Not Applicable.
The present disclosure is directed generally to expandable anchoring tools used in drilling operations. Further, the present disclosure is directed to a method and apparatus for drilling a secondary borehole from an existing borehole in geologic formations. More particularly, the present disclosure relates to a relatively small diameter apparatus that can be run into a borehole through a smaller tubing or otherwise restricted section and then expanded to set within a section of larger diameter casing to perform downhole well operations.
Once a petroleum well has been drilled and cased, it is often necessary or desired to drill one or more additional wells that branch off, or deviate, from the first well. Such multilateral wells are typically directed toward different parts of the surrounding formation, with the intent of increasing the output of the well. The main well bore can be vertical, angled or horizontal. Multilateral technology can be applied to both new and existing wells.
In order to drill a new borehole that extends outside an existing cased wellbore, the usual practice is to use a work string to run and set an anchored whipstock. The upper end of the whipstock comprises an inclined face. The inclined face guides a window milling bit laterally with respect to the casing axis as the bit is lowered, so that it cuts a window in the casing. The lower end of the whipstock is adapted to engage an anchor in a locking manner that prevents both axial and rotational movement.
Multilateral technology provides operators several benefits and economic advantages. For example, multilateral technology can allow isolated pockets of hydrocarbons, which might otherwise be left in the ground, to be tapped. In addition, multilateral technology allows the improvement of reservoir drainage, increasing the volume of recoverable reserves and enhancing the economics of marginal pay zones. By utilizing multilateral technology, multiple reservoirs can be drained simultaneously. Thin production intervals that might be uneconomical to produce alone become economical when produced together with multilateral technology. Multiple completions from one well bore also facilitate heavy oil drainage.
In addition to production cost savings, development costs also decrease through the use of existing infrastructure such as surface equipment and the well bore. Multilateral technology expands platform capabilities where slots are limited and eliminates spacing problems by allowing more drain holes to be added within a reservoir. In addition, by sidetracking damaged formations or completions, the life of existing wells can be extended. Laterals may be drilled below a problem area once casing has been set, thereby reducing the risk of drilling through troubled zones. Finally, multilateral completions accommodate more wells with fewer footprints, making them ideal for environmentally sensitive or challenging areas.
Often however, a well bore is configured such that a tubular string of a smaller diameter is contained within a larger pipe string or casing, making it necessary to run well tools through the smaller diameter tubular and thereafter perform down hole operations (such as sidetracking) within the larger area provide by the larger tubular or casing. An apparatus and method are herein disclosed which allow a relatively small diameter assembly to be run into a borehole through a smaller diameter tubular or similar restriction and set in a relatively large diameter casing. Generally, such operations are known as thru tubing operation. Disadvantages of thru tubing tools known in the prior art include limited radial expansion capabilities and limited ability to securely anchor within the larger tubular diameter. It has been found that conventional thru tubing whipstock supports may be susceptible to small but not insignificant amounts of movement. Hence, it is desired to provide an anchor and whipstock apparatus that effectively prevent an anchored whipstock from moving. These disadvantages of the prior art are overcome by the present invention.
The present disclosure features a downhole expandable anchoring tool that may be used for passing through a restricted wellbore diameter while in a collapsed position and thereafter translating to an expanded position for grippingly engaging a larger wellbore diameter. The use of the expandable anchoring tool, however, is not limited to well operations below a restriction, but may be used in any type of wellbore, including but not limited to unrestricted wellbores, cased wellbores, or uncased wellbores.
An embodiment of the tool includes a body with a plurality of angled channels formed into a wall of the body and a plurality of moveable slips. The plurality of moveable slips translates along the plurality of angled channels between a collapsed position and an expanded position. The slips may include a plurality of extensions corresponding to and engaging the plurality of channels.
In one embodiment, a piston translates the plurality of slips from the collapsed position to the expanded position. The extensions and the channels comprise a drive mechanism for moving the slips between the collapsed position and the expanded position.
In another embodiment, the extensions and the channels support loading on the slips when the tool is in the expanded position. The slips are adapted to grippingly engage the wellbore in the expanded position. The expandable anchoring tool is not limited to use in a cased wellbore, but may also be used in an uncased or “open” wellbore.
In one aspect, a downhole assembly comprises a whipstock and an expandable anchoring tool connected to the whipstock, the expandable anchoring tool comprising a body including a plurality of angled channels formed into a wall thereof, and a plurality of moveable slips wherein the plurality of moveable slips translates along the plurality of angled channels between a collapsed position and an expanded position. The downhole assembly may further comprise a milling/drilling assembly removably connected to the whipstock. In one embodiment, the plurality of moveable slips of the expandable anchoring tool comprises a first pair of slips spaced apart circumferentially around the tool body and a second pair of slips spaced apart circumferentially around the tool body. The first pair of slips may be axially spaced from the second pair of slips. In various embodiments, a method comprises anchoring the downhole assembly within a well bore, and a method comprises performing a drilling operation using the downhole assembly.
In another aspect, a downhole assembly comprises a whipstock and an expandable anchoring tool connected to the whipstock, wherein the expandable anchoring tool comprises a slip housing, a first pair of slips spaced apart circumferentially around the slip housing, a second pair of slips spaced apart circumferentially around the slip housing and axially spaced from the first pair of slips, and wherein the first pair of slips and the second pair of slips translate between a collapsed position and an expanded position. In an embodiment, the downhole assembly further comprises a milling/drilling assembly removably connected to the whipstock. In another embodiment, a method comprises anchoring the downhole assembly within a well bore.
In yet another aspect, a method for performing a thru tubing operation in a well bore comprises running a downhole assembly comprising a whipstock and an expandable anchoring tool in a collapsed position through a first diameter section of the well bore, orienting the whipstock, and translating a plurality of pairs of slips of the expandable anchoring tool to an expanded position into gripping engagement with a casing lining a second diameter section of the well bore that is larger than the first diameter section, wherein the pairs of slips are axially spaced apart along the expandable anchoring tool. In an embodiment, the downhole assembly further comprises a milling/drilling assembly removably connected to the whipstock, and the method further comprises disconnecting the milling/drilling assembly from the whipstock, guiding the milling/drilling assembly along an inclined face of the whipstock into cutting engagement with the casing, and milling a window through the casing using the milling/drilling assembly. The method may further comprise drilling a secondary borehole through the window into a formation surrounding the well bore using the milling/drilling assembly. In an embodiment, the running, orienting, translating, disconnecting, guiding, milling and drilling are all performed during a single trip into the well bore.
Thus, the present apparatus and methods comprise a combination of features and advantages that overcome various problems of prior apparatus and methods. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description and by referring to the accompanying drawings.
For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
The present disclosure relates to methods and apparatus for performing drilling operations below a restriction such as tubing or casing. The methods and apparatus disclosed herein are susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the methods and apparatus with the understanding that the disclosure is to be considered representative only, and is not intended to limit the methods and apparatus to that illustrated and described herein.
The various embodiments of the expandable anchoring tool disclosed herein may be utilized in milling or sidetracking operations below a restriction. These embodiments also provide a plurality of methods for use in a drilling assembly. It is to be fully recognized that the different teachings of the embodiments disclosed herein may be employed separately or in any suitable combination to produce desired results.
It should be appreciated that the expandable anchoring tool described with respect to the figures that follow may be used in many different drilling assemblies. The following exemplary systems provide only some of the representative assemblies within which the expandable anchoring tool may be used, but these should not be considered the only assemblies. In particular, the various embodiments of the expandable anchoring tool disclosed herein may be used in any assembly requiring an expandable anchoring tool.
With reference to
These tools may be run into the wellbore using conventional techniques, including both coil tubing and drill string methods.
It should be recognized that while
One embodiment of an expandable anchoring tool is shown in
The recesses 416 further include angled channels 418 that provide a drive mechanism for the slips 420 to move radially outwardly into the expanded position of
In one embodiment, a threaded connection is provided at 456 between the slip housing 423 and the mandrel 460 and at 458 between the nose 480 and piston cylinder 435. A threaded connection is also provided between the nose 480 and the mandrel 460 at 457. The nose 480 sealingly engages the piston cylinder 435 at 405. The upper slip housing 423 sealingly engages the mandrel 460 at 462.
In the embodiment shown in
In the embodiment shown in
One embodiment of the expandable anchoring tool 400 comprises four slips 420, wherein, a first pair of slips, each approximately 180 degrees from each other, are designed to extend in a first longitudinal plane, and a second pair of slips, each approximately 180 degrees from each other, and located axially below the first pair of slips, are designed to extend in a second longitudinal plane, wherein the angle between the first longitudinal plane and the second longitudinal plane is approximately 90 degrees.
As best shown in
Once the slips are engaged with the borehole, to prevent the tool 400 from returning to a collapsed position until so desired, the tool 400 may also be provided with a locking means 720. In operation, downward movement of the piston also acts against a lock housing 721 mounted to the mandrel 460. The lock housing 721 cooperates with a lock nut 722 which interacts with the mandrel 460 to prevent release of the tool 400 when pressure is released. The inner radial surface of the lock housing 721 includes a plurality of serrations which cooperate with the inversely serrated outer surface of locking nut 722. Similarly, the outer radial surface of mandrel 460 includes serrations which cooperate with inverse serrations formed in the inner surface of locking nut 722. Thus, as the piston assembly causes the lock housing 721 to move downwardly, the locking nut 722 moves in conjunction therewith causing the inner serrations of the locking nut 722 to move over the serrations of the mandrel 460. The interacting edges of the serrations ensure that movement will only be in one direction thereby preventing the tool 400 from returning to a collapsed position.
The slip 420 is shown in isometric view to depict a front surface 521, a back surface 527, a top surface 665, a bottom surface 660, and side surfaces 528. Top surface 665 and bottom surface 660 are preferably angled to assist in returning the tool from an expanded position to a collapsed position. The slip 420 also includes extensions 650 disposed along each side 528 of slip 420. The extensions 650 may extend upwardly at an angle from the back 527 of the slip 420. The extensions 650 protrude outwardly from the slip 420 to fit within corresponding channels 418 in the recesses 416 of the slip housings, 422, 421, 423 as shown in
The expandable tool 400 may also be designed to return from an expanded position to a collapsed position. Referring to
In summary, the various embodiments of the expandable tool disclosed herein may be used as an anchoring tool below a restriction to grippingly engage a larger diameter. The various embodiments solve the problems of the prior art and include other features and advantages. Namely, the embodiments of the present expandable tool are stronger than prior art thru tubing anchoring tools. The tool also includes a novel assembly for moving the slips to the expanded position.
While various embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this disclosure. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system, apparatus and methods are possible and are within the scope of the present disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.
This is a continuation application of co-pending U.S. patent application Ser. No. 10/719,199 filed Nov. 21, 2003 and entitled “Thru Tubing Tool and Method”, which claims the benefit under U.S.C. §119(e) of U.S. Provisional Application No. 60/428,014 filed on Nov. 21, 2002 and entitled “Thru Tubing Multilateral Sidetracking System”, both hereby incorporated herein by reference for all purposes.
Number | Name | Date | Kind |
---|---|---|---|
1835227 | Lane et al. | Dec 1931 | A |
3285345 | Solum | Nov 1966 | A |
3397746 | Link | Aug 1968 | A |
3741304 | McGill | Jun 1973 | A |
4397355 | McLamore | Aug 1983 | A |
4712614 | Allwin et al. | Dec 1987 | A |
4712615 | Dockins, Jr. et al. | Dec 1987 | A |
4848462 | Allwin | Jul 1989 | A |
5318131 | Baker | Jun 1994 | A |
5566762 | Braddick et al. | Oct 1996 | A |
5678635 | Dunlap et al. | Oct 1997 | A |
5878818 | Hebert et al. | Mar 1999 | A |
6164377 | Roberts | Dec 2000 | A |
6360821 | Braddick | Mar 2002 | B1 |
7178589 | Campbell et al. | Feb 2007 | B2 |
20040149430 | Campbell et al. | Aug 2004 | A1 |
Number | Date | Country |
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0504193.4 | Jun 2005 | GB |
Number | Date | Country | |
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20070125550 A1 | Jun 2007 | US |
Number | Date | Country | |
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60428014 | Nov 2002 | US |
Number | Date | Country | |
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Parent | 10719199 | Nov 2003 | US |
Child | 11670888 | US |