Patent Grant
7413020
1. Field of the Invention
Embodiments of the present invention generally relate to drilling and completion of oil and gas wells. More specifically, embodiments of the present invention relate to methods and apparatus for forming a wellbore by drilling with casing. Embodiments of the present invention generally relate, more particularly, to the construction of lateral wellbores.
2. Description of the Related Art
In the drilling of oil and gas wells, a wellbore is formed in a formation using a drill bit that is urged downwardly at a lower end of a drill string. After drilling a predetermined depth, the drill string and the drill bit are removed, and the wellbore is typically lined with a string of pipe called casing. The casing forms a major structural component of the wellbore and serves several important functions, such as preventing the formation wall from caving into the wellbore, isolating different zones in the formation, preventing the flow of fluids into the wellbore, and providing a means of maintaining control of fluids and pressure while drilling. Casing is available in a range of sizes and material grades, the choice of which is typically determined by a particular application.
The casing typically extends down the wellbore from the surface to a designated depth. Various downhole tools are often run through the casing to perform various operations downhole in the wellbore. Accordingly, the drift diameter of the casing dictates the types of downhole tools that may be run through the casing. Drift diameter generally refers to the inside diameter that the casing manufacturer guarantees per specifications. In other words, the drift diameter may be used (e.g., by a well planner) to determine what size tools may later be run through the casing.
For various production oriented reasons, it may be desirable to form a lateral (e.g., deviating from vertical) wellbore extending from a main (or “parent”) wellbore. For example, because a lateral wellbore typically penetrates a greater length of the reservoir, it may offer significant production improvement over a purely vertical main wellbore. Lateral wellbores extending from a cased main wellbore may be formed by removing a portion of the main wellbore casing to expose a portion of the formation. The lateral wellbore may then be formed by drilling out from the main wellbore through the exposed portion of the formation. Various well-known techniques are available to achieve the desired deviation from the main wellbore when drilling the lateral wellbore.
For the previously described reasons (e.g., support, isolation, etc.), it is also desirable to line a lateral wellbore with casing. However, in order to reach the lateral wellbore, casing used to line the lateral wellbore must pass through the main wellbore casing. Therefore, to run the casing into the lateral wellbore, the outer diameter of the casing used to line the lateral wellbore must be smaller than the inner diameter of the main wellbore casing. Accordingly, casing used to line conventional lateral wellbores has been limited to casing having inner diameters significantly smaller than the main wellbore casing. As a result of this smaller inner diameter, the types of downhole tools that may be run in the lateral wellbore are typically restricted, thereby limiting the types of operations that may be performed therein. Accordingly, what is needed is an improved method for forming a lateral wellbore lined with casing having an enlarged inner diameter relative to casing lining conventional lateral wellbores.
To drill within the wellbore to a predetermined depth in conventional well completion operations, the drill string is often rotated by a top drive or rotary table on a surface platform or rig, or by a downhole motor mounted towards the lower end of the drill string. After drilling to a predetermined depth, the drill string and drill bit are removed and a section of casing is lowered into the wellbore. An annular area is thus formed between the string of casing and the formation. The casing string is temporarily hung from the surface of the well. A cementing operation is then conducted in order to fill the annular area with cement. Using apparatus known in the art, the casing string is cemented into the wellbore by circulating cement into the annular area defined between the outer wall of the casing and the borehole. 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. In this respect, the well is drilled to a first designated depth with a drill bit on a drill string. The drill string is removed. A first string of casing or conductor pipe is then run into the wellbore and set in the drilled out portion of the wellbore, and cement is circulated into the annulus behind 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 then fixed, or “hung” off of the existing casing by the use of slips which utilize slip members and cones to wedgingly fix the new string of liner in the wellbore. The second casing string is then cemented. This process is typically repeated with additional casing strings until the well has been drilled to total 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, drilling with casing is a method sometimes used to place casing strings within the wellbore. This method involves attaching a cutting structure in the form of a drill bit to the same string of casing which will line the wellbore. Rather than running a drill bit on a smaller diameter drill string, the drill bit or drill shoe is run in at the end of the larger diameter of casing that will remain in the wellbore and be cemented therein. Drilling with casing is a desirable method of well completion because only one run-in of the working string into the wellbore is necessary to form and line the wellbore for each casing string.
Specifically, drilling with casing is typically accomplished by lowering and rotating a first casing string with a cutting structure attached thereto into a formation to form a portion of the wellbore at a first depth. During the lowering of the casing string, it is often necessary to circulate drilling fluid while drilling into the formation to form a path within the formation through which the casing string may travel. The first casing string is cemented into the formation. Next, a second casing string with a drill bit attached thereto is lowered and rotated into the formation while circulating fluid to form a portion of the wellbore at a second depth. The second casing string is hung off of the first casing string and cemented into the formation. This process can be repeated with additional casing strings until the wellbore extends to the desired depth.
Because the second casing string must travel through the first string of casing to reach the formation below the first casing string, the second casing string must have a smaller inner diameter than the second casing string. Historically, therefore, as more casing strings were set in the wellbore, the casing strings became progressively smaller in diameter in order to fit within the previous casing string. The drill bit for drilling to the next predetermined depth must thus become progressively smaller as the diameter of each casing string decreases in order to fit within the previous casing string. Therefore, multiple drill bits of different sizes are ordinarily necessary for drilling in well completion operations. Progressively decreasing the diameter of the casing strings with increasing depth within the wellbore limits the size of wellbore tools which are capable of being run into the wellbore. Furthermore, restricting the inner diameter of the casing strings limits the volume of hydrocarbon production which may flow to the surface from the formation.
Recently, methods and apparatus for expanding the diameter of casing strings within a wellbore have become feasible. When using expandable casing strings to line a wellbore, the well is drilled to a first designated depth with a drill bit on a drill string, then the drill string is removed. A first string of casing is set in the drilled out portion of the wellbore, and cement is circulated into the annulus behind the casing string. Next, the well is drilled to a second designated depth, and a second string of casing is run into the drilled out portion of the wellbore at a depth such that the upper portion of the second string of casing overlaps the lower portion of the first string of casing. Cement can be placed behind the second casing string and then the second casing string is expanded into contact with the existing first string of casing with an expander tool. This process is typically repeated with additional casing strings until the well has been drilled to total depth.
An advantage gained with using expander tools to expand expandable casing strings is the decreased annular space between the overlapping casing strings. Because the subsequent casing string is expanded into contact with the previous string of casing, the decrease in diameter of the wellbore is essentially the thickness of the subsequent casing string. However, even when using expandable technology, casing strings must still become progressively smaller in diameter in order to fit within the previous casing string.
Currently, monobore wells are being investigated to further limit the decrease in the inner diameter of the wellbore with increasing depth. Monobore wells would theoretically result when the wellbore is approximately the same diameter along its length or depth through the expansion of casing strings, causing the path for fluid between the surface and the wellbore to remain consistent along the length of the wellbore and regardless of the depth of the well. In a monobore well, tools could be more easily run into the wellbore because the size of the tools which may travel through the wellbore would not be limited to the constricted inner diameter of casing strings of decreasing inner diameters.
Theoretically, in the formation of a monobore well, a first casing string could be inserted into the wellbore and cemented therein. Thereafter, a second casing string of a smaller diameter than the first casing string could be inserted into the wellbore and expanded to approximately the same inner diameter as the first casing string. The casing strings may be connected together through a conventional hanger, or by expanding the inner diameter of the larger diameter first casing string, which is located above the second casing string, where the first and second casing strings overlap. Additional casing strings would be inserted into the wellbore and expanded, as described in relation to the first and second casing strings, until the wellbore extends to the desired depth.
With monobore well investigation, certain problems present. One problem relates to the expansion of the smaller casing string into the larger casing string to form the connection therebetween. Current methods of expanding casing strings in a wellbore to create a connection between casing strings requires the application of a radial force to the interior of the smaller casing string and expanding its diameter out until the larger casing string is itself pushed past its elastic limits. The result is a connection having an outer diameter greater than the original outer diameter of the larger casing string. While the increase in the outer diameter is small in comparison to the overall diameter, there are instances where expanding the diameter of the larger casing string is difficult or impossible. For example, in the completion of a monobore well, the upper casing string may be cemented into place before the next casing string is lowered into the well and its diameter expanded. Because the annular area between the outside of the larger casing string and the borehole therearound is filled with cured cement, the diameter of the larger casing string cannot expand past its original shape. Expansion of the required magnitude may also rupture the casing.
When hanging a casing string from another casing string, whether during a drilling operation or a drilling with casing operation, the casing string being hung may be set mechanically or hydraulically. A typical apparatus for setting a casing string in a well casing includes a liner hanger and a running tool. The running tool is provided with a valve seat obstruction which will allow fluid pressure to be developed to actuate the slips in order to set the liner hanger in the well casing. Once the liner hanger has been set, the running tool is rotated counterclockwise to unscrew the running tool from the liner hanger and the running tool is then removed.
One advantageous use for expandable tubulars is to hang one tubular within another. For example, the upper portion of a casing string can be expanded into contact with the inner wall of a casing in a wellbore. In this manner, the bulky and space-demanding slip assemblies and associated running tools can be eliminated. One problem with using expandable tubular technology used casing strings relates to cementing the casing strings within the wellbore. Cementing is performed by circulating uncured cement down the wellbore and back up an annulus between the exterior of the casing string being set and the wellbore therearound. In order for the cement to be circulated, a fluid path is necessary between the annulus and the wellbore. Hanging a casing string in a wellbore by circumferentially expanding its walls into the well casing obstructs the juncture and prevents circulation of fluids. To avoid this circulation problem, casing strings must usually be temporarily hung in a wellbore prior to cementing.
Therefore, a need exists for a method and apparatus for forming a substantially monobore well when drilling with casing. There is a further need for an apparatus and method for use when drilling with casing for forming a cased wellbore with an inner diameter which does not decrease with increasing depth within the wellbore. There is a yet further need for an apparatus and method for use in drilling with casing which involves running a casing string of smaller inner diameter into a formation and subsequently expanding a casing string of larger inner diameter to form a wellbore with substantially the same inner diameter along its length.
Moreover, there is a need for apparatus and methods that permit casing to be hung in a well and also leave a fluid path around the casing, at least temporarily. Additionally, there is a need for casing having a means for circulating fluids therearound even after the casing has been hung within the wellbore or previously installed casing.
Embodiments of the present invention generally relate to methods and apparatus for forming a substantially monobore well which does not decrease in diameter with increasing depth or length within the formation. Embodiments of the present invention further generally provide full bore lined lateral wellbores, and methods of making the same.
For one embodiment, a method of forming a full bore lined lateral wellbore is provided. The method generally includes forming a lateral wellbore extending from a main wellbore, wherein a diameter of the lateral wellbore is larger than an inner diameter of casing lining the main wellbore, running an expandable tubular element through the casing lining the main wellbore into the lateral wellbore, and expanding the tubular element within the lateral wellbore. The expanded tubular element may have an outer diameter larger than the drift diameter of the main wellbore lining. For some embodiments, the expanded tubular may have an inner diameter greater than the inner diameter of the main wellbore casing, providing a full-bore lined lateral. For some embodiments, the lateral wellbore may be formed and the expandable tubular element may be run concurrently in a single pass through the main wellbore, utilizing a drilling with lining operation.
For one embodiment, another method of forming a full bore lined lateral wellbore is provided. The method generally includes securing a diverter within a main wellbore lined with casing, forming a lateral wellbore with a drill bit guided by the diverter, expanding a diameter of at least a portion of the lateral wellbore, running an expandable tubular element, through the casing lining the main wellbore, into the lateral wellbore, and expanding the tubular element within the lateral wellbore, such that the expanded tubular element has an outer diameter larger than the inner diameter of the casing lining the main wellbore.
For one embodiment, a lateral wellbore extending from a main wellbore lined with casing is provided. At least a portion of the lateral wellbore is lined with casing, the casing having an outer diameter larger than the drift diameter of the main wellbore casing. For some embodiments, the lined portion of the lateral wellbore may extend to the main wellbore.
The present invention generally provides an apparatus and method for forming a cased wellbore which does not decrease in inner diameter with increasing depth while drilling with casing. More specifically, the present invention provides an apparatus and method for forming a cased wellbore of substantially the same inner diameter with increasing depth while drilling with casing. In one aspect, the apparatus includes a casing string, an earth removal member or cutting structure operatively attached to a lower end of the casing string, and a compressible member disposed at a lower end of the casing string. In another aspect, the apparatus includes a casing string with an enlarged inner diameter at its lower end, an earth removal member or cutting structure operatively attached to a lower end of the casing string, and a drillable portion disposed within the casing string.
In one aspect, the method includes drilling a wellbore using a first casing string with an earth removal member or cutting structure operatively disposed at its lower end, locating the first casing string within the wellbore, locating a portion of a second casing string adjacent to a portion of the first casing string with an enlarged inner diameter, and expanding the portion of the second casing string so that the portion of the second casing string has an inner diameter at least as large as a smallest inner diameter portion of the first casing string. In another aspect, the method includes drilling a wellbore using a first casing string with a cutting structure operatively disposed at its lower end and a compressible member disposed around the first casing string, locating the first casing string within the wellbore, locating a portion of a second casing string adjacent to the compressible member, and expanding the portion of the second casing string so that the portion of the second casing string has an inner diameter at least as large as a smallest inner diameter portion of the first casing string.
Providing a method and apparatus for drilling with casing to form a substantially monobore well increases the possible inner diameter of a cased wellbore formed by drilling with casing. As a consequence, flexibility in the tools which are capable of being run into the cased wellbore is increased. Furthermore, forming a substantially monobore well using drilling with casing technology allows a wellbore of substantially the same inner diameter along its length to be formed in less time compared to conventional drilling methods.
In one aspect, embodiments of the present invention generally provide a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth, expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore, leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing, flowing a fluid through the fluid path, and closing the fluid path. In another aspect, embodiments of the present invention provide a method of casing a wellbore, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore, the first casing having at least one bypass for circulating a fluid formed therein, expanding at least a portion of the first casing into frictional engagement with the wellbore to hang the first casing within the wellbore, circulating the fluid through the at least one bypass, and expanding the first casing to close the bypass.
In yet another aspect, embodiments of the present invention include an apparatus for use in drilling with casing, comprising a tubular string having a casing portion, an earth removal member operatively attached to its lower end, and at least one fluid bypass area located thereon, and an expansion tool disposed within the tubular string, the expansion tool capable of expanding a portion of the tubular string into a surrounding wellbore while leaving a flow path around an outer diameter of the tubular string to a surface of the wellbore.
So that the manner in which the above recited features of the present invention, and other features contemplated and claimed herein, are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof 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.
Embodiments of the present invention generally provide methods and apparatus for forming a lined wellbore which does not decrease in diameter with increasing depth or length within the formation. The wellbore may include only a main wellbore or may include the main wellbore and any number of lateral wellbores extending therefrom. In some embodiments, drilling with casing is utilized to form a substantially monobore well lined with the casing.
In one aspect, embodiments of the present invention provide improved lateral wellbores and apparatus and methods for forming the same. The lateral wellbores extend from a main wellbore and are at least partially lined with casing having an outer diameter larger than the drift diameter of casing used to line the main wellbore (at least the casing used to line the main wellbore above the lateral). For some embodiments, the inner diameter of the lateral wellbore casing may be larger than the inner diameter of the main wellbore casing. Such lateral wellbores may be referred to as full bore lined lateral wellbores. In either case, by providing a larger inner diameter than conventional lateral wellbores, a larger variety of tools may be run in the lateral wellbore.
The operations 100 begin, at step 102, by forming a main wellbore lined with casing. For example, as illustrated in
Advantages of forming the casing from expandable tubulars include an increase in the achievable inner diameter throughout the length of the main wellbore. In other words, conventional casing techniques require the use of sequential casing strings of increasingly smaller diameters, because each successive casing string must be run through the previous casing string. However, expandable tubulars may be run downhole in an unexpanded state having a sufficiently small outer diameter to pass through the inner diameter of previously expanded tubulars. Accordingly, casing formed of expandable tubulars need not suffer the successively smaller diameters associated with conventional casing, and may provide full bore access to the main wellbore, thereby potentially allowing a greater variety of downhole tools to be run in the main wellbore 202.
At step 104, a lateral wellbore extending from the main wellbore is formed, wherein the diameter of the lateral wellbore is larger than the inner diameter of the main wellbore casing 204. As illustrated in
As illustrated in
In order to be run through the casing 204, an earth removal member, preferably a drill bit (not shown), used to drill through the cement 212 must have an outer diameter less than the inner diameter of the casing 204. Accordingly, the lateral wellbore 214 drilled with the drill bit may initially have a diameter smaller than the inner diameter of the casing 204 and must, therefore, be expanded. As illustrated, the lateral wellbore 214 may be expanded using an expandable bit 218, underreamer, back reamer, or similar apparatus. An example of an expandable bit is disclosed in International Publication Number WO 01/81708. A1, which is incorporated by reference herein in its entirety. Similar to a conventional under-reamer, the expandable bit may include a set of blades that move between an open, extended position and a closed, retracted position. Generally, movement of the blades between the open and the closed position may be controlled through the use of hydraulic fluid flowing through the center of the expandable bit. For example, increasing the hydraulic pressure (i.e., by increasing the flow) may move the blades to the open position, while decreasing the hydraulic pressure may return the blades to the closed position.
Therefore, the blades may be placed in a closed (retracted) position giving the expandable bit 218 a smaller diameter than the inner diameter of the casing 204, allowing the expandable bit 218 to be run in the lateral wellbore 214. The blades may then be opened giving the expandable bit 218 a larger diameter, allowing at least a portion of the lateral wellbore 214 to be expanded to have a greater diameter than the inner diameter of the casing 204. After expanding the portion 216 of the lateral wellbore 214, the blades may be returned to the closed position and the expandable bit 218 may be removed through the lateral wellbore 214 and the casing 204 of the main wellbore 202. Cutting members disposed on the arms of the expandable bit 218 may be made of any suitable hard material, such as tungsten carbide or polycrystalline diamond (“PCD”).
At step 106, an expandable tubular lining is run into the lateral wellbore 214. At step 108, the tubular lining is expanded to have an inner diameter equal to or larger than the inner diameter of the main wellbore casing 204. For example, as illustrated in
Recalling that the term “drift diameter” generally refers to the inside diameter that the casing manufacturer guarantees per specifications, the specified drift diameter of the main wellbore casing 204 is typically at least slightly smaller than the actual inner diameter D1 to allow for manufacturing tolerances. As previously described, to ensure that the casing elements could be run through the main wellbore casing 204, the outer diameter of casing used to line conventional lateral wellbores was smaller than the drift diameter of the main wellbore casing 204. In contrast, once expanded, the tubular 220 may have an outer diameter greater than the drift diameter of the main wellbore casing 204. Of course, this larger outer diameter also results in a larger inner diameter.(assuming like casing thicknesses). For some embodiments, as illustrated in
As an example, a typical 9⅝-in. casing may have an 8.53-in. drift diameter. Accordingly, the lateral wellbore 214 may be initially formed by drilling through the cement 212 with an 8.50-in. diameter bit. Prior to running the expandable tubular 220, the lateral wellbore 214 may be expanded to have a diameter sufficiently large (e.g., approximately 9.63 in.) to allow the tubular 220 to expand to have an inner diameter greater than 8.53 in. Of course, actual dimensions will vary depending on the particular application.
Regardless of the actual dimensions, in contrast to conventional lateral wellbores lined with casing having a smaller inner diameter than the main wellbore lined within casing, the larger inner diameter of the lateral wellbore 214 may provide full bore access for the running of tools for various operations. For some applications, it may be desirable to leave the lateral wellbore 214 isolated from sections of the main wellbore 202 below a junction between the lateral wellbore 214 and the main wellbore 202 (the “lateral junction”). Alternatively, as illustrated in
As previously described with reference to
Decisions regarding how to form a lateral wellbore (e.g., using cement or a diverter) may be made based on application considerations. For example, forming the lateral wellbore 214 using the cementing technique illustrated in
As illustrated in
However, as illustrated in
Subsequently, as illustrated in
Referring again to
As illustrated in
Once the enlarged lateral wellbore 214 is formed, the expandable tubular element 220 may be expanded, as previously described. Prior to or after the expanding, one or more components of the BHA 240 may be retrieved from the lateral wellbore 214. For example, the BHA 240 may be detached from the tubular element 220 by unlatching the latch 242, the one or more expandable members 245 of the expandable stabilizer 244 may be retracted, and the expandable bit 218 may be retracted to retrieve the entire BHA 240. As an alternative, any or all of the components of the BHA 240 may be left in the lateral wellbore 214, for example if the costs associated with retrieval outweigh the costs of the equipment.
As illustrated in
Because of this risk, it may be desirable to have the option of cementing after expansion. For some embodiments, this option may be provided by forming the lateral wellbore 214 with a sufficiently large diameter. In other words, the diameter of the lateral wellbore 214 may be designed to accommodate cement 212 flowing freely to surround the tubular 220 even after expansion. Therefore, the expanding and cementing operations may be performed independently, and the risk of the cement setting prior to completion of the expansion operation may be eliminated.
Through the use of expandable tubulars, embodiments of the present invention provide lined lateral wellbores having an outer diameter greater than the drift diameter of casing lining the main wellbore from which they extend. For some embodiments, the inner diameter of the lateral wellbore casing may be equal to or larger than the inner diameter of the main wellbore casing, thus providing a full-bore lined lateral. Accordingly, downhole tools designed to be run through the main wellbore casing may also be run through the lateral wellbore casing, thus providing greater flexibility in operations performed within the lateral wellbore.
In another embodiment, a substantially monobore well, or at least a cased wellbore which does not increase in diameter with increasing depth or length of the wellbore, is formed in a formation regardless of whether a lateral wellbore is formed. A first casing string and a second casing string may comprise a section of casing or two or more sections of casing connected (preferably threadedly connected) to one another. In one aspect, the first casing string has an enlarged inner diameter into which a second casing string is expanded into so that the inner diameter of the second casing string is at least as large as the inner diameter of the first casing string. In another aspect, a first casing string includes at least one compressible member which may be compressed when a second casing string is expanded into the first casing string, thereby forming a wellbore where the inner diameter of the second casing string is at least as large as the inner diameter of the first casing string.
A lower portion of an inner diameter of the first casing string 310 has a cut-away portion 325 therein. The cut-away portion 325 of the first casing string 310 has a larger inner diameter than the remaining portion of the first casing string 310 disposed above the cut-away portion 325, so that the cut-away portion 325 is an undercut portion of the first casing string 310. The cut-away portion 325 provides a mating surface for an upper portion of a second casing string 810 (shown in
Disposed within the inner diameter of the first casing string 310 is a drillable cementing assembly 330 which facilitates the function of cementing an annular space 335 between the outer diameter of the first casing string 310 and the inner diameter of the wellbore 305. The cementing assembly 330, preferably a cement shoe assembly, comprises a longitudinal bore 323 running therethrough, providing a fluid flow path for cement and well fluids. A one-way valve, for example a check valve 350, is located within the longitudinal bore 323. The check valve 350 permits fluid entrance from the well surface through the check valve 350 and into the longitudinal bore 323, yet prevents fluid from passing from the wellbore 305 into a portion of the first casing string 310 above the check valve 350. A spring 351, as shown in
An annular area 321 adjacent to the check valve 350 and between the inner diameter of the first casing string 310 and the longitudinal bore 323 is filled with a drillable material, preferably cement, to stabilize the longitudinal bore 323. One or more upsets 352 (preferably a plurality of upsets 352) are disposed in the first casing string 310 to hold the cement in place and prevent axial movement thereof. Lining the longitudinal bore 323 between the check valve 350 and a lower end of the first casing string 310 is a tubular member 331. An annular area 332 between the tubular member 331 and the first casing string 310 is filled with an aggregate material such as sand. The purpose of the aggregate material is to support the tubular member 331.
Below the annular area 332 filled with aggregate material is a drillable portion 340. The drillable portion 340 is connected, preferably threadedly connected, to a lower end of the first casing string 310 so that a longitudinal bore 333 running through the drillable portion 340 is in line with the longitudinal bore 323. The drillable portion 340 is constructed of drillable material to support the aggregate material in the annular space 332 and has wear-resistant characteristics so that the material is not affected by hydraulic pressure characteristic of the wellbore 305 conditions. Preferably, the drillable portion 340 is formed of a solid material, and even more preferably, with a composite material such as fiberglass.
One or more grooves (not shown) may be disposed on an outer portion of the drillable material 340 around the perimeter of the drillable material 340 where the drillable material 340 meets the first casing string 310. The groove ensures that the drillable portion 340 falls away from the first casing string 310 as the second casing string 810 drills through the first casing string 310, as described below. Disposed in an upper portion of the drillable material 340 are one or more radially extending voids (not shown) formed in the composite material which extend from the first casing string 310 inward to terminate adjacent to the tubular member 331. The voids in the composite material ensure that the outermost portions of the drillable material 340 fall away from the first casing string 310 as the second casing string 810 drills through the first casing string 310.
An example of an expandable cutting structure 805 in the form of an expandable drill bit is disclosed in U.S. application Ser. No. 10/335,957 filed on Dec. 31, 2002, which is herein incorporated by reference in its entirety.
The expandable cutting structure 805 generally includes a set of blades 806, 807 which move between the open and closed position. Hydraulic fluid flowing through the expandable cutting structure 805 controls the movement of the blades 806, 807 between the open and closed position.
The expandable cutting structure 805 is preferably an expandable drill bit. A plurality of cutting members 808 is disposed on an outer portion of the blades 806, 807. The cutting members 808 are typically small and substantially spherical and may be made of tungsten carbide or polycrystalline diamond surfaces. The blades 806, 807 are constructed and arranged to permit the cutting members 808 to contact and drill into the earth when the blades 806, 807 are expanded outward and not ream the wellbore 305 or surrounding casing string 310 when the blades 806, 807 are collapsed inward.
Generally, one or more nozzles 385 of the expandable cutting structure 805 are in fluid communication with a longitudinal bore through the second casing string 810. The nozzles 385 allow jetting of the drilling fluid during the drilling operation through the first casing string 310 to remove any cutting build-up which may gather in front of the blades 806, 807. The nozzles 385 also permit jetting of the drilling fluid during the drilling operation through the formation 320 below the first casing string 310 to form a path for the second casing string 810 through the formation 320. Furthermore, the nozzles 385 are used to create a hydraulic pressure differential within the bore through the second casing string 810 to cause the blades 806, 807 of the expandable cutting structure 805 to expand outward, as described in U.S. application Ser. No. 10/335,957, incorporated by reference above.
In
An attenuator 505 is disposed on or in the first casing string 610. In the embodiment shown, the attenuator 505 is disposed circumferentially around an outer diameter of a lower end of the first casing string 610. The attenuator 505 is preferably compressible due to radial force, but capable of withstanding hydrostatic pressure within a wellbore 605. Cement or another comparable physically alterable bonding material must be capable of bonding to the attenuator 505. Preferably, the attenuator 505 is constructed of compressible aluminum.
The attenuator 505 includes a wall 510 located a distance radially from the outer diameter of the first casing string 610. The wall 510 is connected to the first casing string 610 by one or more webs 515, preferably a plurality of webs 515, extending radially therefrom. In between the plurality of webs 515 is at least one void area 520. The wall 510 and the plurality of webs 515 prevent cement and other fluids from entering the void areas 520, so that the webs 515 compress into the void areas 520 upon radial force exerted by an expander tool 400 (see
In an alternate embodiment, the attenuator 505 may be constructed of a compressible material with voids disposed therein. In this embodiment, because the material is inherently compressible, the webs 515 and the void areas 520 are not necessary. Preferably in this embodiment, the attenuator 505 is constructed of a porous material which is compressible due to radial force, but withstands hydrostatic pressure. More preferably, the attenuator 505 is constructed of styrofoam.
In the operation of the first embodiment illustrated in
After the first casing string 310 is drilled to the desired depth within the formation 320, the flow of drilling fluid is halted. To determine when the first casing string 310 has reached the desired depth within the formation 320, logging-while-drilling or measuring-while-drilling may be utilized, as is known by those skilled in the art. Specifically, one or more logging and/or measuring tools may be employed within or on the first casing string 310 to determine by measuring one or more geophysical parameters in the formation 320 whether the first casing string 310 is proximate to the desired location. Exemplary geophysical parameters which may be sensed within the formation 320 include but are not limited to resistivity of the formation 320, pressure, and temperature.
A physically alterable bonding material, preferably a setting fluid such as cement, may then be introduced into the first casing string 310. A volume of cement is introduced into the first casing string 310 which is sufficient to fill at least a portion of the annular space 335 between the first casing string 310 and the wellbore 305, thus cementing the first casing string 310 into the formation 320. The cement flows through the first casing string 310, through the check valve 350, through the longitudinal bore 323, through the perforations 316 in the cutting structure 315, and up through the annular space 335. The check valve 350 prevents the cement from flowing back up through the casing string 310 to the surface, thus forcing the cement flow out into the formation 320. After the cement is pumped into the wellbore 305, drilling fluid may optionally be pumped into the first casing string 310 to ensure that most of the cement exits the lower end of the cutting structure 315.
Once the first casing string 310 has been set within the formation 320 when the cement cures, the second casing string 810 is utilized to drill through the drillable cementing assembly 330 within the first casing string 310. The outer diameter of the second casing string 810 is necessarily smaller than the inner diameter of the first casing string 310, so that the second casing string 810 fits within the first casing string 310. Similarly, the largest portion of the expandable cutting structure 805 must be smaller than the inner diameter of the first casing string 310 while the expandable cutting structure 805 is in the retracted position.
The second casing string 810 is lowered (e.g., by the draw works) into the inner diameter of the first casing string 310 while optionally a portion of the first casing string 315 is being rotated by the top drive or mud motor. At the same time, drilling fluid is introduced into the inner diameter of the second casing string 810. The drilling fluid forces the drillable portions within the inner diameter of the first casing string 310 upward toward the surface and forms a path through the first casing string 310 for the expandable cutting structure 805 to travel.
After the expandable cutting structure 805 has destroyed the cutting structure 315, the expandable cutting structure 805 is actuated so that the blades 806, 807 are in the extended position. The blades 806, 807 are extended when the nozzles 385 cause a hydraulic pressure differential within the second casing string 810, as described in the above-mentioned patent application which was incorporated by reference. In the extended position, the blades 806, 807 are capable of forming a portion of the wellbore 305 below the first casing string 310 with a larger inner diameter than the inner diameter of the first casing string 310 so that the second casing string 810 may be expanded to have the same inner diameter as the first casing string 310, thus forming a substantially monobore well.
The second casing string 810 is then lowered and optionally at least a portion of the second casing string 810 is rotated while circulating drilling fluid so that the second casing string 810 is drilled to a second depth within the formation 320. The inner diameter of the wellbore 305 below the first casing string 310 is larger than the inner diameter of the casing string 310.
Next, the expander tool 400 is lowered into the inner diameter of the first casing string 310 and the second casing string 810. Fluid is introduced through the working string 406 so that the pistons urge the rollers 416 against the inner diameter of the second casing string 810. The expander tool 400 rotates as the rollers are actuated and the expander tool 400 is urged upwards in the wellbore 305, so that the second casing string 810 is expanded along its length. A portion of the second casing string 810 is expanded into contact with the cut-away portion 325. As shown in
The expander tool 400 may be removed from the wellbore 305 after expansion of the second casing string 810 is completed.
After removal of the expander tool 400 from the wellbore 305, a cementing operation may optionally be conducted to cement the second casing string 810 within the formation 320. A physically alterable bonding material such as cement is introduced into the inner diameter of the first casing string 310, then flows through the inner diameter of the second casing string 810, through the nozzles 385, and up through the annular space 335. Additional casing strings with expandable cutting structures operatively attached thereto may be used to drill through the expandable cutting structure 805 and the additional expandable cutting structures.
In the operation of the second embodiment shown in
The first casing string 610 is drilled to the desired depth within the formation 620. To determine when the first casing string 610 has reached the desired depth within the formation 620, logging-while-drilling and/or measuring-while-drilling may be utilized, as is known by those skilled in the art. Specifically, one or more logging tools and/or measuring tools may be employed to determine by measuring one or more geophysical parameters in the formation 620 whether the first casing string 610 is proximate to the desired location. Exemplary geophysical parameters which may be sensed within the formation 620 include but are not limited to resistivity of the formation 620, pressure, and temperature.
After the first casing string 610 is drilled to the desired depth within the formation 620, the flow of drilling fluid is halted. A physically alterable bonding material, preferably a setting fluid such as cement, may then optionally be introduced into the first casing string 610 to fill at least a portion of the annular space 635 as described above in relation to the first casing string 310 of
Next, the second casing string 710 is lowered and optionally at least a portion of the second casing string 710 is rotated into the first casing string 610 as described in relation to casing strings 310 and 810 of
The expandable cutting structure 705 is then used to drill through the drillable material 612 of the cutting structure 615. The fluid circulating within the wellbore 605 carries the cutting members 613 through the annular space between the inner diameter of the first casing string 610 and the outer diameter of the second casing string 710 toward the surface. The expandable cutting structure 705 is then extended to the open position below the first casing string 605 as described above in relation to the expandable cutting structure 805 of
The second casing string 705 is drilled to a second desired depth within the formation 620. The expander tool 400 is then lowered into the wellbore 605 and is actuated to expand the second casing string 710 along its length as described above in relation to
At the end of the operation, the expander tool 400 may be removed from the wellbore 605. A physically alterable bonding material such as cement may optionally be introduced into the wellbore 605 and flowed through the casing strings 610, 710, through the nozzles 685, and up through the annular space 635 to cement the second casing string 710 within the wellbore.
In an additional aspect of the present invention, the second casing string 710 may also include an attenuator 505 at a lower portion around its outer diameter. Additional casing strings with expandable cutting structures attached thereto and attenuators around their outer diameters may then be used to drill through previous expandable cutting structures and experience expansion to compress the attenuators, as described above, to form a wellbore of a desired depth.
In a further additional, aspect of the present invention, a portion of the second casing string 710 is expanded into contact with the first casing string 610, and the portion of the second casing string 710 located above the attenuator 505 and extending into the inner diameter of the first casing string 610 is cut off of the second casing string 710.
In yet a further additional aspect of the present invention, the attenuator 505 or compressible member of
The cutting structures 315 and 615 and the expandable cutting structures 805 and 705 are described above as connected to the lower end of the casing strings 310, 810, 610, and 710. It is understood that the cutting structures 315, 615, 805, and 705 are operatively disposed at the lower end of the casing strings 310, 810, 610, and 710, so that the cutting structures may be disposed at any location on the casing strings where the cutting structures are capable of drilling through the formation. As such, it is understood that the cutting structure may be connected at, for example, a middle portion of the casing string, and the cutting structure may protrude below the casing string in a position to drill through the formation.
Providing a method and apparatus for drilling with casing to form a substantially monobore well by use of the embodiments of the present invention increases the possible inner diameter of a cased wellbore formed by drilling with casing. As a consequence, flexibility in the tools which are capable of being run into the cased wellbore is increased. Furthermore, forming a substantially monobore well using drilling with casing technology in embodiments of the present invention allows a wellbore of substantially the same inner diameter along its length to be formed in less time compared to conventional drilling methods.
Embodiments of the present invention also advantageously provide apparatus and methods for maintaining a fluid bypass around casing during a drilling with casing operation after hanging casing within an open hole or cased wellbore. Use of embodiments of the present invention allows for creation of a substantially monobore well by drilling with casing.
The earth removal member 950 is preferably a cutting structure, most preferably a drill bit, having one or more fluid passages 952 and/or 953 to allow for fluid flow therethrough. The earth removal member 950 may be an expandable cutting structure, the operation and structure of which is shown and described below in relation to the earth removal member 1550 of
The earth removal member 950 may be attached to any portion of the casing 910 which allows for drilling with the casing 910 into a formation 905. Preferably, the connection between the earth removal member 950 and the casing 910 is temporary to allow for retrieval of the earth removal member 950 during the drilling operation (described below).
The profiled casing 910 is shown in
One or more fluid bypass areas 940 are formed between the legs 935 to provide a fluid path around the outside of the casing 910. The casing 910 is preformed into an irregular, profiled shape to create the bypass areas 940. The fluid bypass areas 940, as well as the casing 910, may be of any shape which allows for sufficient circulation of fluid around the outside of the casing 910 after the casing has been hung within the wellbore 930 and also permits eventual expansion of the casing 910 circumferentially during the various stages of the drilling operation. Alternatively, the fluid bypass areas 940 may be formed downhole from casing which is substantially circumferential. A sealing member 960 may be disposed around the outer diameter of the casing 910 to seal between the casing 910 and the wellbore 930 upon expansion of the casing 910. The sealing member 960 is preferably an elastomeric ring.
Referring again to
An exploded view of the setting tool 1200 is shown in
An exploded view of the expander tool 1100 is shown in
The expander tool 1100 has a body 1102 which is hollow and generally tubular and may have connectors 1104 and 1106 for connection to other components (not shown) of the downhole assembly. The connectors 1104 and 1106 may be of a reduced diameter compared to the outside diameter of the longitudinally central body part of the expander tool 1100. The central body part has one or more recesses, shown here as three recesses 1114, to hold a respective expansion member, preferably a roller 1116. Each of the recesses 1114 has parallel sides and extends radially from a radially perforated tubular core (not shown) of the expander tool 1100. Each of the mutually identical rollers 1116 is generally cylindrical and barreled.
Each of the rollers 1116 is mounted by means of an axle 1118 at each end of the respective roller 1116 and the axles 1118 are mounted in slidable pistons 1120. The rollers 1116 are arranged for rotation about a respective rotational axis which is parallel to the longitudinal axis of the expander tool 1100 and, in the embodiment shown, radially offset therefrom at approximately 120-degree mutual circumferential separations around the central body 1102. The axles 1118 are formed as integral end members of the rollers 1116 and the pistons 1120 are radially slidable, one piston 1120 being slidably sealed within each radially extended recess 1114. The inner end of each piston 1120 is exposed to the pressure of fluid within the hollow core of the expander tool 1100 by way of the radial perforations in the tubular core. In this manner, pressurized fluid provided from the surface of the well, via the running string 1300, can actuate the pistons 1120 and cause them to extend outward and to contact the inner wall of the casing 910 to be expanded.
Additionally, at an upper and a lower end of the expansion tool 1100 are preferably a plurality of non-compliant rollers 1103 constructed and arranged to initially contact and expand the casing 910 prior to contact between the casing 910 and fluid actuated rollers 1116. Unlike the compliant, fluid actuated rollers 1116, the non-compliant rollers 1103 are supported only with bearings and do not change their radial position with respect to the body 1102 of the expander tool 1100.
As shown in
When using the expansion tool 1100, the casing being acted upon by the expansion tool 1100 is expanded past its point of elastic deformation. In this manner, the inner diameter and outer diameters of the expandable tubular are increased in the wellbore. By rotating the expansion tool 1100 in the wellbore and/or moving the expansion tool 1100 axially in the wellbore with the rollers 1116 actuated, the casing 910 can be expanded by plastic deformation into the wellbore 930 (or already existing casing of a cased wellbore).
In operation, the running string 1300 is initially made up to include the carrying dogs 931, expander tool 1100, and setting tool 1200 therein. The lower end of the running string 1300 is threadedly connected to the earth removal member 950 above its fluid passages 952 and 953. The running string 1300 components are configured so that the setting tool 1200 is located within the profiled portion of the casing 910 at the lower end of the casing 910. The carrying dogs 931 are extended into corresponding slots 932 in the casing 910. In this configuration, the casing 910 with the releasably connected running string 1300 is run into the formation 905. The earth removal member 950 may be rotated by a mud motor (not shown) while the casing 910 is being run into the formation 905. In the alternative, the entire casing string 910 including the earth removal member 950 may be rotated while running the casing 910 into the formation 905. It is also contemplated that, if the formation 905 is sufficiently soft, the casing 910 may be merely pushed into the formation 905 while circulating drilling fluid (“jetted”) into the formation 905 without rotating the earth removal member 950 or the casing 910. Any combination of rotating the earth removal member 950 only, rotating the casing 910, or jetting the casing 910 may also be utilized to drill the casing 910 into the formation 905 to form the wellbore 930.
While the casing string 910 is drilling into the formation 905, drilling fluid F is preferably introduced into the inner diameter of the running string 1300. The drilling fluid F then travels through the expander tool 1100 and setting tool 1200, through the passages 952 and 953 through the earth removal member 950 and out through the earth removal member 950, then up to the surface of the well through an annulus A between the outer diameter of the casing 910 and the inner diameter of the wellbore 930 which is being drilled. The casing string 910 is drilled to the desired depth within the formation 905, as shown in
Next, a ball 1291 is dropped into the bore 1180, as shown in
After the casing 910 has been expanded at the legs 935 into frictional contact with the wellbore 930, fluid pressure is increased within the bore 1280 to a fluid pressure above the rated limit of the ball seat 1290 to blow the ball 1291 out of the ball seat 1290. When the ball 1291 is blown out of the ball seat 1290, fluid flow through the bores 1180, 1280, and 980 within the running string 1300 is again unimpeded. At this point, the wellbore 930 may be conditioned and/or cemented by any conventional means. A cementing operation may be conducted by introducing cement or some other physically alterable bonding material into the running string 1300, as shown in
After sufficient cement has been introduced into the annulus A but before the cement has cured, the carrying dogs 931 are retracted from the slots 932 and the temporary connection 951 connecting the earth removal member 950 to the casing 910 is released. The temporary connection 951 is preferably released by shearing the earth removal member 950 from the casing 910 by downward pushing or upward pulling of the running string 1300. Drilling fluid F is then introduced into the running string 1300 and the mud motor rotates the earth removal member 950 to drill the running string 1300 to a further depth within the formation 905. Other methods of drilling mentioned above, including rotating the entire running string 1300 or jetting the running string 1300 into the formation 905 may also be utilized, alone or in combination with one another. The running string 1300 is drilled to a further depth within the formation 905 to allow location of the expander tool 1100 adjacent the profiled lower end of the casing 910 within the casing 910.
Next, the drilling of the running string 1300, is halted, and fluid flow through the running string 1300 may be stopped. The running string 1300 is preferably drilled to the depth where the expander tool 1100 is located at the lowermost end of the casing 910. In this embodiment, the expansion of the casing 910 is from the bottom up. In the alternative, the expander tool 1100 may be located adjacent to the upper end of the profiled portion of the casing 910, if the expander tool 1100 is moved downward for the expansion of the profiled portion of the casing 910.
As shown in
Gravity and the weight of the components can move the expander tool 1100 downward in the casing 910 even as the rollers 1116 of the expander tool 1100 are actuated. Alternatively, the expansion can take place in a “bottom up” fashion by providing an upward force on the running string 1300. A tractor (not shown) may be used in a lateral wellbore or in some other circumstance when gravity and the weight of the components are not adequate to cause the actuated expander tool 1100 to move downward along the wellbore 930. Additionally, the tractor may be necessary if the expander tool 1100 is to be used to expand the casing 910 wherein the tractor provides upward movement of the expander tool 1100 in the wellbore 930. Preferably, the non-compliant rollers 1103 at the lower end of the expander tool 1100 contact the inner diameter of the casing 910 as the expansion tool 1100 is raised. This serves to smooth out the legs 935 and reform the casing 910 into a circular shape prior to fully expanding the casing 910 into the wellbore 930. The casing 910 is then expanded into circumferential contact with the wellbore 930.
The expander tool 1100 is preferably then utilized to expand the remainder of the casing 910 above the profiled portion to a desired extent, preferably leaving at least some cement outside the casing 910 to securely set the casing 910 within the wellbore 930. The remaining portion of the casing 910 may be expanded from the bottom up or from the top down. Expanding this remaining portion increases the inner diameter of the casing 910 along its length, thus expanding the available diameter within the wellbore 930. After the expansion is complete, the cement may be allowed to cure to set the casing 910 within the wellbore 930.
Fluid pressure is then increased to a pressure above the operating pressure of the expander tool 1100 to blow the ball 1191 through the frangible ball seat 1190. The ball 1191 then flows through the running string 1300 and to the surface with the fluid up through the annulus between the inner diameter of the casing 910 and the outer diameter of the running tool 1300. Consequently, a fluid path through the bores 980, 1180, and 1280 is again unobstructed and the rollers 1116 of the expander tool 1100 are retracted. The retractable earth removal member 950 is retracted, and the running string 1300 is removed from the wellbore 930.
In an alternate embodiment, the earth removal member 950 may be drillable rather than retractable. While a ball and ball seat arrangement is described, it should be understood that any appropriate valve arrangement may be used, such as a dart or a sleeve for isolating fluid flow from the running string 1300 to the setting tool 1200 and/or expander tool 1100.
An earth removal member 1550 is operatively connected to a lower end of the casing 1500. As shown in
The expandable earth removal member 1550 may be retrievable after expansion in its retracted state. In the alternative, the expandable cutting structure 1550 may be an expandable drill bit constructed of drillable material such as aluminum, as described in the above incorporated by reference application. The expandable drill bit of the application incorporated above has a plurality of cutting members disposed on an outer portion of the blades. The cutting members are typically small and substantially spherical, and may be made of tungsten carbide or polycrystalline diamond surfaces. The blades are constructed and arranged to permit the cutting members to contact and drill the earth when the blades are expanded outward and not ream the wellbore or surrounding casing when the blades are collapsed inward.
Fluid passages 1552 and 1553 extend through the earth removal member 1550 to provide a fluid path through the earth removal member 1550. Fluid passages 1552 and 1553 are in fluid communication with a longitudinal bore through the casing and allow jetting of the drilling fluid during the drilling operation through the casing to remove any cuttings build up which may gather in front of the blades and to form a path for the casing through the formation. Furthermore, the fluid passages 1552 and 1553 (also termed nozzles) are used to create a hydraulic pressure differential within the bore through the casing to cause the blades of the expandable cutting structure to expand outward, as described in U.S. application Ser. No. 10/335,957, incorporated by reference above.
The casing 1500 may optionally include one or more sealing members 1560 on its outer diameter for sealing an annular area A between the casing 1500 and the wellbore 1510. Additionally, the casing 1500 may optionally include one or more gripping members 1520 on a portion of its outer diameter to allow the casing 1500 to be initially hung within the wellbore 1510 due to frictional engagement of the gripping members 1520 with the wellbore 1510. The sealing members 1560 are preferably constructed of an elastomeric material, and the gripping members 1520 are preferably slips. Preferably, the sealing members 1560 and gripping members 1520 are located below the openings 1525, and the sealing members 1560 are located above the gripping members 1520 on the casing 1500.
A running string 1570 is releasably connected to the casing 1500, preferably by retractable carrying dogs 1531 disposed in slots 1532 in the inner diameter of the casing 1500. The expander tool 1100 shown and described in relation to
In operation, as shown in
Next, as illustrated in
The carrying dogs 1531 are next retracted from the slots 1532 in the casing 1500, and the earth removal member 1550 is removed from its releasable engagement with the casing 1500. The expander tool 1100 may now be rotated relative to the casing 1500 to expand the casing 1500 along its circumference into the wellbore 1510, as described above in relation to
The expander tool 1100 exerts force against the wall of the casing 1500 while rotating and moving axially within the casing 1500. The rollers 1116 thereby expand the casing 1500 wall past its elastic limit around the circumference of the casing 1500 at the lower end. Alternatively, the expansion can take place in a “bottom up” fashion by providing an upward force on the running string 1570, as described above in relation to
Fluid pressure in the running string 1570 is then increased to a pressure above the operating pressure of the expander tool 1100. The ball 1591 is blown through the frangible ball seat 1590, then flows up to the surface with the fluid up through the annulus A. The rollers 1116 of the expander tool 1100 are thus retracted due to lack of fluid pressure within the expander tool 1100, and the bore 1580 is again unobstructed to allow fluid flow therethrough.
As shown in
When sufficient setting fluid 1555 exists in the annulus A, setting fluid 1555 is no longer introduced into the running string 1570. After halting the setting fluid 1555 flow, the running string 1570 is moved axially upward within the wellbore 1510 so that the rollers 1116 of the expander tool 1100, upon radial extension, contact the unexpanded portion of the casing 1500 which is above the portion of the casing 1500 already expanded into the wellbore 1510. A second ball (not shown), which is larger than the ball 1591, may be introduced into the running string 1570. The second ball stops in a second ball seat (not shown), which is larger than the ball seat 1590. Again, pressurized fluid is flowed into the bore 1580 of the running string 1570 to force the rollers 1116 radially outward, and the expander tool 1100 is rotated and moved upward axially to expand the portion of the casing 1500 having the openings 1525 therein into contact with the wellbore 1510. Expanding the openings 1525 into the wellbore 1510 prevents the openings 1525 from becoming a weak spot in the casing 1500 of the cased wellbore, and closes off the ports into the annulus A.
To move the expander tool 1100 upward axially, the earth removal member 1550 may be retracted to allow it to fit within the inner diameter of the casing 1500 by methods such as those disclosed in U.S. patent application Ser. No. 10/335,957, which was above incorporated by reference.
Before the setting fluid 1555 cures, the upper portion of the casing 1500 above the openings 1525 is preferably expanded by the expander tool 1100 to some extent to increase the available space within the inner diameter of the casing 1500. This upper portion may be expanded from the bottom up, or from the top down. Preferably, the upper portion is not expanded into frictional contact with the wellbore so that at least some setting fluid 1555 remains within the annulus A to set the casing 1500 within the wellbore 1510.
The running string 1570 is then removed from the wellbore 1510. The setting fluid 1555 may be allowed to cure to set the casing 1500 within the wellbore 1510.
An additional casing (not shown) may then be drilled into the wellbore 1510 in the same manner as described in relation to casing 1500, and then the upper portion of the additional casing expanded into the lower portion of the casing 1500, according to the method described in
In another embodiment, the earth removal member 1550 of the embodiment shown in
The expander tool 1100 described above in relation to the operations shown in
In another aspect, the present invention provides a method of drilling a lateral wellbore comprising forming the lateral wellbore from a parent wellbore in a manner whereby an inner diameter of the lateral wellbore is at least as large as an inner diameter of the parent wellbore. In one embodiment, the lateral wellbore is formed in a single trip into the well. In another embodiment, the lateral is formed with an expandable bit. In another embodiment still, the lateral wellbore is formed with a bit located at the end of a string of liner. In another embodiment still, the parent wellbore is lined with casing. In another embodiment still, the method includes placing a liner in the lateral wellbore. In another embodiment still, the liner is expanded into contact with the lateral wellbore. In another embodiment still, an inner diameter of the liner is at least as large as the inner diameter of the parent wellbore.
In another aspect, the present invention provides a wellbore junction between a patent wellbore and a lateral wellbore comprising a window leading from the parent wellbore to the lateral wellbore, the window having at least one dimension thereacross greater than any corresponding dimension of the parent wellbore.
In another aspect, the present invention provides a method of forming a lined lateral wellbore comprising forming a lateral wellbore extending from a main wellbore, wherein a diameter of the lateral wellbore is larger than an inner diameter of casing lining the main wellbore, running an expandable tubular element, through the casing lining the main wellbore, into the lateral wellbore, and expanding the tubular element within the lateral wellbore, such that the expanded-tubular element has an outer diameter larger than the drift diameter of the casing lining the main wellbore. In one embodiment, an inner diameter of the expanded tubular element is greater than an inner diameter of the casing lining the main wellbore. In another embodiment, the method includes cementing the tubular element into the lateral wellbore. In another embodiment still, the cementing is done after the expanding. In another embodiment still, the expandable tubular element is run into the lateral wellbore as the lateral wellbore is formed. In another embodiment still, the lateral wellbore is formed by drilling with a drilling member disposed on a bottom portion of the expandable tubular element. In another embodiment still, the drilling member is an expandable bit adapted to be drilled through by a subsequent bit without substantially damaging the subsequent bit. In another embodiment still, the drilling member a drill bit that is part of a bottom hole assembly comprising one or more tools in addition to the drill bit. In another embodiment still, at least one of the tools is a tool adapted to measure one or more downhole parameters and the method further comprises measuring one or more downhole parameters while forming the lateral wellbore. In another embodiment still, at least one of the tools is an expandable stabilizer. In another embodiment still, the method includes retrieving at least one of the tools after forming the lateral wellbore. In another embodiment still, forming the lateral wellbore comprises removing a section of the casing lining the main wellbore to form an uncased cavity; inserting a physically alterable bonding material into the cavity; and drilling the lateral wellbore through the physically alterable bonding material. In another embodiment still, the method includes expanding the diameter of the lateral wellbore to receive the expandable tubular element. In another embodiment still, the method includes drilling through the physically alterable bonding material to provide fluid communication between the lateral wellbore and a portion of the main wellbore below a junction between the lateral wellbore and the main wellbore. In another embodiment still, forming the lateral wellbore comprises expanding at least a portion of the lateral wellbore by drilling with an expandable drill bit. In another embodiment still, the method includes forming the main wellbore and lining the main wellbore with expandable tubular elements.
In another aspect, the present invention provides a method of forming a lined lateral wellbore comprising securing a diverter within a main wellbore lined with casing; forming a lateral wellbore with an earth removal member guided by the diverter; expanding a diameter of at least a portion of the lateral wellbore; running an expandable tubular element through the casing lining the main wellbore into the lateral wellbore; and expanding the tubular element within the lateral wellbore, such that the expanded tubular element has an inner diameter equal to or larger than the inner diameter of the casing lining the main wellbore. In one embodiment, the method includes removing the diverter prior to expanding the diameter of at least a portion of the lateral wellbore. In another embodiment, expanding the diameter of at least a portion of the lateral wellbore comprises expanding a portion of the lateral wellbore extending to the main wellbore. In another embodiment still, expanding the diameter of at least a portion of the lateral wellbore comprises operating an expandable back reamer. In another embodiment still, after expanding the tubular element within the lateral element, the expanded portion of the lateral wellbore extending to the main wellbore is fully lined with the expanded tubular element. In another embodiment still, after running the tubular element into the lateral wellbore, a portion of the tubular element extends into the main wellbore and the method further comprises, after expanding the tubular element, removing the portion of the tubular element extending into the main wellbore.
In another aspect, the present invention provides a lateral wellbore extending from a main wellbore lined with casing, wherein at least a portion of the lateral wellbore is lined with casing, the lined portion of the lateral wellbore having an outer diameter larger than a drift diameter of the main wellbore casing. In one embodiment, the inner diameter of the lateral wellbore is equal to or greater than an inner diameter of the main wellbore casing. In another embodiment, the lined portion of the lateral wellbore extends to the main wellbore. In another embodiment still, the lined portion of the lateral wellbore is lined with an expanded screen material. In another embodiment still, the lined portion of the lateral wellbore is lined with a solid expanded tubular element. In another embodiment still, the main wellbore is lined with an expanded tubular element. In another embodiment still, at least a portion of the lateral wellbore casing is cemented into the lateral wellbore.
In another aspect, the present invention provides a method of forming a cased wellbore comprising drilling a wellbore using a first casing string having an earth removal member operatively disposed at its lower end; locating the first casing string within the wellbore; locating a portion of a second casing string adjacent to a portion of the first casing string having an enlarged inner diameter; and expanding the portion of the second casing string so that the portion of the second casing string has an inner diameter at least as large as a smallest inner diameter portion of the first casing string. In one embodiment, at least one compressible member is disposed within the portion of the first casing string having the enlarged inner diameter. In another embodiment, expanding the portion of the second casing string comprises compressing at least a portion of the at least one compressible member. In another embodiment still, at least one compressible member comprises a plurality of webs moveable through at least one void area upon compression. In another embodiment still, at least one compressible member comprises a porous material. In another embodiment still, the inner diameter of the expanded portion of the second casing string is substantially equal to the smallest inner diameter portion of the first casing string. In another embodiment still, the second casing string has an earth removal member operatively attached to its lower end. In another embodiment still, the earth removal member of the second casing string comprises an expandable cutting structure. In another embodiment still, locating a portion of the second casing string adjacent to a portion of the first casing string comprises drilling through the first casing string with the second casing string. In another embodiment still, the earth removal member comprises a drillable material. In another embodiment still, the method includes setting the second casing string within the wellbore using a physically alterable bonding material. In another embodiment still, the portion of the first casing string with the enlarged inner diameter is an undercut cementing shoe. In another embodiment still, the method includes locating a portion of a third casing string adjacent to a portion of the second casing string having an enlarged inner diameter and expanding the portion of the third casing string so that the portion of the third casing string has an inner diameter at least as large as the smallest inner diameter portion of the first casing string.
In another aspect, the present invention provides a method of forming a cased wellbore comprising drilling a wellbore using a first casing string having an earth removal member operatively connected to its lower end and at least one compressible member disposed around at least a portion of the first casing string; locating the first casing string within the wellbore; locating a portion of a second casing string adjacent to the at least one compressible member; and expanding the portion of the second casing string so that the portion of the second casing string has an inner diameter at least as large as a smallest inner diameter portion of the first casing string. In one embodiment, at least one compressible member is disposed at a lower end of the first casing string. In another embodiment, locating the portion of the second casing string adjacent to the at least one compressible member comprises drilling through the earth removal member. In another embodiment still, the second casing string comprises an earth removal member operatively connected to its lower end. In another embodiment still, the earth removal member of the second casing string is extendable to form an enlarged wellbore below the first casing string. In another embodiment still, the inner diameter of the expanded portion of the second casing string is substantially equal to the smallest inner diameter portion of the first casing string. In another embodiment still, the at least one compressible member comprises a plurality of webs moveable through at least one void area upon compression. In another embodiment still, the at least one compressible member comprises a porous material. In another embodiment still, the method includes setting the second casing string within the wellbore using a physically alterable bonding material. In another embodiment still, the second casing string has a at least one compressible member disposed on its lower end. In another embodiment still, the method includes locating a portion of a third casing string adjacent to the compressible member of the second casing string and expanding the portion of the third casing string so that the portion of the third casing string has an inner diameter at least as large as the smallest inner diameter portion of the first casing string.
In another aspect, the present invention provides an apparatus for use in forming a cased wellbore comprising a casing string, an earth removal member operatively attached to a lower end of the casing string, and at least one compressible member disposed at a lower end of the casing string. In one embodiment, the earth removal member comprises a drillable material. In another embodiment, at least one compressible member includes a compressible material having at least one void formed therein. In another embodiment still, at least one compressible member is disposed around an outer surface of the casing string. In another embodiment still, at least one compressible member is disposed within a portion of the casing string having an enlarged inner diameter. In another embodiment still, at least one compressible member comprises a porous material.
In another embodiment still, at least one compressible member comprises a wall adjacent to the casing string and a plurality of compressible webs connecting the wall to the casing string. In another embodiment still, the plurality of compressible webs is moveable through a plurality of void areas between the plurality of webs.
In another embodiment, the present invention provides an apparatus for use in forming a cased wellbore comprising a casing string having an enlarged inner diameter portion; an earth removal member operatively connected to a lower end of the casing string; and a drillable portion disposed in the enlarged inner diameter portion. In one embodiment, the earth removal member comprises a drillable material. In another embodiment, the enlarged inner diameter portion is located at a lower end of the casing string. In another embodiment still, the drillable portion is constructed and arranged to become dislodged from the casing string when drilled with a second casing string having an outer diameter smaller than the enlarged inner diameter portion. In another embodiment still, the drillable portion is weakened by a plurality of voids formed therein. In another embodiment still, the plurality of voids formed in the drillable portion terminate at an inner surface of the enlarged inner diameter portion. In another embodiment still, at least a portion of the drillable portion includes a composite material.
In another embodiment, the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path. In one aspect, the method further comprises accomplishing the lowering, expanding, leaving, flowing, and closing in a single trip into the wellbore.
Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path, wherein closing the fluid path provides a seal between the first casing and the wellbore. Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path, wherein the fluid is setting fluid. In one embodiment, the setting fluid is cement.
Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path, wherein the at least a portion of the first casing is profiled and the fluid path comprises one or more fluid bypass areas formed in the profiled portion of the first casing. Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path, wherein the fluid path comprises one or more openings in the first casing to allow the setting fluid to flow into an annulus between the first casing and the wellbore. Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; closing the fluid path; and expanding at least a portion of an unexpanded portion of the first casing.
Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path, wherein a lower end of the first casing is expanded further radially than a remaining portion of the first casing. In one aspect, the first casing is bell-shaped. Another embodiment of the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; closing the fluid path; and lowering a second casing having an earth removal member operatively attached to its lower end into the formation to form a wellbore of a second depth. In one embodiment, the method further comprises expanding at least a portion of the second casing into gripping engagement with the wellbore to hang the second casing within the wellbore. In another embodiment, the method further comprises leaving a second fluid path between the second casing and the wellbore after expanding at least the portion of the second casing; flowing a setting fluid through the second fluid path; and closing the second fluid path.
In another embodiment, the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; and closing the fluid path, wherein closing the fluid path comprises expanding the fluid path into the wellbore. In another embodiment, the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; closing the fluid path, wherein a lower end of the first casing is expanded further radially than a remaining portion of the first casing; and lowering a second casing into the wellbore to a second depth and expanding the second casing into the first casing to form a substantially monobore well. In another embodiment, the present invention includes a method of forming a cased well, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore of a first depth; expanding at least a portion of the first casing into gripping engagement with the wellbore to hang the first casing within the wellbore; leaving a fluid path between the first casing and the wellbore after expanding at least the portion of the first casing; flowing a fluid through the fluid path; closing the fluid path; and rotating the first casing while lowering the first casing into the formation.
Another embodiment of the present invention includes a method of casing a wellbore, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore, the first casing having at least one bypass for circulating a fluid formed therein; expanding at least a portion of the first casing into frictional engagement with the wellbore to hang the first casing within the wellbore; circulating the fluid through the at least one bypass; and expanding the first casing to close the bypass. In one embodiment, a running string comprising a setting tool therein is disposed within the first casing to hang the first casing within the wellbore. In another embodiment, the running string further comprises an expander tool to close the bypass.
Another embodiment of the present invention includes a method of casing a wellbore, comprising lowering a first casing having an earth removal member operatively attached to its lower end into a formation to form a wellbore, the first casing having at least one bypass for circulating a fluid formed therein; expanding at least a portion of the first casing into frictional engagement with the wellbore to hang the first casing within the wellbore; circulating the fluid through the at least one bypass; and expanding the first casing to close the bypass, wherein a lower end of the first casing is expanded to a larger inner diameter than a remaining portion of the first casing. In one embodiment, the method further comprises lowering a second casing having an earth removal member operatively attached to its lower end into the formation to form the wellbore. In another embodiment, the method further comprises expanding the second casing into the first casing to form a substantially monobore well.
Another embodiment of the present invention includes an apparatus for use in drilling with casing, comprising a tubular string having a casing portion, an earth removal member operatively attached to its lower end, and at least one fluid bypass area located thereon; and an expansion tool disposed within the tubular string, the expansion tool capable of expanding a portion of the tubular string into a surrounding wellbore while leaving a flow path around an outer diameter of the tubular string to a surface of the wellbore. In one aspect, the at least one fluid bypass area comprises at least one longitudinal profile in the tubular string. In another aspect, the at least one fluid bypass area comprises at least one opening in the tubular string.
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 claims benefit of U.S. Provisional Patent Application Ser. No. 60/451,994 filed on Mar. 5, 2003, which application is herein incorporated by reference in its entirety. This application further claims benefit of U.S. Provisional Patent Application Ser. No. 60/452,269 filed on Mar. 5, 2003, which application is herein incorporated by reference in its entirety.
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| WO 9006418 | Jun 1990 | WO |
| WO 9116520 | Oct 1991 | WO |
| WO 9201139 | Jan 1992 | WO |
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| WO 9307358 | Apr 1993 | WO |
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| WO 0011309 | Mar 2000 | WO |
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| WO 0011311 | Mar 2000 | WO |
| WO 0028188 | May 2000 | WO |
| WO 0037766 | Jun 2000 | WO |
| WO 0037771 | Jun 2000 | WO |
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| WO 0077431 | Dec 2000 | WO |
| WO 0112946 | Feb 2001 | WO |
| WO 0146550 | Jun 2001 | WO |
| WO 0160545 | Aug 2001 | WO |
| WO 0166901 | Sep 2001 | WO |
| WO 0179650 | Oct 2001 | WO |
| WO 0181708 | Nov 2001 | WO |
| WO 0183932 | Nov 2001 | WO |
| WO 0194738 | Dec 2001 | WO |
| WO 0194739 | Dec 2001 | WO |
| WO 0214649 | Feb 2002 | WO |
| WO 0229199 | Apr 2002 | WO |
| WO 0233212 | Apr 2002 | WO |
| WO 0244601 | Jun 2002 | WO |
| WO 02081863 | Oct 2002 | WO |
| WO 02086287 | Oct 2002 | WO |
| WO 02092956 | Nov 2002 | WO |
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| Number | Date | Country | |
|---|---|---|---|
| 20040244992 A1 | Dec 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60451994 | Mar 2003 | US | |
| 60452269 | Mar 2003 | US |
