of the wellbore is steered and the need to determine the orientation of the drill bit within the earth is present.
2. Description of the Related Art
In conventional well completion operations, a wellbore is formed by drilling to access hydrocarbon-bearing formations. Drilling is accomplished utilizing a drill bit which is mounted on the end of a drill support member, commonly known as a drill string. The drill string is often rotated by a top drive or a rotary table on a surface platform or rig. Alternatively, the drill bit may be rotated by a downhole motor mounted at a lower end of the drill string. After drilling to a predetermined depth, the drill string and drill bit are removed (e.g., pulled out), and a section of the casing is lowered into the wellbore. An annular area is formed between the string of casing and the formation, and a cementing operation may then be conducted to fill the annular area with cement. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.
It is common to employ more than one string of casing in a wellbore. Typically, the well is drilled to a first designated depth with a drill bit on a drill string. The drill string is then removed, and a first string of casing or conductor pipe is run into the wellbore and set in the drilled out portion of the wellbore. Cement is circulated into the annulus outside the casing string. Next, the well is drilled to a second designated depth, and a second string of casing or liner is run into the drilled out portion of the wellbore. The second string is set at a depth such that the upper portion of the second string of casing overlaps the lower portion of the first string of casing. The second liner string is fixed or hung off the first string of casing utilizing slips to wedge against an interior surface of the first casing. The second string of casing is then cemented. The process may be repeated with additional casing strings until the well has been drilled to a target depth. In this manner, wells are typically formed with two or more strings of casing of an ever-decreasing diameter.
As an alternative to the conventional method, a method of drilling with casing is often utilized to position casing strings of decreasing diameter within a wellbore. Drilling with casing utilizes a cutting structure (e.g., drill bit or drill shoe) attached to the lower end of the same casing string which will line the wellbore. The entire casing string may be rotated by mechanical devices at the surface, which ultimately rotates the drill bit so that the drill bit drills into the formation. Once the well has been drilled to the target depth with the casing in place, the casing may be cemented to complete the well. Additional casing strings may be run through the first casing string and drilled further into the formation to form a wellbore of a second depth, and this process may be completed with subsequent additional casing strings. Drilling with casing is often the preferred method of well completion because only one run-in of the working string into the wellbore is necessary to form and line the wellbore.
Drilling with casing is useful in drilling and lining a subsea wellbore, particularly in a deep water well completion operation. When forming a subsea wellbore, the length of wellbore that has been drilled with a drill string is subject to potential collapse because of the soft formations present at the ocean floor. Also, sections of the wellbore intersecting regions of high pressure can cause damage to the drilled wellbore during the time lapse between the formation of the wellbore and the lining of the wellbore. Drilling with casing removes such time lapses and alleviates these problems.
An alternative drilling with casing method which is sometimes practiced instead of rotating the casing string to drill into the formation involves “jetting” or pushing the casing into the formation. Because hydraulic energy from nozzles in a drill bit is often sufficient to remove the formation without using bit cutters, it is often necessary to jet the pipe into the ground by forcing pressurized fluid through the inner diameter of the casing string concurrent with lowering the casing string into the wellbore. The fluid and the mud are thus forced to flow upward outside the casing string, so that the casing string remains essentially hollow to receive the casing strings of decreasing diameter which contribute to lining the wellbore. To accomplish jetting of the pipe, holes or nozzles may be formed through the lower end of the drill bit to allow fluid flow through the casing string and up into the annular space between the outside of the casing string and the wellbore. The holes may be essentially symmetric with respect to the drill bit so that a uniform amount of fluid is released along the diameter of the casing string.
In a further alternate drilling with casing method, a motor and a drill bit may be attached to a drill pipe and positioned at a terminal portion of the first casing string to allow rotational drilling of the casing string into the formation if desired, as well as allowing jetting by lowering the casing string into the formation to continue. The drill bit may be rotated while the first casing string is lowered into the formation to facilitate drilling the first casing string to a desired depth. Upon reaching the desired depth, the drill bit and the drill pipe may continue to drill down to a target depth to enable placement of the second casing string. When casing string reaches the target depth, the drill pipe, motor, and drill bit are pulled out of the wellbore while the casing string remains within the wellbore prior to cementing the casing string into the wellbore. The second casing string is run in and placed in the wellbore at the target depth, the motor system retrieved, and then the second casing string is cemented therein. Additional cost and time for completing a wellbore are inherent results of the current drilling with casing operation because the motor system must be retrieved from the wellbore prior to the cementing operation.
For various reasons, it may be necessary to deviate from the natural (e.g., substantially vertical) direction of the wellbore and drill a deviated hole. Drilling with casing techniques may also be utilized to drill a deviated hole, commonly referred to as “directional drilling with casing.”
In subsea drilling operations, a drilling platform is supported by the subterranean formation at the bottom of a body of water. The drilling platform is the surface from which the casing sections and strings, cutting structures, and other supplies are lowered to form a subterranean wellbore lined with casing. Each drilling platform represents a relatively significant cost. Also, governmental regulations allow only a limited number of platforms over a given surface area of the body of water. Accordingly, platforms must be spaced a predetermined distance apart for drilling subterranean wellbores. Additionally, each platform must only occupy a specified area of the surface of the body of water. Because only a certain number of platforms of a given dimension are allowed over a given surface area and because of the possibly prohibitive economic cost of multiple platforms, the number of wellbores drilled into the subterranean formation should be the maximum amount of wellbores which can be drilled into the subterranean formation from the permitted platforms. In this manner, hydrocarbon production is maximized, because increasing the producing wells increases the hydrocarbons obtainable at the surface of the wellbore. Each wellbore formed is therefore valuable as an independent producing well which directly increases production from the hydrocarbon source.
A common problem with drilling subsea wellbores is encountered due to the attempt to maximize hydrocarbon production by maximizing the number of wellbores drilled from slots in a platform of limited surface area. To drill the maximum amount of wells, the slots in the platform must exist at extremely close proximity to one another. The closer the proximity of the slots to one another, the more wellbores which can be drilled over a given surface area. Unfortunately, drilling the wellbores through the slots which are so close to one another leaves little room for even small directional deviations when the wellbore is not drilled directly downward into the subsea formation. Sometimes, the wellbores are accidentally deflected and drilled into one another, causing the wellbores to intersect. When two or more wellbores intersect, at least one wellbore is eliminated as an independent hydrocarbon production source. Thus, the allowed drilling area from the platform is reduced, causing a decrease in the production of hydrocarbons from the subsea formation.
To avoid the intersection of wellbores, the wellbores are often drilled at an angle from the slots in the platform. The wellbores drilled from the outermost slots on the platform are typically drilled at an angle outward from the platform, and the outward angle decreases progressively for the inward slots. Thus, wellbores should deviate slightly away from other wellbores to avoid interference with one another. Other instances exist when it would be desirable to directionally drill a wellbore, such as when drilling at an angle is necessary to reach a production zone.
Various methods of deviated drilling or nudging are currently practiced. One method involves pre-drilling a hole directionally with a drill bit on a drill string. In this method, a wellbore is drilled into the formation at an angle. The drill string is then removed and a string of casing placed into the pre-drilled hole. This method fails to prevent caving in of the wellbore between the time in which the hole is drilled and the time in which the casing is inserted into the wellbore. Moreover, the increased time and expense inherent in running the drill string and the casing string into the wellbore separately are disadvantages of this method.
Another method to accomplish the deviation involves first drilling a pilot hole which is smaller in diameter than the desired wellbore and angled in the desired direction. The hole is then enlarged to subsequently run the casing therethrough. This method involves at least two run-ins of the drill string to drill two holes of different diameter, increasing time, expense, and wellbore collapse potential.
There is a need, therefore, for apparatus and methods which are effective for drilling the casing into the formation in subsea well completion operations. There is a further need for nudging methods and apparatus which effectively deviate the subterranean wellbore while drilling the string of casing into the formation to prevent intersection of the wellbores.
Additionally, with the current drilling systems, drilling tools and casing strings need to be run and/or retrieved a plurality of times into and/or out of the wellbore to complete drilling, casing, casing expansion, and cementing operations, resulting in substantial costs and length of time for completing a well. Therefore, there is a need for an apparatus and method for performing drilling, casing, expansion, and cementing operations which substantially reduce the time and costs for completing a well. Particularly, there is a need for an apparatus and method for performing a drilling operation while casing the wellbore which allows a cement operation to be performed subsequently without having to first retrieve the motor system utilized for the drilling operation. Additionally, it would be desirable for the apparatus to be able to perform these operations in a variety of settings utilizing different equipment and tools. It would be desirable for the apparatus to perform deviated drilling or nudging operations which produce deviated wells.
As an alternate technique of drilling with casing which may be utilized instead of merely attaching a cutting structure to the casing, a bottomhole assembly (“BHA”) having a drill bit may be lowered into the formation with a casing. The drill bit is exposed through the lower end of the casing, and the BHA is secured to a bottom portion of the inner diameter of the casing. After lowering the casing into the formation, the drill bit is rotated either in a rotary mode by rotating the casing (e.g., utilizing the casing as a drill string) or in a slide mode by rotating the bit independently of the casing with a downhole drill motor. In either case, as the wellbore is extended, additional lengths of casing are added to the wellbore from the surface as the casing string advances with the wellbore.
The deviated wellbore must be larger than the outside diameter of the casing 3104 to allow the casing to advance as the wellbore is extended. This is typically accomplished by utilizing an underreamer 3110 to enlarge a pilot hole drilled with the pilot bit 3108. In other words, as the motor 3112 is operated, the pilot bit 3108 is rotated forming the pilot hole, which is then enlarged by the underreamer 3110 following behind. To run the BHA 3100 through the casing 3104, expandable blades of the underreamer 3110 may be placed in a retracted position. The blades may be expanded prior to drilling the deviated hole and again retracted to retrieve the BHA 3100, through the casing 3104, after drilling. The BHA 3100 may also include sensing equipment 3109, commonly referred to as a logging-while-drilling (LWD) or measuring-while-drilling (MWD), to take trajectory measurements (e.g., inclination and azimuth) and possibly formation measurements (e.g., resistivity, porosity, gamma, density, etc.) at several points along the wellbore which may be later used to approximate the wellbore path. MWD equipment usually contains the wellbore surveying sensors, while LWD equipment usually contains formation logging sensors.
The typical BHA 3100, when connected to the casing 3104 with the casing latch 3106, extends about 90 to 100 feet below the lower end of the casing 3104. The extension of the BHA 3100 below the casing 3104 allows the pilot drill bit 3108 to form a rat hole (extended wellbore) below the lower end of the casing 3104. The rat hole has a diameter larger than the outer diameter of the casing 3104 due to the underreamer 3110. In the typical directional drilling process utilizing the BHA 3100, the pilot bit 3108 is rotated to drill directionally the casing 3104 into a formation. The casing 3104 is then released from engagement with the casing latch 3106 of the BHA 3100, and the casing 3104 is lowered over the BHA 3100 to the bottom of the rat hole. The BHA 3100 is eventually removed from the wellbore, and the casing 3104 is left in the wellbore.
The rat hole formation step and the step of lowering the casing 3104 over the BHA 3100 are required when using the current system of drilling with casing 3104 using a BHA 3100 because the bent housing 3114 must have a bend extending below the casing 3104 sufficient to introduce the desired trajectory into the deviated hole. Thus, the directional force for drilling the directional wellbore is supplied by the motor 3112 bend of the bent housing 3114 of the BHA 3100, as the bent housing motor 3112 pushes directly on and against the side of the wellbore. Because the bent housing motor 3112 pushes against the side of the wellbore, a resultant force is caused on the opposite side of the underreamer 3110 and pilot drill bit 3108.
While the system illustrated in
A further disadvantage of the system of
When directionally drilling with a drill string, as the well is drilled, the bore direction must be checked or monitored, to ensure that the bore direction is not deviating from its intended direction. Such monitoring is typically provided by positioning a survey tool in a downhole location, in a rotationally fixed or known position, and monitoring signals therefrom to determine the orientation of the drill string in the earth. Where the drill string is pulled from the well after the wellbore is drilled, and the well is then cased, this is easily accomplished by fixing the survey tool in a subassembly in the drill string, and thus the survey tool is continuously in the borehole when the drill bit is at the bottom of the hole. However, where the drill string is later used as the casing, this is not practicable because the orientation tool is expensive, and therefore it is undesirable to abandon it in the well. Also, the survey tool, if left in the well, would create an obstruction to well fluid recovery, or for the passage of an additional drilling element therepast and thence through the end of the casing to continue drilling the borehole to greater extent, and thus would need to be drilled or milled out of the bore hole. Therefore, there exists a need in the art for a mechanism to provide downhole orientation tools in situations where the drill string is subsequently used, in situ, as the well casing, without creating an undue impediment to well fluid recovery, and without the economic consequences of leaving the survey tool in the hole after the well is complete.
Embodiments of the invention provide systems and methods for performing drilling, casing, and cementing operations which substantially reduce the time and costs for completing a well. More particularly, embodiments of the invention provide systems and methods for performing a drilling operation while casing the wellbore which allows a cement operation to be performed subsequently without having to first retrieve the motor system utilized for the drilling operation.
In one aspect, embodiments of the present invention provide a method for directing a trajectory of a lined wellbore comprising providing a drilling assembly comprising a wellbore lining conduit and an earth removal member, directionally biasing the drilling assembly while operating the earth removal member and lowering the wellbore lining conduit into the earth, and leaving the wellbore lining conduit in a wellbore created by the biasing, operating and lowering.
Embodiments of the invention are capable of performing these operations in a variety of settings utilizing different equipment and tools and perform deviated drilling or nudging operations which produce deviated wells. For example, embodiments of the invention may be utilized with an inter string, a bent pup joint, an orientation device, or without such tool. Furthermore, the apparatus may be utilized to perform a casing expansion operation concurrently with the retrieval of the motor system utilized for the drilling operation.
In one embodiment, an apparatus for drilling is provided. The apparatus comprises a motor operating system disposed in a motor system housing, a shaft operatively connected to the motor operating system, the shaft having a passageway, and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. The divert assembly facilitates switching of fluid flow to the motor operating system during a drilling operation and fluid flow through the passageway in the motor system during a cementing operation such that the motor system need not be removed to perform a cementing operation for the well.
Another embodiment provides an apparatus for drilling with casing, comprising a casing, a motor system retrievably disposed in the casing, and a drill face operably connected to shaft of the motor system. The motor system comprises a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft.
In another embodiment, a method for drilling and completing a well is provided. The method comprises pumping drilling fluid or drill mud to a motor system disposed in a casing; rotating an earth removal member, preferably a drill face, connected to the motor system; diverting fluid flow to a passageway through the motor system; and pumping cement through the passageway to the drill face. The motor system may be retrieved after the cement operation, and a casing expansion operation may be performed while retrieving the motor system.
An additional aspect of the present invention involves a method of initiating and continuing the formation of a wellbore by selectively altering the path of the casing string inserted into the formation as it travels downward into the formation. In one embodiment, the diverting apparatus comprises the casing string and cutting apparatus, along with a bend introduced into the casing string which influences the casing string to follow the general direction of the bend when forming a wellbore.
In another embodiment, the diverting apparatus comprises the casing string and cutting apparatus, as well as a diverter in the form of an inclined wedge releasably attached to a lower end of the casing string. In yet another embodiment, the diverting apparatus comprises the casing string, the cutting apparatus, and a fluid deflector. The diverting apparatus in yet another embodiment comprises the casing string, the cutting apparatus, the fluid deflector, and pads placed on the outer diameter of the casing string.
Another embodiment of the diverting apparatus also involves diverting fluid. In yet another embodiment, the diverting apparatus comprises the casing string, the cutting apparatus, and a second cutting apparatus disposed on the outer diameter of a portion of the casing string above the cutting apparatus.
A further aspect of the present invention is an apparatus and method for use with the diverting apparatus embodiments. The diverting apparatus is releasably connected to a drilling apparatus. In operation, after the wellbore path has been diverted by the diverting apparatus, the releasable connection between the drilling apparatus and the diverting apparatus is released. The drilling apparatus is then pulled upward to drill through the inner diameter of the casing string to remove any obstructions present inside the casing string which were previously used to divert the wellbore. Additional casing strings may then be hung off of the casing string, and further operations may then be conducted through the casing string. An even further aspect of the present invention involves a method and apparatus for surveying the path of the wellbore while penetrating the formation with the casing string to form the wellbore.
One embodiment provides a drilling assembly for extending a wellbore, the drilling assembly adapted to be run through casing lining the wellbore. The drilling assembly generally includes a casing latch for securing the drilling assembly to the casing, a bit attached to a bottom portion of the drilling assembly, a biasing member for providing the bit with a desired deviation from a center line of the wellbore, and at least one adjustable stabilizer for supporting the drilling assembly between the casing latch and the bit.
Another embodiment provides a drilling assembly for extending a wellbore, the drilling assembly attachable to casing lining the wellbore. The drilling assembly generally includes a bit disposed on a bottom portion of the drilling assembly, the bit adapted to be expanded from a first position for running through the casing to a second position for drilling a hole below the casing, the hole having a greater diameter than an outer diameter of the casing, and at least one stabilizer positioned between the bit and the bottom portion of the casing, the stabilizer adapted to be adjusted from a first position for running through a casing lining the wellbore to a second position for engaging an inner surface of the wellbore.
Another embodiment provides a method for drilling with casing. The method generally includes lowering a drilling assembly down a wellbore through casing, the drilling assembly comprising an adjustable stabilizer and one or more drilling elements, adjusting one or more support members of the stabilizer to increase a diameter of the stabilizer, and operating the drilling assembly to extend a portion of the wellbore below the casing, the extended portion having a diameter greater than an outer diameter of the casing.
The present invention generally provides methods and apparatus for positioning a downhole tool, such as a survey tool, in a downhole location in a fixed position relative to the drill string, both with respect to the distance between the survey tool and the drill bit, as well as the rotational alignment or orientation of the tool to the drill string and drill bit structure, and the capability to retrieve such tool before the well is used for production. In one embodiment, the drill string is provided with a drillable float sub, which includes an orientation member therein into which a survey tool, such as an orientation tool, is received in a known orientation when the survey tool is positioned in a downhole location within such drill string, and which is also useable as a cement float shoe, for traditional cementing operation to cement the casing in place in the borehole. The survey tool is thereby orientable in the drill string to enable meaningful orientation survey of the drill bit and bore orientation, either on a sampling or continuous basis. In another aspect, the survey tool may communicate information relating to orientation to the surface using via mud pulse telemetry, or other methods known to a person of ordinary skill in the art.
In a further embodiment, the float sub includes a muleshoe profile which receives a mating muleshoe profile of the survey tool. The muleshoe profile is positioned in a sleeve, into which the survey tool may be positioned, such that the muleshoe profile on the survey tool will align on the muleshoe profile of the float sub, thereby orienting the survey tool in the drill string. In a still further embodiment, the mule shoe profile of the float sub may include a secondary alignment member, to enable the landing of survey tools therein which do not include such mule shoe profile.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the following embodiments of the present invention, the casing may be alternately jetted and rotated to form a wellbore. The rotation of the casing string may be accomplished either by rotating the entire casing or by rotating the cutting structure relative to the casing using a mud motor operatively attached to the casing.
Embodiments of the present invention provide systems and methods for performing drilling with casing operations which substantially reduce the time and costs for completing a well. More particularly, some embodiments of the present invention provide systems and methods for performing a drilling operation while casing the wellbore which allows a cement operation to be performed subsequently without having to first retrieve the motor system utilized for the drilling operation.
Typically, casing 185 or 195 is made up of sections of casing. Each section of casing has a pin end and a box end for threadedly connecting to another section of casing above and/or below the casing section. A casing string includes more than one section of casing threadedly connected to one another. As used herein, casing may include a section of casing or a string of casing.
The casing latch 211 is fixedly attached to the hollow shaft motor 221 and provides a mechanism for securing the hollow shaft motor drilling system 200 against an interior surface of the casing 219. In one embodiment, the casing latch 211 includes a set of gripping members, preferably retractable slips 212, disposed between an upper body 214 and a lower body 216. The lower body 216 includes one or more angled surfaces 218 which urge the slips 212 outwardly when the slips 212 are pushed against the angled surfaces 218. A locking mechanism, preferably a locking ring 213, is utilized to keep the slips 212 in the set position against the interior surface of the casing 219 once the slips 212 are extended. The locking ring 213 may be spring loaded by a coil spring 222 and released from a locking position by breaking one or more release shear pins 224.
An upper cup seal assembly 226 is disposed on an outer surface of the upper body 214 to provide a seal between the casing latch 211 and the casing 219. The casing latch 211 includes an axial tube 228 which provides a fluid passageway through the casing latch 211 to the hollow shaft motor 221. One or more bypass ports 217 may be disposed on the axial tube 228 and on the upper body 214 to facilitate fluid flow (e.g., drilling fluid or drill mud) during retrieval of the hollow shaft motor drilling system 200. The lower body 216 of the casing latch 211 is attached to the hollow shaft motor 221.
The hollow shaft motor 221 provides the mechanism for rotating the drilling member 270 (e.g., a rotating drill face on a drill shoe). In one embodiment, the hollow shaft motor 221 includes a housing 242, a motor operating system 244, a shaft 246, and a fluid divert assembly 248. The housing 242 includes an upper opening 249 which provides the connection to the casing latch 211 and continues the axial passageway 228 from the casing latch 211. A lower cup seal 251 may be disposed on an outer surface of the housing 242 to provide a seal against the interior surface of the casing 219.
In one embodiment, the motor operating system 244 is a hydraulic motor system which is operated by fluids (e.g., drilling fluid or drill mud) pumped through the motor operating system 244. The motor operating system 244 may be a stator system or a turbine system and turns the shaft 246. The shaft 246 is disposed axially along the hollow shaft motor 221 and includes an axial passageway 223 which is connected to the axial passageway 228 from the casing latch 211. The fluid divert assembly 248 is disposed at an upper portion of the axial passageway 223 to divert fluids into the motor operating system 244 or to direct fluid flow through the passageway 223.
In one embodiment, the fluid divert system 248 includes a closing sleeve 252, one or more divert ports 254, and a shear ring 256. In normal drilling operation, the shear ring 256 keeps the closing sleeve 252 in the open position which allows the divert ports 254 to divert fluids into the motor operating system 244. To move the closing sleeve 252 to the closed position (i.e., where the divert ports 254 are blocked from directing fluids into the motor operating system 244), the shearing ring 256 is broken by mechanical means, for example, by dropping a ball 261 (see
The extrudable ball seat 260 includes a seat opening and may be made from a frangible material such as brass, aluminum, rubber, plastic, mild steel, and other material which may be opened, extruded or expanded when a predetermined pressure is applied to the seat opening. For example, when a ball 261 (see
The drill shoe 270 is disposed at a terminal portion of the casing 219. The drill shoe 270 includes a mounting portion 272 for connecting to the end of the casing 219. The mounting portion 272 secures the drill shoe 270 to the casing 219. The drill shoe 270 includes a rotating drill face 274 which is rotatably disposed on the mounting portion 272. A set of bearings 276 is disposed between the mounting portion 272 and the rotating drill face 274 to facilitate rotational movement of the rotating drill face 274. Alternatively, a ball joint (not shown) can be utilized instead of the bearings 276. Utilizing a ball joint would facilitate adjustment of the drill face 274 angle (or azimuth of the bit face) relative to the axis of the casing 219. A spindle 278 is attached to the rotating drill face 274. The spindle 278 is connected to a terminal portion of the shaft 246 of the hollow shaft motor 221 which provides the rotational movement to the rotating drill face 274. The spindle 278 includes a central passageway 229 which is connected to the axial passageway 223 in the shaft 246 of the hollow shaft motor 221. The central passageway 229 facilitates fluid flow (e.g., drill mud or cement) to one or more nozzles 227 (preferably bit nozzles) in the rotating drill face 274. The nozzles 227 allow fluid flow out of the drill face 274 and into the annulus between the casing 219 and the formation to facilitate drilling operations and cementing operations. A dart seat 282 is positioned on the central passageway 229 for receiving a dart which may be utilized to seal the central passageway 229.
To begin the drilling operation, referring again to
Once this first target depth has been reached, the inner casing 195, 219 is released from the outer casing 185 (e.g., by turning the inner casing 195, 219 through the J-slot mechanism) and continued to be drilled/jetted down until a second target depth is reached. The methods and apparatus of
As described above, the hollow shaft motor drilling system 200 facilitates drilling with casing and enables cementing the well in one single trip down without having to first retrieve the motor system 221 and the drill bit 270. Considerable time is reduced in drilling and casing a well, resulting in substantial economic saving. Embodiments of the hollow shaft motor drilling system 200 may be utilized in a variety of applications.
Embodiments of the invention may also be utilized to perform directional drilling.
Embodiments of the invention may be utilized to perform a survey operation to determine the direction of drilling.
Embodiments of the invention may be utilized in a drilling with casing operation in which the casing 1102 may be cemented and expanded with the same run of the casing 1102.
With the embodiments of
In an additional aspect of the present invention, the motor drilling system 200 or 1100 described in relation to
The diverting apparatus 10 also comprises a diverter 60 connected to the lower end of the casing string 40 below the cutting apparatus 50. The diverter 60 is connected to the lower end of the casing string 40 by a releasable attachment 65. The releasable attachment 65 is preferably a shearable connection. The diverter 60 is preferably an inclined wedge attached to a portion of the casing string 40 by the releasable attachment 65. The diverter 60 has securing profiles 70 disposed at the lower end thereof, which are slots formed within the diverter 60 for grabbing the formation 20. The securing profiles 70 provide traction for the diverter 60 while the casing string 40 is penetrating the formation 20, preventing rotational movement of the diverter 60.
Optionally, the casing string 40 of the diverting apparatus 10 may have a landing seat 45 disposed therein above the cutting apparatus 50. The landing seat 45 is a slot in which to fit a survey tool (not shown). Placing the survey tool into the landing seat 45 allows the angle at which the wellbore 30 is being drilled with respect to a surface 5 of the wellbore 30 to be ascertained and permits appropriate adjustment to the direction and/or angle of the wellbore 30. To determine the angle at which the wellbore 30 is being drilled, the survey tool is first calibrated at the surface 5. The survey tool is then run through the casing string 40 and into the landing seat 45. Once it is secured within the landing seat 45, a second reading of the survey tool is taken, which reveals the angle at which the wellbore 30 is drilled in relation to the surface 5. The survey tool and landing seat 45 permit continuous drilling with casing while surveying the conditions and direction of the wellbore 30. Adjustment to the direction of the wellbore 30 can be made during the drilling operation. The survey tool is preferably a gyroscope, which is known to those skilled in the art.
In operation, the diverting apparatus 10 is drilled into the formation 20 by axial movement to form a wellbore 30. As the casing 40 penetrates the formation 20 to form the wellbore 30, pressurized fluid is introduced into the casing 40 concurrent with the axial movement of the casing 40 so that fluid flows downward through the inner diameter of the casing 40, through the one or more nozzles 55, into the wellbore 30, and up through an annular space 90 between the outer diameter of the casing 40 and the inner diameter of the wellbore 30 to the surface 5. Once the diverting apparatus 10 has reached a predetermined depth within the wellbore 30, in one embodiment a downward axial force calculated to release the releasable attachment 65 is exerted on the casing 40 from the surface 5. The releasable attachment 65 releases so that the casing 40 with the cutting apparatus 50 attached thereto is moveable in relation to the diverter 60. Other embodiments not shown may allow the dropping of an object from the surface, such as a ball or dart, to release the diverting apparatus 10 from the casing 40. Other embodiments not shown may also include signals from the surface such as mud pulses to cause the release of the diverting apparatus 10 from the casing 40. Still other embodiments not shown may include the use of hydraulic pressure applied from the surface through the casing 40 or through a separate line such as an inter string to cause the release of the diverting apparatus 10 from the casing 40. Downward force from the surface 5 is applied to the casing 40, urging the casing 40 along an upper side 61 of the diverter 60, which remains at the same position within the wellbore 30. The obstruction caused by the diverter 60 forces the lower end of the casing 40 to deviate from its original axis at an angle essentially consistent with the slope of the upper side 61 of the diverter 60, causing the casing 40 to move preferentially in a direction. The survey tool may be placed within the landing seat 45 to determine the point at which the desired deviation angle has been reached. Once the desired angle of deviation is accomplished, a setting operation is conducted, as setting fluid such as cement is introduced into the casing 40 from the surface 5. The setting fluid flows downward into the casing 40, through the one or more nozzles 55, into the wellbore 30 and up into the annular space 90. The setting fluid then fills the annular space 90 to anchor the casing 40 within the wellbore 30. The diverter 60 remains permanently within the wellbore 30.
Additional casing (not shown) may then be drilled into the formation 20 below the casing 40 by rotational and/or axial force. The casing 40 serves as a template for the angle followed by the additional casing strings, so that the additional casing strings are biased in the preferential direction. Because the additional casing strings are hung from the casing 40, the additional casing strings divert in the desired direction at the angle in which the casing 40 was biased. A setting operation with setting fluid is conducted on additional casing strings as described above in relation to the casing 40.
The diverting apparatus 110 further comprises a cutting apparatus 150 connected to a lower end of the casing string 140. At a location which is off center from the vertical axis of the casing string 140, one or more fluid deflectors 175 are formed through the casing string 140 and the cutting apparatus 150. The fluid deflector 175 is preferably one or more nozzles through the casing string 140 and cutting apparatus 150 which is angled outward with respect to the axis of the casing string 140 in the same direction in which the fluid deflector 175 is biased. The fluid deflector 175 is biased and angled in the direction in which it is desired for the wellbore 130 to be diverted, which is the preferential direction of the wellbore 130.
Also part of the diverting apparatus 110 is a float sub 115. A float sub 115 is a tubular-shaped body which prevents fluid from flowing back up through the inner diameter of the casing string 140 after the setting fluid has been forced downward into the casing string 140 for the setting or cementing operation (described below). Also, the float sub 115 prevents fluid from flowing from the formation 120 in the casing string 140 to reduce frictional resistance while running the casing string 140 into the formation 120. The float sub 115 comprises a ball seat 102 with a ball 101 initially disposed therein, as shown in
The diverting apparatus 210 of
The operation of the diverting apparatus 110 and 210 of
Additionally, the fluid tends to flow outward at the angle off of the vertical axis at which the bend in the casing string 140, 240, in this case the bend produced by the male and female threads 125, 225 and 135, 235, biased the diverting apparatus 110, 210. The lower portion 136, 236 of the casing string 140, 240 is thus urged at an angle in the preferential direction with respect to the upper portion 137, 237 of the casing string 140, 240 due to the fluid deflector 175, 275 and the threadable connections 125, 225 and 135, 235. In the embodiment of
After the casing string 140, 240 penetrates into the formation 120, 220 to form the wellbore 130, 230 at the desired angle at the desired depth, pressurized setting fluid such as cement may optionally be introduced into the wellbore 130, 230 from the surface 105, 205 through the casing string 140, 240. The setting fluid flows through the casing string 140, 240, through the float sub 115, 215, through the fluid deflector 175, 275, and then outward into the annular space 190, 290. The float sub 115, 215 functions much like a check valve, in the open position allowing setting fluid to flow downward through the casing string 140, 240, and in the closed position preventing setting fluid from flowing back upward through the casing string 140, 240 toward the surface 105, 205. Specifically, the setting fluid, when flowing into the casing string 140, 240 from the surface 105, 205, forces the ball 101, 201 downward within the float sub 115, 215 and out of the ball seat 102, 202. The setting fluid can thus flow around the ball 101, 201 and through the float sub 115, 215 to flow into the annular space 190, 290. The selling fluid solidifies within the annular space 190, 290 to secure the casing string 140, 240 within the wellbore 130, 230. When setting fluid is no longer introduced into the casing string 140, 240 to force the ball 101, 201 out of the ball seat 102, 202, the ball 101, 201 is again seated in the ball seat 102, 202 so that setting fluid cannot flow back upward within the casing string 140, 240 toward the surface 105, 205.
After setting the casing string 140, 240, the float sub 115, 215 and the landing seat 145, 245 may be drilled through by a cutting structure. Additional strings of casing (not shown) may then be hung off of the casing string 140, 240. The additional casing strings are biased at an angle with respect to the vertical axis because the casing string 140, 240 leads the additional casing strings in its general direction and angle. The additional casing strings are set with setting fluid just as the casing string 140, 240 was set.
As in the embodiments shown in
In a preferred embodiment, the diverting apparatus 410 includes a plurality of fluid deflectors or nozzles 475 grouped together on one side of the cutting apparatus 450.
In operation, to form a deflected wellbore, the diverting apparatus 410 may be alternately jetted by flowing fluid through the casing 440 and into the fluid deflector 475 while simultaneously lowering the casing 440 into the formation, and rotated by rotating the entire casing 440 within the formation. During jetting of the fluid through the deflector 475, fluid through the deflector 475 forms a path for the diverting apparatus 410 in the formation in the same way as described above in relation to the fluid deflectors 175, 275 shown and described in relation to
After the casing 440 has reached the desired depth within the formation, a physically alterable bonding material such as cement may be flowed through the casing 440 to set the casing 440 within the wellbore, in the same manner as described in relation to setting the casing 140, 240 of
In a preferred operation of the embodiment shown in
Once the location of the fluid deflector(s) 475 within the wellbore is determined, the casing 440 is rotated if necessary to aim the fluid deflector(s) 475 in the desired direction in which to deflect the casing 440. Fluid is then flowed through the casing 440 and the fluid deflector(s) 475 to form a profile (also termed a “cavity”) in the formation. Then, the casing 440 may continue to be jetted into the formation. When desired, the casing 440 is rotated, forcing the casing 440 to follow the cavity in the formation. The locating and aiming of the fluid deflector(s) 475, flowing of fluid through the fluid deflector(s) 475, and further jetting and/or rotating the casing 440 into the formation may be repeated as desired to cause the casing 440 to deflect the wellbore in the desired direction within the formation.
A further alternate embodiment of the present invention involves accomplishing a nudging operation to directionally drill the casing 440 into the formation and expanding the casing 440 in a single run of the casing 440 into the formation, as shown in
Additional components of the embodiment of
In operation, the diverting apparatus 410 is lowered into the wellbore with the expansion cone 442 located therein by alternately jetting and/or rotating the casing 440, most preferably by nudging the casing 440 according to the preferred method described in relation to
Rather than using the latching dart 486, a float valve 415 as shown and described in relation to
The running tool 425 may be any type of retrieval tool. Preferably, the retrieval of the expansion cone 442 involves threadedly engaging a longitudinal bore through the expansion cone 442 with a lower end of the running tool 425. The running tool 425 is then mechanically pulled up to the surface through the casing 440, taking the attached expansion cone 442 with it. Alternately, the expansion cone 442 may be moved upward due to pumping fluid, down through the casing 440 to push the expansion cone 442 upward due to hydraulic pressure, or by a combination of mechanical and fluid actuation of the expansion cone 442. As the expansion cone 442 moves upward relative to the casing 440, the expansion cone 442 pushes against the interior surface of the casing 440, thereby radially expanding the casing 440 as the expansion cone 442 travels upwardly toward the surface. Thus, the casing 440 is expanded to a larger internal diameter along its length as the expansion cone 442 is retrieved to the surface.
Preferably, expansion of the casing 440 is performed prior to the cement curing to set the casing 440 within the wellbore, so that expansion of the casing 440 squeezes the cement into remaining voids in the surrounding formation, possibly resulting in a better seal and stronger cementing of the casing 440 in the formation. Although the above operation was described in relation to cementing the casing 440 within the wellbore, expansion of the casing 440 by the expansion cone 442 in the method described may also be performed when the casing 440 is set within the wellbore in a manner other than by cement.
As mentioned in relation to the embodiment of
The diverting apparatus 310 also includes an elongated coupling 391, which is a collar used to connect the upper and lower casing strings 340 and 341 to one another. An upper portion of the elongated coupling 391 is connected to a lower portion of the upper casing 340 by a threadable connection 342. Similarly, a lower portion of the elongated coupling 391 is attached to an upper portion of the lower casing 341 by a threadable connection 343. The elongated coupling 391 has a second cutting apparatus 395 located on its outermost portion. In the alternative, only one casing (not shown) may have a second cutting apparatus 395 disposed thereon, which is not necessarily attached by a threadable connection. The outer diameter of the second cutting apparatus 395/elongated coupling 391 is larger than the outer diameter of the first cutting apparatus 350. The second cutting apparatus 395 extends along a substantial portion of the length of the elongated coupling 391, and even along the lower portion of the elongated coupling 391, so that the cutting apparatus 395 cuts into the formation 320 as the diverting apparatus 310 is forced progressively downward to form the wellbore 330. The second cutting apparatus 395 possesses hole-opening blades which increase the inner diameter of the upper portion of the wellbore 330.
In operation, the diverting apparatus 310 is urged into the formation 320 by downward axial force applied from a surface 305 of the wellbore 330. The elongated coupling 391 of the diverting apparatus 310 allows the two casings 340 and 341 to be threaded together at the well site, so that the diverting apparatus 310 does not have to be pre-manufactured on the casing 340 or 341. In the alternative, the second cutting apparatus 395 may be pre-manufactured on the casing string (not shown). As described above in relation to the other embodiments, pressurized fluid is introduced into the diverting apparatus 310 through the inner diameter of the upper casing 340 as the casing 340, 341 penetrates into the formation 320 to form the wellbore 330, and then the fluid flows into the lower casing 341, through the at least one nozzle 355, up through a second annular space 389 between an inner diameter of the wellbore 330 and an outer diameter of the lower casing 341, up through a first annular space 390 between the inner diameter of the wellbore 330 and an outer diameter of the upper casing 340, and to the surface 305 of the wellbore 330.
While the diverting apparatus 310 is moving axially downward through the formation 320 and the fluid is circulating, the first cutting apparatus 350 cuts into the formation 320 to form a lower portion of the wellbore 330 approximately equal to its diameter. Likewise, the second cutting apparatus 395 at the same time cuts into the formation 320 to form an upper portion of the wellbore 330 approximately equal to its diameter. The outer diameter of the upper portion of the wellbore 330 is larger than the outer diameter of the lower portion of the wellbore 330 because of the difference in diameter between the first cutting apparatus 350 and the second cutting apparatus 395.
Because of the difference in diameters between the upper and lower portions of the wellbore 330, the first annular space 390 between the outer diameter of the upper casing 340 and the inner diameter of the upper portion of the wellbore 330 is larger than the second annular space 389 between the outer diameter of the lower casing 341 and the inner diameter of the lower portion of the wellbore 330. The axial movement is halted when the diverting apparatus 310 reaches its desired depth in the wellbore 330.
The first annular space 390 at the top of the wellbore 330 is larger than the second annular space 389 at the bottom of the wellbore 330 as a result of the enlarged diameter second cutting apparatus 395, so that a larger diametral clearance exists at the upper portion of the wellbore 330 than at the lower portion of the wellbore 330. The larger diametral clearance allows gravity to cause the casing to buckle in a direction. The direction in which gravity causes the casing to buckle is illustrated by the arrows disposed within the first annular space 390. Fulcrum force is illustrated by the arrows perpendicular to the axis of the casing 340, 341 and adjacent to the second cutting structure 395. A force in the opposite direction caused by formation 320 frictional resistance is depicted by the arrow perpendicular to the axis of the first cutting apparatus 350. The effect of the forces shown by the arrows in
Again, a survey tool (not shown) placed in a landing seat (not shown) as described above may be used to determine whether the diverting apparatus 310 is bent in the desired direction at the desired angle. Once the diverting apparatus 310 is deviated into the desired angle, the first and second casings 340 and 341 are cemented into place by a setting operation as described above. All of the components disposed within the inner diameter of the casing 340 are preferably made of drillable material so that they may be drilled through after the setting operation so that the inner diameter of the casing 340 is essentially hollow for subsequent wellbore operations. Subsequent casings (not shown) are then run into the wellbore 330 and hung from the existing lower casing 341. The subsequent casings are biased in the desired direction at the desired angle because they essentially conform to the angle set by the original casings 340 and 341.
In the operation of the embodiments of
Finally,
The drilling apparatus 522 includes a drill string 523 with a first cutting apparatus 550 connected to its lower end. The first cutting apparatus 550 is smaller in diameter than the second cutting apparatus 595, so that the second cutting apparatus 595 possesses hole-opening blades which enlarge the inner diameter of the upper portion of the wellbore 530. The first cutting apparatus 550 has a cutting structure 551 attached to its lower end, at least one side parallel to a wellbore 530, and its backside 526 at an angle from the wellbore 530. The first cutting apparatus 550 has at least one nozzle 555 which allows fluid to flow into and in from a formation 520. Threads 501 are preferably located on an upper end of the drill string 523 on its inner diameter.
The operation of the diverting apparatus 510 and the drilling apparatus 522 is shown in
After the diverting/drilling apparatus 510/522 is drilled into the desired depth in the wellbore 530 at which to divert and set the casing string 540, a working string 503 or some other retrieving tool is lowered into the inner diameter of the casing string 540 (the working string 503 is shown in
As seen in
Finally, the casing string 540 is bent from the surface 505 to a side at an angle. Because of the larger first annular space 590 at the upper portion of the casing string 540, the casing string 540 is fixed at its lower end but moves through the first annular space 590 at its upper portion so that the casing string 540 is biased at an angle. The additional casing strings may then be hung off of the casing string 540 at the angle at which the casing string 540 is biased, allowing the wellbore 530 to deviate in the desired direction at the desired angle.
In the embodiments shown in
Furthermore, in any of the embodiments shown in
The diverting apparatus of the present invention and methods for their use allow effective diversion of a wellbore in a direction by deflecting a string of casing inserted into the wellbore. The apparatus and methods are simple to build and permit the wellbore diversion to be accomplished while drilling with casing in a subterranean wellbore. Accordingly, the apparatus and methods of the present invention aid in preventing the unwanted intersection of valuable subterranean wellbores.
The diverting apparatus of
In the most preferable embodiment of
In conventional drilling operations, hydraulic horsepower is delivered to the cutting structure through one or more very restrictive orifices or nozzles (commonly termed “bit nozzles”) located in the cutting structure. The nozzles are usually located in the body of the cutting structure proximate to the bottom of the wellbore. The function of the nozzles is primarily to puncture the earth formation with “jet” impacts to facilitate formation of the wellbore, then to carry the cuttings up to the surface through the annulus between the wellbore and the casing. Additional functions of nozzles and the fluid flow therethrough include cleaning the cutting structure, cooling the bit cutters, and cleaning the bottom of the wellbore. For the nozzles to perform this function, the horsepower of the fluid flowing through the nozzles must be high during jetting. Because of the high horsepower of the hydraulic fluid traveling through the nozzles while jetting, the nozzles are subjected to extremely high erosion caused by pressure drop of the drilling fluid across the nozzles (e.g., from 500 to 3000 psi) and high velocity of the fluid through the nozzles (e.g., from 200 to 800 ft/s).
The necessary high flow rate of fluid through the nozzles to perform an adequate jetting operation requires that the nozzles be made of materials which allow the nozzles to be sufficiently hard and tough to withstand the erosion due to the fluid through the nozzles. Typically, therefore, a hard and tough material such as tungsten carbide and/or ceramic is used to jet into the formation with a drill string in conventional drilling operations, as nozzles constructed from one or more of these materials may endure for thousands of hours without suffering fatal damage from erosion. Drilling with casing operations, however, such as those that are shown in
Drilling with casing operations may require the same fluid intensity while jetting and/or rotating the casing as is required when circulating drilling fluid in the drill string while drilling. The amount of time that the fluid intensity must be maintained during drilling may be less for drilling with casing operations than in traditional drilling operations, however.
In the embodiments of the present invention shown in
As shown in
The present invention provides drillable nozzles for use while drilling with casing. For the cutting structure 1615 to be drillable, the base material and the nozzle(s) of the cutting structure 1615 must be soft enough to allow subsequent casing 1620 to drill therethrough. However, a nozzle constructed of a sufficiently soft material used in a drilling with casing application may only last a few hours under intense fluid erosion due to jetting. While enlarging the nozzle diameter to reduce velocity of the fluid through the nozzle aids in increasing nozzle longevity, this design remains problematic because the velocity of the fluid through the nozzle(s) may be so decreased that the casing no longer sufficiently drills through the formation during the jetting process.
In the embodiment shown in
The drillable nozzle 1700 has one or more stressed portions therein, specifically shown as one or more stressed notches 1710 in
An o-ring groove 1705 may exist within the outer diameter of the body of the nozzle 1700 around its circumference for disposing an o-ring (not shown) therein to seal the nozzle 1700 within a body of the tool in which the nozzle 1700 is disposed, such as a cutting tool (not shown). In one embodiment, a filler material 1715, preferably an extrudable material such as epoxy or vulcanized rubber, is disposed at least partially within the notches 1710 when the notches 1710 extend the length of the nozzle 1700 so that the o-ring may seal in the o-ring groove 1705.
The embodiment shown in
In the embodiments of
In the embodiment of the present invention illustrated in
The flow tube 1910 has a substantially uniform inner diameter bore along its length to form a substantially straight bore through the flow tube 1910. The substantially straight bore of the flow tube 1910 maintains a minimal thickness along the length of the flow tube 1910, thus enhancing drillability of the flow tube 1910 with a subsequent cutting structure, as any profile of the flow tube 1910 other than a straight bore therethrough would require an increase in material thickness perpendicular to the axis of the flow tube 1910. The material thickness perpendicular to the axis of the flow tube 1910 is presented to the subsequent cutting structure for drilling therethrough. Also, the internal profile of the flow tube 1910 formed by the substantially straight bore therethrough potentially decreases erosion of one or more portions of the nozzle 1900 because the fluid does not have to change direction due to obstructions within the bore when flowing through the nozzle 1900.
The nozzle retainer 1920, which is preferably constructed of a relatively soft, drillable material such as copper or plastic, retains the flow tube 1910 therein. The flow tube 1910 is preferably mounted within the nozzle retainer 1920, which is a tubular-shaped body with a longitudinal bore therethrough. The nozzle retainer 1920 may include an installation and removal feature, such as slots 1940 shown in
An integral feature of the nozzle assembly 1900 is the extended length of the flow tube 1910. Due to the extended length of the flow tube 1910, the flow tube 1910 may be positioned as desired within the nozzle retainer 1920 by moving the flow tube 1910 up or down (right or left as shown in
The nozzle retainer 1920 is preferably constructed of a relatively soft, drillable material such as copper or plastic. The material that the retainer 1920 is made from is softer than the material of the flow tube 1910. Also, the material of the flow tube 1910 is more resistant to corrosion than the material of the retainer 1920. The internal bore of the retainer 1920 is profiled to produce a controlled fit over the outer diameter of the flow tube 1910, with a gap 1947 left between the flow tube 1910 and the retainer 1920 which is preferably substantially filled with a suitable adhesive 1945 for retaining the flow tube 1910 in the desired position within the retainer 1920.
The retainer 1920 is seated within a nozzle profile 1965 in a tool body 1925. The tool is preferably an earth removal member for cutting into an earth formation, and even more preferably a cutting structure such as a drill bit or drill shoe. The tool body 1925 is preferably constructed of a relatively soft, drillable material such as copper or plastic. An outer surface of the retainer 1920 has a seal groove 1907 having a seal 1905 therein for preventing fluid flow across the interface of the outer surface of the retainer 1920 and the nozzle profile 1965 of the tool body 1925. An external thread 1915 secures the nozzle assembly 1900 within the tool body 1925.
Advantageously, the embodiment of
An alternate embodiment of a nozzle assembly 2000 of the present invention is shown in
The nozzle assemblies 1900, 2000 shown in
The flow tube 2180 is constructed from a relatively hard material such as ceramic, tungsten carbide, or PDC to limit erosion of the flow tube 2180, as described in relation to
A relatively soft, drillable material such as copper or plastic is utilized to form the nozzle retainer 2120. The material making up the flow tube 2180 is harder than the material of the retainer 2120 and tool body 2125, and the material of the flow tube 2180 is more resistant to corrosion than the material of the retainer 2120. The drillability of the soft material allows the nozzle retainer 2120 to be of a larger thickness at the portion adjacent to the smaller diameter portion of the flow tube 2180 than its thickness at the other portions of the flow tube 2180. The retainer 2120 inner diameter thus essentially conforms to the outer diameter of the flow tube 2180.
The nozzle assembly 2100 is disposed in a tool body 2125, which is preferably an earth removal member such as a drill shoe or a drill bit. The tool body 2125 is preferably constructed of a relatively soft (at least compared to the flow tube 2180), drillable material such as copper, aluminum, cast iron, plastic, or combinations thereof. The material of the tool body 2185 may or may not be the same as the material of the retainer 2120. A seal 2105 is disposed within a seal groove 2107 formed in an outer diameter of the retainer 2120 to prevent fluid from traveling in the area between the inner diameter of the tool body 2125 and the outer diameter of the retainer 2120. Retaining threads 2115 are located between the tool body 2125 and the retainer 2120 for connecting the nozzle assembly 2100 to the tool body 2125.
The nozzle assembly 2100 is characterized by an extended exit. The extended exit is represented by an exit standoff 2160, which is the length of the flow tube 2180 which extends past the end of the tool body 2125 from which fluid flows upon exit from the flow tube 2180. The exit standoff 2160 diverts the flow turbulence into an area away from the nozzle retainer 2120 and the tool body 2125.
Shown in
In addition to their use in drillable applications, the above embodiments shown in
The alternate embodiments of
The nozzle body may be made of two materials, wherein the surface of the through-bore is made of a first material, wherein said first material is of relatively thin construction and has a high resistance to erosion, and wherein the remainder of the nozzle body is made of a second material that is easily drillable. The first or surface material may be a hard chrome. Alternatively, tungsten carbide or suitable alloys may be used, their suitability being assessed by their ability to withstand erosive forces from the well fluid jetted through the through-bore.
The second material forming substantially the majority of the nozzle body may be made typically of a softer metal, such as nickel, aluminum, copper or alloys of these. Preferably, the second material may be copper and the surface or first material is hard chrome, wherein the hard chrome is applied to the copper body by electro-plating.
Alternatively, a nozzle in accordance with the present invention may be made of a rubber material. In this respect, it is noted that while rubber is typically not a “hard” material, it does nevertheless have a high resistance to erosion. Moreover, rubber materials may be easily drilled by subsequent drilling bits. A nozzle in accordance with invention may be made of one or more materials and need not be made entirely or even partially of a metal material. Polyurethane or other elastomers may also be used.
Referring firstly to
It is recognized in the invention that the nozzle through-bore 4 is intended to receive drilling fluid at high velocities and with high pressure differentials. Accordingly, the surface 5 of the through-bore 4 is constructed of a material that is suitable for withstanding the abrasive and eroding nature of the drilling fluid in use. Not only must the surface of the through-passage withstand the eroding forces of the drilling fluid, but in view of the proximity of the nozzles to the cutting surface of the drill bit, excessive wear may be induced in the event of a nonresistant material being employed as a result of the impact of small rock particles and other debris cut by the drill bit from the well formation. The erosive effect of rock particles within drill bit nozzles is well known and documented. For this reason, the surface of the through-bore 4 is preferably made from a hard material which, in an example embodiment of
The surface material will typically be chosen as one which is able to be combined with a softer, drillable material whereby this softer, drillable material may form substantially the body of the drill bit nozzle, with the exception of the surface herein before mentioned. In the example embodiment illustrated in
In
An advantage of the present invention will be apparent from the method of use of the drill bit nozzle as shown in
When nudging casing into the formation, it is sometimes useful to form a casing string made up of a plurality of casing sections. Making up the casing string involves rotating one casing section relative to another casing section to threadedly connect the casing sections together. Many of the directional drilling tools described in the figures of the present application include biasing tools (e.g., eccentric stabilizer and/or directional jet) disposed on the casing or within the casing, the location of which must be tracked from the surface of the wellbore to allow the operator to maintain the direction and angle of the deviated wellbore while drilling with the casing. One method of tracking the position of the biasing tool on the casing involves marking the position of the biasing tool when the casing having the biasing tool thereon is first lowered into the formation (“stoking or scribing in the hole”). Marking the position may be accomplished by drawing a vertical chalk line along the casing as one casing section is threaded onto another. Then, when the made-up casing string is lowered into the wellbore, the portion of the marked casing section which remains located above the wellbore (e.g., by a spider on a rig floor) becomes the reference point for marking a chalk like after the next section of casing is threaded onto the casing string.
An additional method of tracking the position of the biasing tool, which may be used in addition to the scribing method, is accomplished by the mechanism shown in
Additional embodiments of the present invention generally provide improved methods and assemblies for drilling with casing (DWC). In contrast to the prior art, drilling assemblies according to the present invention are supported between an attachment point at a bottom of the casing and the point of drilling contact by one or more adjustable stabilizers. The stabilizers may have one or more adjustable support members that may be placed in a first (run-in) position giving the stabilizer a sufficiently small outer diameter to be run in through the casing with the drilling assembly. The support members may then be placed in a second position giving the stabilizer a sufficiently large outer diameter to engage an inner wall of the wellbore to provide support for the drilling assembly during drilling.
Additional embodiments of the present invention provide directional force for directionally drilling the assembly on the casing rather than the BHA. Moreover, embodiments of the present invention reduce the requisite length of the rat hole below the casing, thereby decreasing the amount by which the casing must be lowered into the rat hole after the BHA has drilled to the desired depth at which to place the casing within the wellbore.
For different embodiments, the drilling assemblies of the present invention may be adapted to operate in either a rotary or slide mode. For some embodiments, in an effort to decrease drilling time, an expandable bit having a higher removal rate than the conventional combination of an under-reamer and pilot bit may be utilized. While embodiments of the present invention may be particularly advantageous to directional drilling with casing, some embodiments may also be used to advantage in non-directional DWC systems. Such embodiments may lack the bent subassemblies shown in the following figures.
As illustrated, for some embodiments, the stabilizer 4202 may be positioned above a biasing member, such as a bent subassembly 4114 (“bent sub”) used to bias the BHA 4200 in the desired direction. The bent sub 4114 may be fixed or adjustable to tilt the face of the bit 4204, typically from 0° to approximately 3° with respect to the centerline of the BHA 4200. As previously described, the bent sub 4114 may be integral with a downhole motor 4112. The number of adjustable stabilizers 4202 utilized in a system may depend on a number of factors, such as the weight-on-bit applied to the BHA 4200, the length of the BHA 4200, desired wellbore trajectory, etc.
While a conventional pilot bit and under reamer may be used for some embodiments, the expandable bit 4204 generally provides an increased removal rate and performs the same operations (e.g., forming an expanded hole below the casing 4104, allowing the casing string to advance with the wellbore). The increased removal rate may be accomplished by providing a greater density of cutting elements (“cutter density”) in contact with the wellbore surface. For example, cutting members 4205 of the bit 4204 may include cutting elements arranged in full complement with the hole profile to achieve an optimal penetration rate. An example of an expandable bit is disclosed in International Publication Number WO 01/81708 A1, which is incorporated herein in its entirety. As described in the above referenced publication, cutting elements of the bit 4204 may be made of any suitable hard material, such as tungsten carbide or polycrystalline diamond (PDC).
Operation of the BHA 4200 may be best described with reference to
At step 3306, the bit 4204 is expanded to have an outer diameter greater than an outer diameter of the casing 4104. For example, as illustrated in
At step 3308, the stabilizer 4202 is adjusted for directional control of the drilling assembly. For example, initially, an outer diameter of the stabilizer 4202 may be adjusted from the first (run-in) position to a second position having a sufficiently large diameter to engage the inner walls of the wellbore 4102 to support the BHA 4200 while drilling. During the drilling process, as will be described in greater detail below, the stabilizer 4202 may be adjusted to a third position (between the run-in position and the second position) to vary the under-gage amount (e.g., separation between support members 4203 and the inner walls of the wellbore 4102), in an effort to control the trajectory of the hole.
Means for adjusting the stabilizer 4202 may vary with different embodiments. For example, as illustrated in
In either case, adjustments to the stabilizer 4202 (between the various positions) may be made by any suitable means, such as hydraulic means (in a similar manner as described above with reference to the expandable bit 4204), mechanical means, and electrical or electro-mechanical means, etc. Regardless, the stabilizer 4202 may be designed for use in rotary and/or slide mode. For example, in slide mode, the stabilizer 4202 provides drill string centralization and prevents the BHA from leaning onto one side of the hole. For some embodiments, the stabilizer 4202 may include sensors that monitor relative movement of the casing 104 in order to allow the stabilizer 4202 to rotate with the casing 4104 or to slide as the casing 4104 is being rotated to aid in the control of the direction of the hole. In either case, the stabilizer 4202 may prevent BHA 4200 from buckling (and leaning to one side) when weight-on-bit is applied to the BHA 4200. By preventing deflection of the BHA 4200 within the wellbore 4102, the stabilizer 4202 may also reduce the amount of axial and lateral vibration.
As previously described, excessive vibration, particularly in rotary mode, may lead to less than optimal contact between the bit 4204 and the formation 4103, leading to reduced penetration rate and a corresponding increased drilling time, which increases production costs. Further, excessive vibration may also lead to catastrophic harmonics which may damage and/or destroy the various components of the BHA 4200. In an effort to further reduce vibration, the BHA 4200 may also include a flexible collar 4206, which may be designed to prevent vibration from traveling from the bent subassembly 4114 to an upper portion of the BHA 4200 (e.g., any portion above the flexible collar 4206). The flexible collar 4206 may be made of any suitable flexible-type materials capable of withstanding harsh downhole conditions.
At step 3310, the bit 4204 is rotated to drill a hole having an outer diameter larger than the outer diameter of the casing 4104. As previously described, embodiments of the BHA 4200 may be operated in a rotary mode or a slide mode. In rotary mode, the bit 4204 may be rotated with the casing 4104 and guided with a rotary-steerable assembly (not shown), having adjustable pads that may be used to “push off” the inner walls of the formation 4102 to adjust the deviation of the bit angle from center. In slide mode, the bit 4204 may be rotated by a steerable downhole motor 4112, which typically provides a high speed of rotation and a high rate of removal without the need to rotate the casing 4104. When operating in either mode, the stabilizer 4202 provides centralization and prevents the BHA 4200 from leaning to one side of the hole, thus allowing better control of the trajectory of the hole.
At step 3312, the trajectory of the hole is monitored. As previously described, in conventional DWC systems, the hole may be steered by geological indicators logged at certain points while drilling (logging while drilling, or “LWD”) using at least one LWD tool. While this log may be used to reconstruct and verify the wellbore path after drilling, this may be too late to make corrections. However, by monitoring the trajectory of the hole while it is being drilled (measuring while drilling, or “MWD”), embodiments of the present invention may allow for corrections to be made at the surface, for example by adjusting weight on bit, adjusting angle of the bent sub, and/or steering the motor 4112.
Further, as previously described, the stabilizer 4202 may be adjusted in response to a monitored trajectory. For example, the support members 4203 may be adjusted to provide a separation between the stabilizer 4202 and the inner surface of the wellbore 4102. The separation between the stabilizer 4202 and the inner surface of the wellbore 4102 (as shown in
The trajectory of the wellbore 4102 may be monitored with a measurement-while-drilling (MWD) tool 4107 which, as shown, may be disposed anywhere along the BHA 4200. The MWD tools 4107 may be generally used to evaluate the trajectory of the wellbore 102 in three-dimensional space while extending the wellbore 4102. Therefore, the MWD tool 4107 may generally include one or more sensors to measure the trajectory (e.g., azimuth and inclination) of the wellbore, such as a steering sensor, accelerometer, magnetometer, or the like.
Of course, the MWD tool 4107 may also have sensors to monitor one or more downhole parameters, such as conditions in the wellbore (e.g., pressure, temperature, wellbore trajectory, etc.) and/or geophysical parameters (e.g., resistivity, porosity, sonic velocity, gamma ray, etc.). For some embodiments, the MWD tool 4107 may log such parameters for later retrieval at the surface. Thus, the MWD tool 4107 may also perform the same functions as conventional LWD tools. Regardless of whether these parameters are logged or telemetered to the surface in real time, measuring these parameters while drilling may save an additional trip down the wellbore for the sole purpose of such measurements.
Any suitable telemetry techniques may be utilized to communicate the wellbore trajectory (and possibly any other parameters) monitored by the MWD tool 4107 to the surface of the wellbore 4102. Examples of suitable telemetry techniques may include electronic means (e.g., through a wireline or wired pipe) and/or digitally encoding data and transmitting to the surface as pressure pulses in a mud system using sensing devices including, but not limited to, one or more of the following: mud-pulse telemetry device; mud pulse on gyroscope device; gyroscopic telemetry device on wireline; gyroscopic telemetry electromagnetic device; gyroscopic telemetry acoustic device; gyroscopic telemetry mud pulse device; magnetic dipole including single shot and telemetry; wired casing as shown and described in relation to U.S. application Ser. No. 10/419,456 entitled “Wired Casing” and filed Apr. 21, 2003, which is incorporated by reference herein in its entirety; and fiber optic sensing devices. Any combination of sensors and/or telemetry may be utilized in the present invention. Regardless of the method used, based on the monitored trajectory as received at the surface, adjustments may be made at the surface (e.g., adjustments to the stabilizer 4202, weight on bit, speed of rotation, steering of the motor 4112 or rotary-steerable assembly, etc.).
Accordingly, the operations 3308-3310 may be repeated to extend the wellbore to a desired depth along a well-controlled trajectory. Once the desired depth is reached, the BHA 4200 may be retrieved from the wellbore. For example, the BHA 4200 may be retrieved by unlatching the casing latch 4106 and placing the stabilizer 4202 and expandable bit 4204 back in the run-in positions (as shown in
However, retrieving the BHA 4200 through the entire length of casing 4104 may require a significant amount of time in which the formation around the newly drilled (and uncased) portion of the wellbore may settle, thereby making it difficult to subsequently advance the string of casing 4104. Therefore, for some embodiments, prior to completely retrieving the BHA 4200, the BHA 4200 may be only partially raised through the casing 4104 (e.g., enough that the bit 4205 is at least partially within the casing 4104). After partially raising the BHA 4200, the casing 104 may then be advanced into the newly drilled portion of the wellbore, for example, by adding additional sections of casing 4104 from the surface. Because partially raising the BHA 4200 may require significantly less time than completely raising the BHA 4200 to the surface (as during retrieval), the likelihood of the formation settling prior to advancing the casing 4104 is reduced. After advancing the casing 4104, the BHA 4200 may then be completely retrieved.
While the adjustable stabilizer 4202 is shown in
In another embodiment, the expandable bit 4205 may be replaced with a combination of a pilot bit and underreamer. Embodiments of the present invention provide methods and assemblies for improved drilling with casing (DwC). By providing an adjustable stabilizer, the drilling assembly may be adequately supported, thus avoiding excessive deflection and vibration that commonly occurs in conventional DwC systems. Further, by utilizing measurement-while-drilling equipment, trajectory of the wellbore may be measured in real time, thus allowing corrections of the trajectory to be made at the surface increasing the likelihood a desired trajectory will be achieved. A further additional embodiment may include closed-loop drilling to control the diameter of the adjustable stabilizer or motor bend angle, or a 3-D rotary steerable system. The closed-loop control could be a microprocessor, either uphole or downhole.
The casing 2404 includes one or more casing sections.
When employed to connect the BHA 2400 to the casing 2404, the BHA 2400 with the spring-loaded axial and torque blades 2407 and 2405 are run through the casing 2404. Once the blades 2407 and 2405 reach the profiles 2413 and 2415 in the inner diameter of the profile collar 2411, the bias force from the spring-loaded blades 2407 and 2405 causes the blades 2407 and 2405 to snap out into their respective profiles 2413 and 2415. The torque blades 2405 rotate a few degrees before snapping out into the profile collar 2411. The axial blades 2407 prevent the BHA 2400 from translating axially relative to the casing 2404, and the torque blades 2405 prevent the BHA 2400 from rotating relative to the casing 2404. While the profiles 2415 and 2413 are shown existing in the profile collar 2411 in
An upper portion of the BHA 2400, shown here as the upper position of the casing latch 2406, possesses one or more packing elements 2417 on its outer diameter for sealingly engaging an annulus between the BHA 2400 and the casing 2404. The packing elements 2417 are preferably elastomeric for providing a seal between the casing 2404 and the BHA 2400. Additionally, cups 2418 located above and below the packing elements 2417 aid in sealing the annulus between the casings 2404 and the BHA 2400. The packing elements 2417 and the cups 2418 extend radially from the BHA 2400 circumferentially around the body of the casing latch 2406.
The upper end of the casing latch 2406 has threads 2419, preferably female threads, and/or a fishing profile to allow collets to latch into or around (see U.S. Pat. No. 3,951,219, which is herein incorporated by reference in its entirety) for connecting the BHA 2400 to the surface with a tubular body (not shown) so that the BHA 2400 can be retrieved at the desired time. Additionally, the upper end may have a GS profile. Possible tubular bodies which may retrieve the BHA 2400 include but are not limited to drill pipe, coiled tubing, coiled rod, or wireline. Below the casing latch 2406 in the BHA 2400 is a resistivity sub 2420 for housing one or more resistivity sensors (not shown) therein for use in taking real-time or periodic resistivity measurements. Around the resistivity sub 2420 is a stabilizer 2422 which extends radially from and preferably circumferentially around the BHA 2400. The stabilizer 2422 bridges the annulus between the BHA 2400 and the casing 2404 and maintains the position of the BHA 2400 within the casing 2404 at a preferred axial location to stabilize the BHA 2400 relative to the casing 2404.
The resistivity sub 2420 may contain one or more geophysical sensing devices capable of measuring parameters such as formation resistivity, formation radiation, formation density, and formation porosity. The sensing devices may be latched therein by embodiments of mechanisms shown in
Below the resistivity sub 2420 in the BHA 2400 is an MWD/LWD sub 2424, which may house one or more MWD or LWD sensing devices including, but not limited to, one or more of the following: mud-pulse telemetry device; mud pulse on gyroscope device; gyroscopic telemetry device on wireline; gyroscopic telemetry electromagnetic device; gyroscopic telemetry acoustic device; gyroscopic telemetry mud pulse device; magnetic dipole including single shot and telemetry; wired casing as shown and described in relation to U.S. application Ser. No. 10/419,456 entitled “Wired Casing” and filed Apr. 21, 2003, which is incorporated by reference herein in its entirety; and fiber optic sensing devices. Any combination of sensors and/or telemetry may be utilized in the present invention. As with the resistivity sub 2420 sensing devices, the MWD/LWD sub 2424 sensing devices may be latched therein by the mechanism shown in
Because same directional MWD and LWD sensors are magnetic, the casing 2404 surrounding the MWD/LWD sub 2424 must usually be non-magnetic. However, because the casing 2404 is left downhole when drilling with casing, and because non-magnetic casing is more expensive than the magnetic casing usually drilled with when drilling with casing, it is desirable in some situations to drill with magnetic casing. To this end, a gyroscope may be utilized as the directional MWD/LWD sensor to eliminate the necessity to use non-magnetic casing around the MWD/LWD sub 2424. Magnetic casing may then be disposed around the MWD/LWD sub 2424. A preferred gyroscopic sensor for use in the present invention is a Gyrodata Gyro-Guide GWD gyro-while-drilling tool, as shown and described in Gyrodata Services Catalog, 2003, at page 31. Gyro-Guide is a fully integrated guidance system housed in the MWD tool string (here, the BHA 2400) which includes wireless telemetry for surveying while drilling. Use of the Gyro-Guide allows gyro-while-drilling rather than the operator having to repeatedly stop the drilling process, place the surveying tool (e.g., gyroscope) into the casing 2404 with wireline, take measurements, then remove the surveying tool prior to drilling further.
Below the MWD/LWD sub 2424 in the BHA 2400 is a mud motor 2425. Connected below the mud motor 2425 is an underreamer 2426 and a pilot bit 2428. The pilot bit 2428 and the underreamer 2426 may be replaced by a bi-center bit in one embodiment. The mud motor 2425 provides rotational force to the underreamer 2426 and pilot bit 2428 relative to the mud motor 2425 through a motor bearing pack 2429 when it is desired to rotate the pilot bit 2428 relative to the BHA 2400 and the casing 2404 and rotationally drill into the formation. The mud motor 2425 utilized may be similar to the mud motor shown and described in relation to
An optional stabilizer 2430 similar to the stabilizer 2422 may be located around the outer diameter of the BHA 2400 at a location near the connection between the MWD/LWD sub 2424 and the mud motor 2425. The stabilizer 2430 is preferably located adjacent to an eccentric casing bias pad 2435 (described below). Like the stabilizer 2422, the stabilizer 2430 also maintains the axial location of the BHA 2400 relative to the casing 2404 by bridging the annulus between the BHA 2400 and the casing 2404. An additional concentric stabilizer 2432 is disposed concentrically around the outer diameter of the mud motor 2425 near the lower end of the casing 2404 to stabilize the lower end of the BHA 2400 relative to the casing 2404.
The primary impetus for the directional bias of the casing string 2404 (with respect to the vertical axis of the casing string 2404 entering the formation from the surface) exists due to an eccentric casing bias pad 2435. The casing bias pad 2435 is disposed on only one side of the casing 2404 on the outer diameter of the casing 2404 to push the centerline of the casing 2404 at an angle with respect to the wellbore centerline, thus eccentering the casing 2404 relative to the wellbore. The casing bias pad 2435 is mounted near the lower end of the casing 2404. The directional bias angle of the casing 2404 is in the opposite side of the casing 2404 from the side of the casing 2404 to which the casing bias pad 2435 is attached. For example, as shown in
With the eccentric casing bias pad 2435, the directional force for directionally drilling the wellbore at an angle is provided essentially perpendicular to the portion of the casing bias pad 2435 perpendicular to the axis of the casing 2404. The force is translated from the outer portion of the casing bias pad 2435 to the casing 2404 so that the directional force is primarily born by the casing 2404 rather than the BHA 2400, primarily because the BHA 2400 is housed almost completely within the casing 2404 rather than a large portion of the BHA 2400 extending below the casing 2404. In the embodiment shown in
The casing latch 2406, in addition to performing the function of latching the BHA 2400 to the casing 2404, orients the face of the MWD or LWD tool (not shown) located within the BHA 2400 to the casing bias pad 2435 so that the location of the casing bias pad 2435 on the casing 2404, and consequently the angle at which the casing 2404 is drilling, is readily ascertainable with respect to some reference point. The torque blades 2405 of the casing latch 2406 maintain the rotational position of the BHA 2400 relative to the casing 2404, therefore orienting the sensor with respect to where the eccentric pad 2435 is located by preventing rotation of the BHA 2400 within the casing 2404. Similarly, the MWD/LWD tool may be latched into the MWD/LWD sub 2424 by the apparatus and method shown and described in relation to
The casing latch 2506 of
Instead of the mud motor 2425 of
An additional difference between the system of
Just as in the embodiment of
In the operation of the embodiment of
As in the embodiment shown in
In the embodiments of
In the above embodiments shown and described in relation to
The BHA 2400, 2500 components, including the latch 2406, 2506; MWD/LWD sub 2424, 2524; and resistivity sub 2520, may be arranged in a different order than is shown in
The operation of embodiments depicted in
Instead of a bent motor 2550 as shown in
In
In
Referring initially to
To drill into the earth and thereby form borehole 10A, a drill string 20A, comprising a plurality of individual lengths of pipe or tubing 22A (one such shown in
Referring now to
Referring still to
Referring still to
To retrieve the survey tool 60A from the well where the tool 60A becomes separated from the wireline 102A, cover portion 108A may include a fishing neck 112A thereon for retrieving of the survey tool 60A with a fishing tool (not shown). In another embodiment, the tool 60A may be intentionally separated from the wireline 102A and left in place. In another embodiment still, the tool 60A may be pre-assembled with shoe 52A only to be retrieved later by wireline or pipe. The body 104A further includes a plurality of flow passages 116A extending therethrough which enable fluids to flow between the hollow portion 28A of the drill string 20A and the interior volume 118A of the body 104A. A plurality of stabilizers 120A are located on the outer surface of body 104A help center the survey tool 100A in the drill string 20A as it is lowered from the surface through hollow portion 28A.
Within survey tool 60A and connected to wireline 102A passing through upper cover portion 108A is a diagnostic apparatus 114A. In the embodiment shown, this diagnostic apparatus 114A is a geosensor and sender combination which, in conjunction with a computer and computer program therein, is able to determine orientation of the borehole 10A in the earth, and thus is needed to ensure that the borehole 10A is progressing in the desired direction once the rotational position of the survey tool 60A is known.
Referring now to
In the preferred embodiment hereof, the drill shoe includes a cutting apparatus which may be a traditional rock bit, a drill motor, or the like, preferably configured to be drilled through by a subsequent, smaller drill shoe passed down the casing. Alternatively, the drill shoe may include a jet section having a plurality of fluid jets extending from a central bore thereof (not shown) to the exterior thereof in a known circumferential position. Preferably, as is known in the art, the fluid jets may be selectively controlled to enable jetting into the formation for removal of formation materials and thereby create a deviation in the direction of the borehole direction. Thus, the drill string (or drill motor) may be rotated to drill ahead or the jets may be oriented by rotational positioning and selection thereof to drill directionally. The drill shoe also preferably includes a plurality of mud passages therethrough, through which drilling fluids may pass to lubricate or cool the cutting surface and enable the removal of cuttings from the borehole as the drilling fluid is recirculated to the earth's surface.
The orientation or rotational alignment of the mule shoe profile 54A, being known prior to the placement of the survey tool 60A therein, enables multiple functions to be accomplished downhole with a high degree of reliability. In one aspect, the survey tool 60A may be a gyroscope, which is adapted to acquire information relating to wellbore position. The position information is communicated to the surface via the wireline 120A. Particularly, surface components or controllers may receive information relating to the orientation of the gyro and the rotational position of the casing, including the bent sub. In turn, the position of the casing or the bent sub may be changed by rotating the casing at the surface to provide the desired orientation or position. Thereafter, the gyro may be removed via the wireline 120A, or if necessary via a fishing tool. After orientation, drilling or jetting through selective ports of the jet portion of the drill shoe may be undertaken to establish a new or desired direction of the borehole. The new direction of the borehole may be determined and verified by landing the gyro on the muleshoe profile 54A. Any additional directional modification may be performed, as needed, according to the method described above.
Alternatively, a measure-while-drilling tool (“MWD tool”) or LWD tool 600A having a survey tool 660A may be used to determine and steer the drill shoe (located below 620A) as drilling progresses, as illustrated in
Referring to
Referring now to
As with survey tool 60A, the orientation or rotational alignment of the survey tool 200A is known with respect to the position of the bent sub, the drill shoe, or the jet section, as the orientation of the slot 58A is known with respect to these portions of the drill string when they are assembled together before entering the borehole. Thus, survey tool 200A may comprise a gyro, and signals therefrom indicative of the direction in which the borehole is progressing and the alignment or orientation of the drill shoe components may be sent on wireline 120A to the surface to enable repositioning of the drill shoe components if needed, as was accomplished with respect to the survey tool 60A. Likewise, an MWD/LWD tool could be landed in the float sub 34A and utilize the alignment provided by the slot 58A to continue drilling and steering using the MWD/LWD. While the MWD/LWD tool is landed on the float sub 34A, the MWD/LWD tool can communicate the survey information to the surface via mud pulse telemetry, thereby eliminating the need to remove the survey tool to further drill the borehole.
The float sub 34A of the present invention provides multiple useful downhole features when provided in a drill string 20A. First, the position of the shoe 52A relative to the drill bit is noted prior to placement of the float sub 34A down the borehole, thereby enabling the use of data retrieved from or calculated by the survey tool to have a meaningful relation to the face being drilled. Additionally, the shoe 52A enables a known rotational alignment of the well survey tool 60A, 200A, when seated in the float sub 34A, which likewise enables meaningful data retrieval and generation for bit heading. Further, the use of an aligning element in combination with flow through the survey tool 60A, 200A housing, allows the drilling mud or other fluid flowing down the drill string 20A to be used to ensure that the survey tool 60A, 200A remains fully seated and thus properly oriented, as surveying is occurring, and likewise allows survey to occur when fluids are flowing through the system and thus as drilling is ongoing.
In each instance, after surveying is completed and well production need be initiated, the float sub 34A components must be removed or otherwise rendered non-impeding to the production of fluid from the well. Because the survey tool 60A 200A is merely sitting in the float sub 34A, it may be easily removed from the float sub 34A such as by extending a fishing tool (not shown) and engaging fishing neck 112A to pull the survey tool from the drill string 20A, or if the wireline 102A is sufficiently strong, the survey tool may be pulled up with the wire 102A. In another aspect, the survey tool 60A, 200A may be latched in the float sub 34A with a collet assembly, secured in place with shear screws or other methods known to a person of ordinary skill whereby the survey tool may be retrieved with relative ease.
Once the survey tool is removed, the float sub 34A is used to enable cementing of the casing 22A comprising the drill string 30A in place in the borehole, to case the borehole. Specifically, cement is flowed down the interior 28A of the casing 20A, and through the float sub 34A (as flowed drilling fluids), and thence out the mud passages in the drill shoe or other cementing passages provided therefore and into the annular space between the drill string 20A and the borehole 10A and 16A. This cement may need to cure in place without backing up through the interior of the drill string before hardening. Therefore, when the cementing fluid is no longer flowed down the drill string and a secondary, lighter liquid is poured into the drill string immediately behind the cement whereby the pressure in the drill string will be less than that in the annulus between the drill string 20A and the borehole 10A and 16A, the valve assembly 68A will close over the opening of bore 66A at the underside of the housing 64A to seal the bore from entry of cement back into the hollow interior region 28A of the drill string 20A. In another aspect, one or more isolation subs (not shown) may be positioned above or below the float shoe 34A to prevent leakage of cement back up the hollow region 28A if cement leaks past valve assembly 68A.
After the cement is cured, the float sub 34A is then removed, typically by directing a drill, mill, or cutter down the drill string 20A hollow portion 28A from the surface, and physically cutting or drilling through the shoe, housing, and valve assembly. The drill, mill, or cutter will readily drill through the cement or plasticbased components of the float sub, as well as any metal portion, into small pieces which may be recovered, in part, by being carried to the surface in drilling mud. Additionally, there is a benefit to having as much of the componentry as practicable, such as valve body 48A, etc. constructed of a material which is easily ground up or drilled through yet has sufficient strength to retain its shape under pressure. Once the float sub is removed, production tubing or other production elements can easily be passed through the drill string 20A past the former location of the float sub 34A. In instances where the borehole has not yet reached its ultimate depth, an additional casing to be cemented in place having a drilling bit and a drill motor operatively attached thereto may be used to drill through the float sub 34A and the drill motor at the bottom of the drill shoe to continue drilling further into the earth.
Although the invention has been described with respect to its use in a situation where the drill string 20A is to be used, in situ, as casing, the invention is as applicable to situations where a well is separately cased with tubing. In such an embodiment, a section of the casing may be provided with float sub 34A therein in a fixed longitudinal and angular alignment, and the distance from the float sub 34A to other locations of interest such as the end of the lowestmost casing in the stack noted. Thus, the float sub 34A may be used to enable survey tool alignment and positioning in casing, although drilling may not be simultaneously occurring.
Although the float sub 34A has been described in terms of a landing platform for receiving and orienting a survey tool, float sub 34A may be modified to include additional features, for example a latching collar or other receptacle formed therein to which a latching system such as a float collar or a cementing tool may be secured. Likewise, the float sub may be configured to include a stage tool, whereby a blocking member such as a ball (not shown) may be positioned to block the bore 66A, such that cement may be directed through the stage tool portion thereof (not shown).
In another aspect shown in
The survey tool assembly 900 may include survey tools such as a MWD tool 935 and a gyro 936. In one embodiment, the survey tools 935, 936 are disposed in the body 940 of the survey tool assembly 900 using one or more centralizers 942. A mud pulser 945 may be used to transmit information from the survey tools 935, 936 to the surface. The body 940 has a retrieving latch 950 disposed at one end, and an alignment key 955 disposed at another end. The alignment key 955 is adapted to engage the receiving socket 930 in a manner that orients the survey tool assembly 900 with the fluid deflectors (bit nozzles) 925. One or more seals 908 may be used to prevent fluid leakage between the survey tool assembly 900 and the casing 910. Additionally, spring bow centralizers 960 may be disposed on the outer portion of the body 940 to centralize the survey tool assembly 900 in the casing 910.
Many survey tools are actuated by fluid flow. To this end, the survey tool assembly 900 includes a fluid inlet channel 965 to allow fluid to flow into the body 940 to actuate the MWD tool 935 and the gyro 936. However, many survey tools operate in a fluid flow range that is often below what is necessary for other operations, for example, drilling operation. Consequently, the survey tool must be retrieved prior to the subsequent, higher flow rate operation. The process of repeatedly retrieving and deploying the survey tools is time consuming and expensive. To this end, the survey tool assembly 900 according to aspects of the present invention also includes a bypass valve 970 to allow the subsequent, higher flow rate operation to be performed without retrieving the survey tool assembly 900.
In one embodiment, the bypass valve 970 is disposed at a portion of the body 940 that is below the survey tools 935, 936. The bypass valve 970 is initially biased in the closed position by a biasing member 975, as illustrated in
The bypass valve 970 may be opened by providing a higher flow rate. Specifically, the bypass valve 970 opens when the flow rate in the casing 910 overcomes the directional force of the biasing member 975. Once opened, some of the fluid in the casing 910 may be directed through the bypass valve 970 instead of the inlet channel 965, as illustrated in
In operation, the survey tool assembly 900 is assembled inside the casing 910 and is lowered into the wellbore together with the casing 910. Particularly, the alignment key 955 is situated in the receiving socket 930 to orient the survey tool assembly 900 with the fluid deflectors 925, as illustrated in
The bypass valve 970 is opened when the directional force of the spring is overcome by a higher flow rate. After the bypass valve 970 is opened, fluid flow through the survey tool assembly 900 may occur through the inlet channel 965 and the bypass valve 970, as illustrated in
Any of the above-mentioned downhole electromechanical devices such as drilling tools, directional tools, sensor package, cementing gear, and the like may be controlled or actuated by string rotation; mud pump cycling, wireline electric signal, wired casing signal, or combinations thereof. Controlling and/or actuating by string rotation may involve using a number of start/stop cycles and/or varying rpm. Controlling and/or actuating by mud pump cycling may involve using a number of start/stops of the flow rate and/or varying the flow rate.
In one embodiment, the present invention provides a method for directing a trajectory of a lined wellbore comprising providing a drilling assembly comprising a wellbore lining conduit and an earth removal member; directionally biasing the drilling assembly while operating the earth removal member and lowering the wellbore lining conduit into the earth; and leaving the wellbore lining conduit in a wellbore created by the biasing, operating and lowering. In one aspect, directionally biasing the drilling assembly comprises urging fluid through a non-axis-symmetric orifice arrangement of the drilling assembly. In one embodiment, the non-axis-symmetric orifice arrangement is disposed on the earth removal member. In another aspect, directionally biasing comprises urging the drilling assembly against a non-axis-symmetric pad arrangement included thereon. In one embodiment, the non-axisymmetric pad arrangement is disposed on the wellbore lining conduit.
In an additional embodiment, the present invention provides a method for directing a trajectory of a lined wellbore comprising providing a drilling assembly comprising a wellbore lining conduit and an earth removal member; directionally biasing the drilling assembly while operating the earth removal member and lowering the wellbore lining conduit into the earth; and leaving the wellbore lining conduit in a wellbore created by the biasing, operating and lowering. In one embodiment, the method further comprises a second wellbore lining conduit having a portion disposed substantially co-axially within the wellbore lining conduit.
In an additional embodiment, the present invention provides a method for directing a trajectory of a lined wellbore comprising providing a drilling assembly comprising a wellbore lining conduit and an earth removal member; directionally biasing the drilling assembly while operating the earth removal member and lowering the wellbore lining conduit into the earth; and leaving the wellbore lining conduit in a wellbore created by the biasing, operating and lowering, the drilling assembly further comprising a motor having a rotating shaft, the rotating shaft having a fluid passage therethrough. In an additional embodiment, the present invention provides a method for directing a trajectory of a lined wellbore comprising providing a drilling assembly comprising a wellbore lining conduit and an earth removal member; directionally biasing the drilling assembly while operating the earth removal member and lowering the wellbore lining conduit into the earth; and leaving the wellbore lining conduit in a wellbore created by the biasing, operating and lowering, wherein a latch member operatively connects the earth removal member to the wellbore lining conduit.
In one embodiment, the present invention provides an apparatus for drilling a well, comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In one aspect, the divert assembly comprises a closing sleeve having one or more ports, the closing sleeve disposed in the shaft. In another aspect, the divert assembly comprises a rupture disk disposed to block fluid flow to the passageway in the shaft.
Another embodiment of the present invention provides an apparatus for drilling a well, comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In one aspect, the motor operating system comprises a hydraulic system, while in another aspect, the motor operating system comprises a system selected from a turbine system and a stator system.
An additional embodiment of the present invention provides an apparatus for drilling a well, comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a drill shoe rotatably connectable to a casing, the drill shoe comprising a rotatable drill face and a spindle connected to the shaft. In one aspect, the drill shoe includes a fluid connection to the passageway in the shaft. In another aspect, the drill shoe includes a shut-off mechanism for stopping fluid flow through the fluid connection.
In one embodiment, the present invention provides an apparatus for drilling a well, comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a casing latch attached to the motor system housing, the casing latch connected to releasably secure the apparatus to an internal surface of a casing. In one aspect, the casing comprises a nozzle biased in a direction for directionally drilling the casing. In another aspect, the casing comprises a stabilizer proximate to a midpoint of the casing for directionally drilling the casing. In yet another aspect, the casing latch includes a fluid passage connected to the passageway in the shaft. In yet another aspect, the apparatus further comprises a guide assembly connected to the casing latch, the guide assembly having a cone portion and a tubular portion. In one aspect, the guide assembly includes one or more seats for receiving a device selected from an inter string and an orientation device.
Another embodiment of the present invention provides an apparatus for drilling a well, comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft, wherein the motor system housing includes an enlargement portion for expanding a casing size.
An additional embodiment of the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a drill face operably connected to shaft of the motor system. In one aspect, the apparatus further comprises a latch for releasably latching onto the casing, the latch fixedly connected to the motor system.
An additional embodiment of the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a drill face operably connected to shaft of the motor system, wherein the divert assembly comprises a closing sleeve having one or more ports, the closing sleeve disposed in the shaft. A further additional embodiment of the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a drill face operably connected to shaft of the motor system, wherein the divert assembly comprises a rupture disk disposed to block fluid flow to the passageway in the shaft.
An additional embodiment of the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a drill face operably connected to shaft of the motor system, wherein the motor operating system comprises a hydraulic system. A further additional embodiment provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; and a drill face operably connected to shaft of the motor system, wherein the motor operating system comprises a system selected from a turbine system and a stator system.
In one embodiment, the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; a drill face operably connected to shaft of the motor system; and a drill shoe rotatably connectable to the casing, the drill shoe having the drill face and a spindle connected to the shaft. In one aspect, the drill shoe includes a fluid connection to the passageway in the shaft. In a further aspect, the drill shoe includes a shut off mechanism for stopping fluid flow through the fluid connection.
In one embodiment, the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; a drill face operably connected to shaft of the motor system; and a casing latch attached to the motor system housing, the casing latch connected to releasably secure the apparatus to an internal surface of the casing. In one aspect, the casing latch includes a fluid passage connected to the passageway in the shaft.
In another embodiment, the present invention provides an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; a drill face operably connected to shaft of the motor system; a casing latch attached to the motor system housing, the casing latch connected to releasably secure the apparatus to an internal surface of the casing; and a guide assembly connected to the casing latch, the guide assembly having a cone portion and a tubular portion. In one aspect, the guide assembly includes one or more seats for receiving a device selected from an inter string and an orientation device.
The present invention provides in yet another embodiment an apparatus for drilling with casing, comprising a casing; a motor system retrievably disposed in the casing, the motor system comprising a motor operating system disposed in a motor system housing; a shaft operatively connected to the motor operating system, the shaft having a passageway; a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft; a drill face operably connected to shaft of the motor system, wherein the motor system housing includes an enlargement portion for expanding a casing size.
Another embodiment of the present invention includes a method for drilling and completing a well, comprising pumping drill mud to a motor system disposed in a casing; rotating a drill face connected to the motor system; diverting fluid flow to a passageway through the motor system; and pumping cement through the passageway to the drill face. In one aspect, the method further comprises releasably latching the motor system to the casing utilizing a casing latch.
A further embodiment of the present invention includes a method for drilling and completing a well, comprising pumping drill mud to a motor system disposed in a casing; rotating a drill face connected to the motor system; diverting fluid flow to a passageway through the motor system; and pumping cement through the passageway to the drill face, wherein the drill mud and the cement are pumped utilizing an inter string. In another embodiment, the present invention includes Another embodiment of the present invention includes a method for drilling and completing a well, comprising pumping drill mud to a motor system disposed in a casing; rotating a drill face connected to the motor system; diverting fluid flow to a passageway through the motor system; pumping cement through the passageway to the drill face; and retrieving the motor system from the casing.
Another embodiment of the present invention includes a method for drilling and completing a well, comprising pumping drill mud to a motor system disposed in a casing; rotating a drill face connected to the motor system; diverting fluid flow to a passageway through the motor system; pumping cement through the passageway to the drill face; and expanding the casing utilizing an enlarged portion of a housing for the motor system.
In a further embodiment, the present invention includes a method of initiating and continuing a path of a wellbore, comprising providing a first casing having a first earth removal member operatively disposed at a lower end thereof; penetrating a formation with the first casing to form the wellbore; selectively altering a trajectory of the wellbore while penetrating the formation of the first casing; flowing drilling fluid to a motor system disposed in a second casing, the second casing being releasably attached to an inner diameter of the first casing and having a second earth removal member; rotating the second earth removal member with the motor system; and selectively altering the trajectory of the second casing as it continues into the formation. In one aspect, the trajectory of the second casing is altered more than the trajectory of the first casing.
The present invention further includes in one embodiment a method of altering a path of a casing into a formation, comprising providing an outer casing with a deflector releasably attached to its lower end; penetrating the formation with the deflector; releasing the releasable attachment; deflecting the path of the outer casing in the formation by moving the casing string along the deflector; releasing an inner casing from a releasable attachment to the outer casing; and flowing drilling fluid to a motor system disposed within the inner casing to rotate an earth removal member operatively attached to the motor system while altering a trajectory of the inner casing drilling into the formation. In another embodiment, the present invention further includes an apparatus for deflecting a wellbore, comprising an outer casing with a member for deflecting the casing string preferentially in a direction; a first earth removal member operatively connected to a lower end of the outer casing; and an inner casing having a motor operating system disposed therein disposed within the outer casing and operatively attached thereto.
In a yet further embodiment, the present invention includes a method for preferentially directing a path of a casing to form a wellbore, comprising providing a second casing concentrically disposed within a first casing having a biasing member, the second casing having a motor system releasably attached therein; jetting the first casing having an earth removal member operatively connected thereto into a formation to a first depth while selectively altering the trajectory of the wellbore using the biasing member; releasing a releasable attachment between the first and second casing; providing drilling fluid to the motor system; and selectively altering a trajectory of the second casing while rotating an earth removal member operatively connected to a lower end of the motor system as the second casing continues into the formation. In one aspect, the biasing member includes a preferential jet for directing fluid flow asymmetrically through the first casing while jetting. In another aspect, the biasing member includes a stabilizing member disposed proximate to a midpoint of the first casing.
In an embodiment, the present invention includes a method for preferentially directing a path of a casing to form a wellbore, comprising providing a second casing concentrically disposed within a first casing having a biasing member, the second casing having a motor system releasably attached therein; jetting the first casing having an earth removal member operatively connected thereto into a formation to a first depth while selectively altering the trajectory of the wellbore using the biasing member; releasing a releasable attachment between the first and second casing; providing drilling fluid to the motor system; selectively altering a trajectory of the second casing while rotating an earth removal member operatively connected to a lower end of the motor system as the second casing continues into the formation; and diverting fluid flow to a passageway through the motor system. In one aspect, the method further comprises flowing a physically alterable bonding material through the passageway to the earth removal member.
An additional embodiment of the present invention includes a method for preferentially directing a path of a casing to form a wellbore, comprising providing a second casing concentrically disposed within a first casing having a biasing member, the second casing having a motor system releasably attached therein; jetting the first casing having an earth removal member operatively connected thereto into a formation to a first depth while selectively altering the trajectory of the wellbore using the biasing member; releasing a releasable attachment between the first and second casing; providing drilling fluid to the motor system; selectively altering a trajectory of the second casing while rotating an earth removal member operatively connected to a lower end of the motor system as the second casing continues into the formation; drilling the second casing to a second depth; and expanding the second casing. In one aspect, expanding the second casing is accomplished by retrieving the motor system from the second casing.
In another embodiment, the present invention includes a method for preferentially directing a path of a casing to form a wellbore, comprising providing a second casing concentrically disposed within a first casing having a biasing member, the second casing having a motor system releasably attached therein; jetting the first casing having an earth removal member operatively connected thereto into a formation to a first depth while selectively altering the trajectory of the wellbore using the biasing member; releasing a releasable attachment between the first and second casing; providing drilling fluid to the motor system; selectively altering a trajectory of the second casing while rotating an earth removal member operatively connected to a lower end of the motor system as the second casing continues into the formation; and retrieving the motor system from the second casing.
The present invention further includes, in one embodiment, a method for preferentially directing a path of a casing to form a wellbore, comprising providing a second casing concentrically disposed within a first casing having a biasing member, the second casing having a motor system releasably attached therein; jetting the first casing having an earth removal member operatively connected thereto into a formation to a first depth while selectively altering the trajectory of the wellbore using the biasing member; releasing a releasable attachment between the first and second casing; providing drilling fluid to the motor system; selectively altering a trajectory of the second casing while rotating an earth removal member operatively connected to a lower end of the motor system as the second casing continues into the formation; and selectively introducing a surveying tool into the motor operating system to selectively measure the trajectory of the wellbore. In one aspect, the surveying tool selectively measures the trajectory of the wellbore while drilling with the first or second casing.
In an embodiment, the present invention includes a method for preferentially directing a path of a casing to form a wellbore, comprising providing a second casing concentrically disposed within a first casing having a biasing member, the second casing having a motor system releasably attached therein; jetting the first casing having an earth removal member operatively connected thereto into a formation to a first depth while selectively altering the trajectory of the wellbore using the biasing member; releasing a releasable attachment between the first and second casing; providing drilling fluid to the motor system; and selectively altering a trajectory of the second casing while rotating an earth removal member operatively connected to a lower end of the motor system as the second casing continues into the formation; and measuring a trajectory of the wellbore while drilling with the first or second casing.
An embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing having upper and lower portions and an earth removal member operatively attached to its lower end; and at least one hole-opening blade disposed on the upper portion of the casing string for gravitationally bending the casing to alter a trajectory of the wellbore. The hole-opening blade comprises a concentric stabilizer in one aspect. In another aspect, the hole-opening blade is an eccentric stabilizer. An additional embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing having upper and lower portions and an earth removal member operatively attached to its lower end; at least one hole-opening blade disposed on the upper portion of the casing string for gravitationally bending the casing to alter a trajectory of the wellbore; and at least one angled perforation in the earth removal member for further altering the trajectory of the wellbore through asymmetric fluid flow through the perforation.
An embodiment of the present invention includes a method for deflecting a wellbore while drilling with casing, comprising providing a casing with a drilling member at a lower end thereof; penetrating a formation with the casing while selectively altering a trajectory of the casing; pumping drilling fluid to a motor system disposed in an additional casing disposed within the casing; rotating the additional casing with the motor system, the motor system having an earth removal member operatively attached to its lower end; and selectively altering a direction of additional casing to deflect the wellbore at a further trajectory. An additional embodiment includes a method of deflecting a wellbore while drilling with casing, comprising providing a casing with a drilling member at a lower end thereof; providing a deflecting member releasably attached to the drilling member; anchoring the deflecting member in the wellbore at a predetermined depth; and urging the drilling member along the deflector, thereby altering the direction of the wellbore.
A further embodiment of the present invention includes a method of deflecting a wellbore while drilling with casing, comprising providing a casing with a drilling member at a lower end thereof, the drilling member having at least one fluid path extending therefrom, the fluid path directed away from a longitudinal centerline of the string; and pumping fluid through the fluid path, thereby altering the direction of the wellbore. A further embodiment includes a method of deflecting a wellbore while drilling with casing, comprising forming a first, larger diameter wellbore; providing a second, lower, smaller diameter wellbore; and slanting a casing string to direct the lower end thereof away from the centerline of the wellbore, thereby altering the direction of the wellbore.
In another embodiment, the present invention includes a method of initiating and continuing a path of a wellbore, comprising providing a casing string and a cutting apparatus disposed at a lower portion of the casing string; penetrating a formation with the casing string to form the wellbore; and selectively altering the trajectory of the casing string as it continues into the formation. In one aspect, selectively altering the trajectory of the casing string comprises selectively jetting fluid to create an asymmetric flow pattern through a lower portion of the cutting apparatus. In another aspect, selectively altering the trajectory of the casing string comprises selectively diverting fluid flow out of a portion of the casing string. In one embodiment, selectively diverting fluid flow forms a profile in a portion of the formation through which the casing string continues.
An embodiment of the present invention includes a method of initiating and continuing a path of a wellbore, comprising providing a casing string and a cutting apparatus disposed at a lower portion of the casing string; penetrating a formation with the casing string to form the wellbore; and selectively altering the trajectory of the casing string as it continues into the formation, wherein selectively altering the trajectory of the casing string comprises laterally moving the casing string through an enlarged inner diameter of an upper portion of the wellbore. Another embodiment includes the present invention includes a method of initiating and continuing a path of a wellbore, comprising providing a casing string and a cutting apparatus disposed at a lower portion of the casing string; penetrating a formation with the casing string to form the wellbore; selectively altering the trajectory of the casing string as it continues into the formation; and surveying the path of the wellbore while selectively altering the trajectory of the casing string.
A further embodiment provides the present invention includes a method of initiating and continuing a path of a wellbore, comprising providing a casing string and a cutting apparatus disposed at a lower portion of the casing string; penetrating a formation with the casing string to form the wellbore; selectively altering the trajectory of the casing string as it continues into the formation; and introducing at least one additional casing string into the casing string. In an embodiment, the present invention includes a method of initiating and continuing a path of a wellbore, comprising providing a casing string and a cutting apparatus disposed at a lower portion of the casing string; penetrating a formation with the casing string to form the wellbore; and selectively altering the trajectory of the casing string as it continues into the formation, wherein penetrating the formation with the casing includes jetting fluid through at least one nozzle disposed in the cutting apparatus, the at least one nozzle having an extended bore which is adjustable to vary the penetration rate of the casing into the formation.
An embodiment of the present invention includes a method of altering a path of a casing string in a formation, comprising providing a casing string with a deflector releasably attached to its lower end; penetrating the formation with the deflector; releasing the releasable attachment; and deflecting the path of the casing string in the formation by moving the casing string along the deflector. In one aspect, the deflector comprises an inclined wedge.
An additional embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing string with means for deflecting the casing string preferentially in a direction; and a first cutting apparatus disposed at a lower portion of the casing string. In one embodiment, means for deflecting the casing string preferentially in the direction comprises an inclined wedge releasably attached to a lower portion of the cutting apparatus. In another embodiment, means for deflecting the casing string preferentially in the direction comprises an angled perforation through the lower portion of the casing string for receiving a fluid. In yet another embodiment, means for deflecting the casing string preferentially in the direction further comprises a bent portion in the casing string for deflecting the casing string preferentially in a direction. In another embodiment, means for deflecting the casing string preferentially in the direction comprises a second cutting apparatus larger in diameter than the first cutting apparatus disposed on a portion of the casing string above the first cutting apparatus.
An embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing string with means for deflecting the casing string preferentially in a direction; a first cutting apparatus disposed at a lower portion of the casing string; and a landing seat for securing a survey tool therein. In another embodiment, the present invention includes an apparatus for deflecting a wellbore, comprising a casing string with means for deflecting the casing string preferentially in a direction; and a first cutting apparatus disposed at a lower portion of the casing string, wherein the casing string comprises a lower casing string and an upper casing string, and wherein means for deflecting the casing string preferentially in the direction comprises a second cutting apparatus which connects the lower casing string to the upper casing string and is larger in diameter than the second cutting apparatus.
Another embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing string with means for deflecting the casing string preferentially in a direction; a first cutting apparatus disposed at a lower portion of the casing string; and a drilling apparatus releasably connected to an inner diameter of the casing string with a second cutting apparatus disposed on the drilling apparatus below the releasable connection. In one aspect, the second cutting apparatus comprises a cutting structure disposed on a portion facing the releasable connection.
An embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing string with means for deflecting the casing string preferentially in a direction; and a first cutting apparatus disposed at a lower portion of the casing string, wherein the first cutting apparatus includes at least one nozzle extending therethrough, the at least one nozzle having an extended straight bore extending longitudinally therethrough.
An embodiment of the present invention includes an apparatus for deflecting a wellbore, comprising a casing string with means for deflecting the casing string preferentially in a direction; and a first cutting apparatus disposed at a lower portion of the casing string, wherein the first cutting apparatus includes at least one nozzle extending therethrough, the at least one nozzle having an extended straight bore extending longitudinally therethrough. In one embodiment, the at least one nozzle is drillable or made of a soft material such as copper. In another embodiment, the at least one nozzle comprises a thin coating of a hard material, the hard material having a hardness greater than a hardness of a soft material. The hard material may be ceramic or tungsten carbide. The remainder of the at least one nozzle may comprise a soft material such as copper.
In another embodiment, the first cutting apparatus includes at least one nozzle extending therethrough, the at least one nozzle being drillable and having a profiled sleeve coating of a hard material. In another embodiment, the first cutting apparatus includes at least one drillable nozzle extending therethrough, the at least one nozzle comprising a hard material having stressed portions therein for increasing breakability of the at least one nozzle when drilled therethrough.
In another embodiment, the stressed portions include a plurality of stressed, longitudinal notches in the at least one nozzle. In another embodiment still, a sealing material is disposed in the plurality of stressed notches.
In another aspect, the present invention provides a nozzle assembly usable within a tool body while jetting a casing into a formation. The nozzle assembly includes soft, drillable material forming a nozzle retainer and a thin sleeve of a hard material disposed within the nozzle retainer, the hard material forming an longitudinal bore extending past the exit and entry points of a fluid flow path through a hole through the tool body, the hard material having a hardness greater than a hardness of the soft material. In one embodiment, the soft material is copper. In another embodiment, the hard material is ceramic. In another embodiment still, the thin sleeve position is adjustable relative to the nozzle retainer.
In another aspect, the present invention provides a method for preferentially directing a path of a casing string to form a wellbore. The method includes jetting the casing string with a cutting structure connected thereto into a formation; and selectively directing the casing string in a direction as the casing string continues into the formation. In one embodiment, selectively directing the casing string in the direction comprises using the casing string to create an annular space in an upper portion of the wellbore and laterally directing an upper portion of the casing string through the annular space. In another embodiment, selectively directing the casing string comprises integrating arcs in the casing string to urge the casing string to form the path in the wellbore while directing fluid asymmetrically out of the cutting structure. In another embodiment, the casing string comprises a tubular body with an inclined wedge attached to its lower portion, and wherein selectively directing the casing string comprises directing the path of the wellbore by obstructing an axial path of the tubular body by the inclined wedge.
In another aspect, the present invention provides an apparatus for deflecting a wellbore. The apparatus includes a casing string having upper and lower portions and at least one hole-opening blade disposed on the upper portion of the casing string. In one embodiment, the apparatus also includes a cutting structure disposed on the lower portion of the casing string. In another embodiment, the apparatus further includes a tubular body releasably connected to an inner diameter of the casing string, wherein the tubular body has a cutting apparatus disposed at its lower end comprising a cutting structure located on upper and lower portions thereof.
In another aspect, the present invention provides a method for deflecting a wellbore while drilling with casing. The method includes providing a casing string with a drilling member at a lower end thereof; penetrating a formation with the casing string; and selectively altering a direction of the lower end to deflect the wellbore.
In another aspect, the present invention provides an assembly for drilling with casing. The assembly includes a casing latch for securing the assembly to a portion of casing; a bit attached to a bottom portion of the assembly; a biasing member for providing the bit with a desired deviation from a center line of the wellbore; and at least one adjustable stabilizer. In one embodiment, the bit is an expandable bit. In another embodiment, the stabilizer has one or more support members adapted to be placed in a first position for running through the portion of casing and a second position for engaging an inner wall of the wellbore. In another embodiment still, the stabilizer is adjustable to at least a third position, wherein an outer diameter of the stabilizer in the third position is less than the outer diameter of the stabilizer in the second position. In yet another embodiment, assembly includes a flexible collar disposed between the bit and the casing latch. In another embodiment still, the biasing member is a bent housing of a downhole motor adapted to drive the bit. In a further embodiment, the assembly includes a measurement tool that is adapted to measure a trajectory of the wellbore and communicate the measured trajectory to the wellbore surface. In another embodiment, the assembly includes at least one additional adjustable stabilizer. The bit may be a pilot bit. The bit may also include an underreamer.
In another aspect, the present invention provides a drilling assembly for creating a wellbore, the drilling assembly having a casing portion; a bit assembly disposed on a bottom portion of the drilling assembly, the bit assembly adapted to be expanded from a first diameter to a second diameter; and at least one stabilizer adapted to be adjusted from a first position to at least a second position. In one embodiment, the casing portion is expandable. In another embodiment, the bit assembly comprises an expandable bit. In another embodiment still, the drilling assembly further comprises a biasing member for providing the bit with a desired deviation from a center line of the wellbore. In yet another embodiment, the assembly includes a biasing member for providing the bit assembly with a desired deviation from a center line of the wellbore. In a further embodiment, the assembly includes a downhole drilling motor adapted to rotate the bit. In another embodiment, the assembly includes a flexible collar disposed between the bit assembly and a bottom end of the casing portion. In another embodiment still, the assembly also includes a measurement tool adapted to measure a trajectory of the wellbore and communicate the measured trajectory to the wellbore surface.
In one aspect, the present invention provides a method for drilling with casing. The method includes lowering a drilling assembly down a wellbore through casing, wherein the drilling assembly comprises an adjustable stabilizer and one or more drilling elements. The method also includes adjusting one or more support members of the stabilizer to increase a diameter of the stabilizer and operating the drilling assembly to extend a portion of the wellbore below the casing, wherein the extended portion having a diameter greater than an outer diameter of the casing. In one embodiment, the drilling elements may include an expandable bit for expanding the expandable bit to have a larger outer diameter than the casing.
In another embodiment, the method may include measuring a trajectory of the wellbore, and in response to the measured trajectory, making one or more adjustments from a surface of the wellbore. The adjustments may involve adjusting the support members of the stabilizer or adjusting a weight applied to the bit. The method may also include sensing a geophysical parameter.
In another embodiment, the method may include partially raising the drilling assembly through the casing; advancing the casing into the extended portion of the wellbore; and raising the drilling assembly through the casing to a surface of the wellbore.
In another aspect, the present invention provides an apparatus for drilling a wellbore in an earth formation. The apparatus includes a drill string having a longitudinal bore therethrough and a drilling assembly connected at the lower end of the drill string. Preferably, the drilling assembly is selected to be operable to form a borehole and at least in part to be retrievable through the longitudinal bore of the drill string. The apparatus may also include a directional borehole drilling assembly connected to the drill string and including biasing means for applying a force to the drilling assembly to drive it laterally relative to the wellbore and at least one adjustable stabilizer, the adjustable stabilizer retrievable through the longitudinal bore of the drill string. In one embodiment, the adjustable stabilizer is positioned above the biasing means of the directional borehole drilling assembly. In another embodiment, the drilling assembly comprises an expandable bit selected to be operable to form a borehole having a diameter greater than an outer diameter of the drill string and to be retrievable through the longitudinal bore of the drill string.
In another aspect, the present invention provides a method for directionally drilling a well with a casing as an elongated tubular drill string and a drilling assembly retrievable from the lower distal end of the drill string without withdrawing the drill string from a wellbore being formed by the drilling assembly. The method includes providing the casing as the drill string; a directional borehole drilling assembly connected to the drill string and including biasing means for applying a force to the drilling assembly to drive it laterally relative to the wellbore; and providing an adjustable stabilizer to support the directional borehole drilling assembly. The method also includes connecting the drilling assembly to the distal end of the drill string and inserting the drill string, the directional borehole drilling assembly, and the drilling assembly into the wellbore. The method further includes adjusting the adjustable stabilizer; forming a wellbore having a diameter greater than the diameter of the drill string; and operating the biasing means to drive the drilling assembly laterally relative to the wellbore. The method further includes removing at least a portion of the drilling assembly from the distal end of the drill string; removing the at least a portion of the drilling assembly out of the wellbore through the drill string without removing the drill string from the wellbore; and leaving the drill string in the wellbore. In one embodiment, the one or more support members is adjusted to change a diameter of the stabilizer. In another embodiment, prior to removing at least a portion of the drilling assembly from the distal end of the drill string, the method further includes partially raising at least a portion of the drilling assembly through the drill string and advancing the drill string within the wellbore.
In another aspect, the present invention provides an assembly for drilling with casing. The assembly includes a casing latch for securing the assembly to a portion of casing and a cutting structure attached to a bottom portion of the assembly. The assembly also includes a biasing member for providing the cutting structure with a desired deviation from a centerline of the wellbore, wherein biasing force for providing the cutting structure with the desired deviation is provided substantially by the casing. In one embodiment, the biasing member is an eccentric bias pad disposed on an outer diameter of the casing. The eccentric bias pad may alter the centerline of the casing relative to the borehole centerline in an opposite direction from the side of the casing on which the eccentric bias pad is disposed. In another embodiment, the biasing member comprises a bent motor housing within the casing. The assembly may also include a concentric stabilizer disposed around a lower end of the casing absorbs a majority of the biasing force. In another embodiment still, the casing latch is an orienting latch. In yet another embodiment, the assembly includes at least one of a measuring while drilling tool and a resistivity tool. In yet another embodiment, the cutting structure is expandable. In yet another embodiment, the assembly is retrievable from the casing.
In another aspect, the present invention provides a method of drilling with casing. The method includes providing a casing having an assembly releasably connected therein, the assembly comprising an earth removal member at its lower end and a biasing member. The biasing member deflects the earth removal member to a desired angle with respect to the centerline of the wellbore and to place a biasing force on the casing. In one embodiment, the method also includes sensing a geophysical parameter.
In another aspect, the present invention provides a method of forming a wellbore using a casing equipped with a cutting apparatus. The method includes positioning an orienting member in the casing, the orienting member having a predetermined orientation relative to the cutting apparatus; and positioning a survey tool with respect to the orienting member, such that an orientation of the survey tool in the casing is known. In one embodiment, the orienting member includes at least one flow aperture therethrough, and the survey tool includes at least one flow aperture therethrough. The orienting member provides an additional downhole functionality such as receiving a cementing tool therein or providing a stage tool integral therewith. In one embodiment, the orienting member may include a slot. In another embodiment, the orienting member may include a mule shoe profile and the survey tool includes a mating mule shoe profile receivable against the mule shoe profile of the landing shoe. The mule shoe profiles of the survey tool and the orienting member provide, upon mating of the mule shoe profiles, alignment between the landing shoe and the survey tool. In another embodiment, the orienting member includes a tubular element having a slot therein.
In another embodiment still, the casing comprises a float shoe and the orienting member is disposed in the float shoe. In another embodiment, the survey tool is positioned by landing the survey tool in the orienting member. In another embodiment still, the method further includes acquiring information relating a direction of the cutting apparatus. The method may also include sending the information to a receiving apparatus and steering the cutting apparatus in response to the information acquired. In another embodiment, the cutting apparatus includes a jetting assembly and/or a drilling bit. In yet another embodiment, the method also includes removing the survey tool before drilling is continued.
In another aspect, the present invention provides an apparatus for surveying a well wherein a drill string formed of a casing having a cutting apparatus. The apparatus includes an alignment member located in the drill string and a survey tool receivable in said alignment member and alignable thereby to a desired orientation in the drill string. In one embodiment, the alignment member includes a shoe having a profile thereon, the profile indexed rotationally with respect to the circumference of the drill string. The survey tool includes an alignment element interactive with the shoe upon locating of the survey tool in the shoe to provide a known alignment of the survey tool with the drill string. In another embodiment, the survey tool alignment element includes a profile matable with the profile of the alignment member. In yet another embodiment, the alignment member further includes a slot; the survey tool includes a generally cylindrical body having an alignment lug projecting therefrom; and the lug is positionable in the slot when the survey tool is disposed in the alignment member to provide a known orientation of the survey tool with the drill string.
In another embodiment still, the survey tool includes a generally hollow interior and an open end positionable in said alignment member, and at least one aperture extending through the body of said survey tool to communicate fluids from the casing to the hollow interior. The alignment member includes an aperture extending therethrough to communicate fluids from a region above the alignment member to a region below the alignment member, the alignment member otherwise blocking off the communication of fluids through the drill string therepast; and whereby upon placement of the survey tool in the alignment member for the alignment thereof, fluids may pass through the aperture, and thus through the hollow interior of the survey tool and through the alignment member. In another embodiment, the survey tool contains a survey apparatus located therein in a position so as not to interfere with fluid flow therethrough; and the survey apparatus may be operated to obtain borehole or formation information as fluid is flowing therethrough. In another embodiment, a drill shoe having a drill motor and a jetting apparatus is positioned on the end of the drill string, and the survey apparatus steers the drill shoe as the drill shoe penetrates an earth formation.
In yet another embodiment, the alignment member includes a stage tool and may further include a float tool to receive a cement shoe thereon.
In another aspect, the present invention provides an apparatus for drilling with casing. The apparatus includes casing having a drilling member disposed at a lower portion thereof and a pivoting member coupling the drilling member to the casing, wherein the drilling member may be pivoted away from a centerline of the casing for directional drilling. In one embodiment, apparatus further includes a drilling motor, wherein the pivoting member is coupled to the drilling motor.
In another aspect, the present invention provides a survey tool for use while drilling with casing. The survey tool includes a body having a bore therethrough and one or more measurement devices. The survey tool also includes an inlet for fluid communication between the casing and the bore of the body and a bypass valve for diverting fluid in the casing from the inlet. In one embodiment, the bypass valve is in a closed position when the fluid is at a lower fluid flow rate, while a higher flow rate places the bypass valve in an open position.
In another aspect, the present invention provides a method of collecting information while drilling with casing. The method includes providing a measurement tool in a casing, the measurement tool having a first inlet and a second inlet. The method also includes flowing fluid through a first channel to actuate the measurement tool and collecting information on a condition in the wellbore. The method also includes increasing fluid flow in the casing and flowing fluid through the second channel to continue drilling.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application is a continuation of U.S. patent application Ser. No. 11/932,495, filed on Oct. 31, 2007, now U.S. Pat. No. 8,127,868, which is a continuation of U.S. patent application Ser. No. 10/772,217, filed on Feb. 2, 2004, now U.S. Pat. No. 7,334,650, which claims benefit of U.S. Provisional Patent Application Ser. No. 60/452,202, filed on Mar. 5, 2003, and U.S. Provisional Patent Application Ser. No. 60/444,088, filed on Jan. 31, 2003, which applications and patents are herein incorporated by reference in their entirety.
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| Number | Date | Country | |
|---|---|---|---|
| 20120168228 A1 | Jul 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60444088 | Jan 2003 | US | |
| 60452202 | Mar 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11932495 | Oct 2007 | US |
| Child | 13412297 | US | |
| Parent | 10772217 | Feb 2004 | US |
| Child | 11932495 | US |
