Patent Application
20060124357
1. Field of the Invention
Embodiments of the present invention generally relate to an apparatus and method for handling tubulars and drilling with tubulars to form a wellbore. More particularly, embodiments of the present invention relate to drilling with casing. Even more particularly, embodiments of the present invention relate to a gripping apparatus for supporting casing for use in a drilling with casing operation.
2. Description of the Related Art
In conventional well completion operations, a wellbore is formed to access hydrocarbon-bearing formations by the use of drilling. In drilling operations, a drilling rig is disposed above the subterranean formation where the access will be formed. A rig floor of the drilling rig is the surface from which casing strings, cutting structures, and other supplies are lowered to form a subterranean wellbore lined with casing. A hole is formed in a portion of the rig floor above the desired location of the wellbore. The axis that runs through the center of the hole formed in the rig floor is well center.
Drilling is accomplished by utilizing a drill bit that is mounted on the end of a drill support member, commonly known as a drill string. To drill within the wellbore to a predetermined depth, the drill string is often rotated by a top drive or rotary table on the drilling rig. After drilling to a predetermined depth, the drill string and drill bit are removed and a section of casing is lowered into the wellbore.
Often, it is necessary to conduct a pipe handling operation to connect sections of casing to form a casing string or to connect sections of tubular to form a tubular string. The pipe handling operation to connect sections of casing may be used to produce a casing string which extends to the drilled depth. Pipe handling operations require the connection of casing sections to one another to line the wellbore with casing. To threadedly connect the casing strings, each casing section may be retrieved from its original location (e.g., a rack beside the drilling platform) and suspended above well center so that each casing section is in line with the casing section previously disposed within the wellbore. The threaded connection is made up by a device which imparts torque to one casing section relative to the other, such as a power tong or a top drive. The casing string formed of the two casing sections is then lowered into the previously drilled wellbore.
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. Sections of casing are connected to one another and lowered into the wellbore using the pipe handling operation described above to form a first string of casing longitudinally fixed in the drilled out portion of the wellbore. Next, the well is drilled to a second designated depth through the first casing string, and a second, smaller diameter string of casing comprising casing sections is hung off of the first string of casing. This process is typically repeated with additional casing strings until the well has been drilled to total depth. In this manner, wellbores are typically formed with two or more strings of casing.
The handling of casing strings has traditionally been performed with the aid of a spider along with an elevator. Spiders and elevators are used to grip the casing strings at various stages of a pipe handling operation. Typically, spiders include a plurality of slips circumferentially surrounding the exterior of the casing string. The slips are housed in what is commonly referred to as a “bowl”. The bowl is regarded to be the surfaces on the inner bore of the spider. The inner sides of the slips usually carry teeth formed on hard metal dies for engaging the pipe string. The exterior surface of the slips and the interior surface of the bowl have opposing engaging surfaces which are inclined and downwardly converging. The inclined surfaces allow the slip to move vertically and radially relative to the bowl. In effect, the inclined surfaces serve as a camming surface for engaging the slip with the casing string. Thus, when the weight of the casing string is transferred to the slips, the slips will move downwardly with respect to the bowl. As the slips move downward along the inclined surfaces, the inclined surfaces urge the slips to move radially inward to engage the casing string. In this respect, this feature of the spider is referred to as “self tightening.” Further, the slips are designed to prohibit release of the casing string until the casing string load is supported by another means such as the elevator.
In the making up or breaking out of casing string and/or tubular string connections, the spider is typically used for securing the casing string or tubular string in the wellbore. Additionally, an elevator suspended from a rig hook is used in tandem with the spider. The elevator may include a self-tightening feature similar to the one in the spider. In operation, the spider remains stationary while securing the casing string in the wellbore. The elevator positions a casing string section above the casing string for connection. After completing the connection, the elevator pulls up on the casing string to release the casing string from the slips of the spider. Freed from the spider, the elevator may now lower the casing string into the wellbore. Before the casing string is released from the elevator, the spider is allowed to engage the pipe string again to support the casing string. After the load of the casing string is switched back to the spider, the elevator may release the casing string and continue the makeup process.
As an alternative to the conventional method, drilling with casing is a method often used to place casing strings within the wellbore. This method involves attaching a cutting structure in the form of a drill bit to the lower end of the same string of casing which will line the wellbore. Drilling with casing is often the preferred method of well completion because only one run-in of the working string into the wellbore is necessary to form and line the wellbore for each casing string.
Drilling with casing is typically accomplished using a top drive powered by a motor because the top drive is capable of performing both functions of imparting torque to the casing string to make up the connection between casing strings during pipe handling operations and drilling the casing string into the formation.
Current spiders and elevators useable in drilling with casing operations are capable of either being actuated to grippingly engage the casing string to prevent rotational or axial movement of the casing string or, in the alternative, of being unactuated to release the casing string completely to allow axial and rotational movement of the casing string while the casing string is drilled into the formation. Because only these two positions are possible with current gripping apparatuses, problems occur when using the gripping apparatuses while drilling with casing. When performing a drilling with casing operation with the current spiders or elevators in the unactuated position, the casing string is not centered within the wellbore while drilling because the casing string is not supported along its diameter and thus is free to move within the wellbore while drilling. Furthermore, because the casing string is loose inside the gripping apparatus, the slips of the gripping apparatus often contact the outer diameter of the casing string being rotated while drilling and can cause damage to the casing string. When the slips contact the outer diameter of the casing string, damage may also result to the slips. Additionally, the rotational movement is hindered in the current gripping apparatus by any contact of the casing string with parts of the gripping apparatus.
There is therefore a need for a gripping apparatus useful during a drilling with casing operation. There is a further need for a gripping apparatus which is capable of accommodating more than one pipe size so that the casing is centered on the well center while drilling with casing. There is an even further need for a gripping apparatus which allows the casing string to freely rotate while preventing damage to the casing and positioning the casing over the well center during a drilling with casing operation.
Embodiments of the present invention generally provide a gripping apparatus for supporting a casing. In one aspect, the apparatus includes a housing having a longitudinal opening extending therethrough and one or more gripping members which, when the gripping apparatus is actuated, move radially toward the casing to contact the casing. In another aspect, the apparatus may include one or more guides to facilitate movement of the casing within the housing of the gripping apparatus. The one or more guides may be positioned around the opening in a manner capable of centering the pipe. The one or more guides may be adjustable radially within the opening to accommodate different sizes of casing.
In another embodiment, the one or more guides may comprise one or more rolling members in the vertical position, wherein the one or more rolling members are positioned so that an axis of the rolling members is parallel to an axis of the longitudinal opening so that the rolling members are capable of imparting a rolling motion along the inner diameter of the casing while the casing is rotated. The rolling members may be adjustable between the parallel position and a position wherein the axis of the rolling members is perpendicular to the axis of the casing. In another aspect, the rolling members may be adjustable to a position between the parallel position and the perpendicular position.
Providing guides with rolling members in the vertical position allows the casing to be rotated to drill with the casing without contacting the one or more gripping members with the casing. Furthermore, the guides of the present invention allow the casing to be centered within the gripping apparatus and the wellbore for the drilling with casing operation or the casing lowering operation.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
The body 10 of the gripping apparatus 100 may be formed by pivotally coupling two body sections 11, 12 with one or more connectors 35. Connectors 35 may be used to couple the two body sections 11, 12 together upon placement in the rotary table 145. The connectors 35 may be hinges disposed on both sides of each body section 11, 12. Alternatively, the body sections 11, 12 may be hinged on one side and selectively locked together on the other side. A gap 37 exists between each connector 35 on body section 11 for mating with its respective connector 35 formed on body section 12. Likewise, a gap 37 exists between each connector 35 on body section 12 for mating with its respective connector 35 formed on body section 11. A hole 38 is formed through each connector 35 to accommodate at least one connecting member such as a pin 40. The holes 38 in the connectors 35 are substantially aligned so that the pin 40 may be disposed through the holes 38 to secure the two body sections 11, 12 together to form the body 10.
A bowl 25 extends vertically through a lower portion of the body 10 to house the gripping members 20. The bowl 25 is a progressive recess along an inner wall of the body sections 11, 12. The progressive recess of the bowl 25 creates an inclined portion of the inner wall, which mates with the back of the gripping members 20. The gripping members 20 preferably comprise a slip assembly comprised of slips for engaging the casing string 210 and/or 130 upon activation.
The body 10 of the gripping apparatus 100 is covered by the cover assembly 15, which may also have two or more separate sections placed above the respective body sections 11, 12. If the cover assembly 15 is sectioned in this way, the cover assembly 15 may open and close along with the body 10 of the gripping apparatus 100. The sections of the cover assembly 15 form a hole whose center generally coincides with the center of the body 10. The cover assembly 15 has holes 5 which extend therethrough to mate with holes 7 through the body 10. One or more connecting members such as pins 6 are placed through the holes 5 and the holes 7 to rotationally and axially fix the cover assembly 15 relative to the body 10.
Preferably, the guides 80 are adjustable radially inward and outward from the cover assembly 15 to accommodate various casing string 210, 130 sizes. To this end, the clevis 82 may include a shaft 88 insertable into a mounting device 90 for attachment to the cover assembly 15. The shaft 88 may be adjustable within the mounting device 90 to radially extend or contract the rollers 80 with respect to the mounting device 90 so that the gripping apparatus 100 is useable with various casing string sizes (diameters). The shaft 88 may be adjusted to extend or retract the rollers 84 manually, hydraulically, by a fluid-operated piston/cylinder assembly, by means of a solenoid arrangement, or any other suitable mechanism. Further, such adjustment mechanism may be integrated with a fluidic or electric control system to facilitate remote control and position monitoring. The guides 80 may be adjusted radially inward or outward so that each guide is the same distance from the cover assembly 15. In the alternative, if the three guides 80 are used (or at least multiple guides 80), the guides 80 may be adjusted radially inward or outward so that one of the guides 80 is at a distance from the cover assembly 15 greater than the distance between the two remaining guides 80 and the cover assembly 15. The guides 80 may be adjusted to exist at different distances from the cover assembly 15, for example, to accommodate a casing string which is to be inserted into the gripping apparatus 100 which is not in line with the central axis of the gripping apparatus 100.
In another aspect of the present invention, the guides 80 may be adjustable between the vertical position with respect to the cover assembly 15, as shown in
In operation, the spider 100 is flush mounted in the rotary table 145, as shown in
The rollers 84 may also be adjusted radially outward or inward from the gripping apparatus 100 to accommodate the diameter of the first casing string 210. The shaft 88 of the clevis 82 moves through the mounting device 90 to adjust the rollers 84 radially. The shaft 88 may be moved through the mounting device 90 manually or by fluid pressure contacting an end of the shaft 88 opposite the clevis 82.
After any adjustments to the gripping apparatus 100 are accomplished, the first casing string 210 may be retrieved from its original location, such as a rack (not shown), and if necessary through a v-door (not shown) of the drilling rig 105 by the elevator 200. The elevator 200 comprises a clamp (not shown) with one or more gripping members such as slips (not shown) which grippingly engage the first casing string 210, preferably below a coupling (not shown) threaded onto the upper portion of the first casing string 210. It is contemplated that the first casing string 210 may alternatively be grippingly engaged at any other location on the first casing string 210 than the coupling. The first casing string 210 may comprise one section of casing or may comprise any number of casing sections connected, preferably threaded together.
After the first casing string 210 is connected to a lower end of the top drive 110, the first casing string 210 is lowered into the wellbore 180 while simultaneously rotating. The first casing string 210, which preferably has an earth removal member such as a cutting structure (not shown) (preferably a drill bit) disposed at its lower end to drill the wellbore 180, is lowered into the wellbore 180 by cables 150 traveling through the draw works 120. Because the gripping members 20 are initially unactuated and in a retracted position within the bowl 25, the first casing string 210 is allowed to move downward through the spider 100. At the same time that the first casing string 210 is moving downward, the first casing string 210 may be rotated by the motor 140 of the top drive 110 so that the cutting structure located at the lower end of the first casing string 210 drills into a formation 215 below the drilling rig 105 to form the wellbore 180. While the first casing string 210 is rotating, the draw works 120, cables 150, traveling block 115, top drive 110, and elevator 200 resist the torque imparted by the top drive 110, and therefore are rotationally fixed. As the first casing string 210 is drilled into the formation 215 by the top drive 110, the gripping members 20 of the spider 100 remain unactuated so that they do not engage the outer diameter of the first casing string 210. As such, the first casing string 210 is allowed to move downward to form the wellbore 180. Furthermore, because the rollers 84 are previously oriented vertically, the first casing string 210 is allowed to rotate with respect to the wellbore 180 as well as with respect to the body 10 of the spider 100, so that a drilling with casing operation may be performed through the spider 100.
After the first casing string 210 is drilled into the formation 215 to the desired depth so that an upper portion of the first casing string 210 still exists above the rig floor 135, the spider 100 is activated so that the gripping members 20 engage the upper portion of the first casing string 210 and prevent the first casing string 210 from further downward movement into the wellbore 180. The gripping members 20 are activated to move along the incline of the bowl 25 to grip the first casing string 210. The gripping members 20 may be urged along the incline of the bowl 25 by a piston and cylinder assembly, as shown in co-pending U.S. application Ser. No. 10/207,542, filed Jul. 29, 2002 (incorporated by reference above), or, in the alternative, may be moved along the incline by the weight of the first casing string 210 upon the gripping members 20. In either instance, the incline of the bowl 25 causes the gripping members 20 to move radially toward the outer diameter of the first casing string 210 to contact the first casing string 210 and hinder further downward movement of the first casing string 210 within the wellbore 180.
After the spider 100 stops the first casing string 210 from further downward movement within the wellbore 180, the top drive 110 and elevator 200 are disengaged from the first casing string 210. The elevator 200 retrieves a second casing string 130 from its original location, such as from the rack (not shown), and connects the second casing string 130 to the top drive 110. The second casing string 130 is lowered toward the wellbore 180 substantially in line with the first casing string 210 with respect to well center to mate with the first casing string 210. Then a makeup operation is performed, and the top drive 110 may be activated so that the motor 140 rotates the second casing string 130 to threadedly connect the second casing string 130 to the first casing string 210.
The spider 100 is then unactuated again to release the gripping members 20 from the first casing string 210. Releasing the gripping members 20 causes the gripping members 20 to move radially away from the first casing string 210. The gripping members 20 may be released by actuating the piston and cylinder assembly according to the above-mentioned co-pending application. In the alternative, the gripping members 20 may be released by pulling up on the casing 130, by using an elevator for example.
Because the first casing string 210 and the second casing string 130 are now threadedly connected to one another, the elevator 200 and connection to the top drive 110 hold the entire casing string 210, 130 above the wellbore 180. The top drive 110 may again impart rotation to the casing string 210,130 while the casing string 210, 130 is simultaneously lowered, so that the drill bit (not shown) at the lower end of the first casing string 210 drills to a second depth within the formation 215. The rollers 84 are adjusted radially outward or inward to accommodate the diameter of the second casing string 140 when the second casing string 140 reaches the spider 100. The process as described above is then repeated until the desired number of casing strings is disposed within the wellbore 180 to reach the desired depth within the formation 215.
The above description of embodiments of the present invention contemplates the spider 100 being flush mounted within the rig floor 135. Alternative embodiments include the spider 100 being mounted or located above or on the rig floor 135, as with conventional spiders, or mounted or located below the rig floor 135.
Moreover, above-described embodiments include rotating the entire casing string while drilling the casing into the formation. Other embodiments of the present invention involve rotating only a portion of the casing string, for example the earth removal member (preferably a drill bit) by a mud motor or other torque-conveying device. Yet further embodiments of the present invention involve merely lowering the casing string into the formation to form a wellbore while circulating drilling fluid out from the casing string (“jetting”) without rotation of any portion of the casing string. Any combination of rotation of the casing string, rotation of a portion of the casing string, and/or jetting may be utilized in embodiments of the present invention.
Although the above discussion of embodiments of the present invention describes the spider 100 in terms of drilling with casing, the spider 100 may also be used in casing handling operations to support any type of tubular body during any wellbore operation. Specifically, the spider 100 may be utilized to support a tubular when making up and/or breaking out threadable connections between tubulars and/or lowering tubulars into the wellbore. Tubulars usable with the spider 100 of the present invention include but are not limited to drill pipe, liner, tubing, and slotted tubulars. Additionally, the spider 100 described above may be used for running casing into a previously-formed wellbore, drilling with casing, running one or more tubulars into the wellbore, forming a tubular string (e.g., by threadedly connecting tubulars), and/or connecting casing sections (preferably by threadable connection) to one another.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application is a continuation of U.S. patent application Ser. No. 10/794,800, filed Mar. 5, 2004, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/207,542 filed Jul. 29, 2002, which is herein incorporated by reference in its entirety. This application also claims benefit of U.S. Provisional Patent Application Ser. No. 60/452,154, filed on Mar. 5, 2003, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10794800 | Mar 2004 | US |
| Child | 11345066 | Feb 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10207542 | Jul 2002 | US |
| Child | 10794800 | Mar 2004 | US |
