Tubing conveyed fracturing tool and method

• US 6,776,239 B2
• Filed: 02/19/2002
• Issued: 08/17/2004
• Est. Priority Date: 03/12/2001
• Status: Expired due to Term

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: McGill, Howard L., Sheffield, Randolph J., Eslinger, David M., Hill, Stephen D., Costley, James M.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): Gay, Jennifer H
• Application Number:
  US10/078,963
• Publication Number:
  US 20020125005A1
• Time in Patent Office: 910 Days
• Field of Search: 166/281, 166/305.1, 166/308, 166/373, 166/381, 166/167, 166/382, 166/386, 166/387, 166/179, 166/118, 166/330, 166/177.5, 166/206, 166/212, 166/237, 166/240, 166/331, 166/242.7, 166/308.1
• US Class Current: 166/308.1
• CPC Class Codes: E21B 23/006 "J-slot" systems, i.e. lug and slot indexing mechanisms
• CPC Class Codes: E21B 33/124 Units with longitudinally-spaced plugs for isolating the intermediate space
• CPC Class Codes: E21B 33/1243 with inflatable sleeves
• CPC Class Codes: E21B 43/26 by forming crevices or fractures

Abstract

A tubing conveyed multi-position well treating tool having a tubular housing and a tubular inner member which are relatively positionable at “Set”, “Treat”, “Dump” and “Release” positions actuated by a mechanical indexing mechanism. The indexing mechanism is loaded by a spring, such as a compressed gas spring or mechanical spring, which urges the tubular housing away from the tubing connection of the inner tubular member, thus requiring no set-down forces for tool actuation or indexing. The treating tool is anchored within the well casing by hydraulic pressure actuated buttons, thus eliminating the typical requirement for anchoring actuation by set-down forces. The treating tool is sealed within the casing by pressure energized packers which are activated by the hydraulic pressure of fluid supplied from the tubing. The tool provides a bypass passage to allow communication of the zones above and below the tool while isolating the straddled interval to be treated.

Claims

1. A method for treating one or more zones intersected by a wellbore having a casing therein, the casing being perforated at the well depth of said one or more zones for fluid communication therewith, said method comprising:

running a treating tool having at least one hydraulic pressure responsive anchor and at least one hydraulic pressure responsive packer and at least one treating port into the well by flexible tubing conveyance to the well depth of a selected casing interval to be isolated by the packer and with said treating tool in a “

Set”

mode with said anchor element and said packer element retracted to prevent contact thereof with the casing;

causing fluid pressure responsive hydraulic energization of said anchor and said packer with pressurized treating fluid conducted through said flexible tubing for securing and sealing said treating tool with respect to the casing;

causing treating fluid flow responsive hydraulic indexing of said treating tool to a “

Treat”

mode with said treating port in fluid communication with the tubing and in communication with the selected interval; and

conducting pressurized formation treating fluid through the flexible tubing and through said treating port into the selected casing interval for treating the formation surrounding the selected casing interval.

2. The method of claim 1, further comprising:

repeating indexing said treating tool to said “

Set”

mode to relax said anchor and said packer and release said treating tool for tubing conveyance to other locations within the casing;

repeating said indexing of said treating tool to said “

Treat”

mode at the other locations; and

repeating said conducting pressurized formation treating fluid through the tubing and through said treating port for formation treating at the other locations.

3. The method of claim 1, further comprising:

maintaining continuous communication of casing sections above and below said treating tool through an unobstructed bypass passage with said treating tool in at least one tool mode.

4. The method of claim 1, further comprising:

selectively indexing said treating tool within the casing to said “

Set”

mode for de-energizing said anchor and said packer;

moving said treating tool to a different casing interval; and

repeating any selected number of times selective indexing of said treating tool at desired casing intervals to said “

Treat”

mode for treating the formation and then to said “

Set”

mode to prepare said treating tool for further movement to other selected intervals.

5. The method of claim 1, further comprising:

after treating of the formation, with treatment fluid flow generated force indexing said treating tool to a “

Dump”

mode opening at least one dump port therein, which may be selectively opened and closed, causing treatment fluid within said flexible tubing above said treating tool to be conducted through said treating tool and into the casing below said treating tool.

6. The method of claim 5, further comprising:

with said treating tool in said “

Dump”

mode causing hydraulic pressure acting on said anchor element and said packer to be trapped within said treating tool for maintaining hydraulic energization of said anchor element and said packer and maintaining said treating tool anchored and sealed within the casing;

releasing treating pressure from said selected interval to the tubing through said treating port; and

conducting tubing fluid through said treating tool into the casing below said treating tool.

7. The method of claim 6, further comprising:

from said “

Treat”

mode or said “

Dump”

mode, applying a pulling force to said treating tool via the flexible tubing for indexing said treating tool to a “

Release”

mode and venting hydraulic pressure from said anchor and said packer and releasing engagement of said anchor and said packer from the casing to free said treating tool for tubing conveyance within the casing by selective movement of the flexible tubing.

8. The method of claim 7, further comprising:

for indexing of said treating tool to said “

Release”

mode, maintaining tubing pulling force on said treating tool for sufficient duration for completion of a hydraulically controlled time delay sequence.

9. The method of claim 1, further comprising:

with treatment fluid flow generated force indexing said treating tool to a “

Dump”

mode, causing treating fluid from said tubing to displace casing fluid below said treating tool through said treating tool and into the casing above said treating tool.

10. The method of claim 1, further comprising:

with said treating tool at said “

Treat”

mode, discontinuing hydraulic fluid pressure supply to said treating tool, said hydraulic pressure acting on said anchor element and said packer being trapped within said treating tool and maintaining said anchor element and said packer in anchoring and sealing contact with the casing.

11. The method of claim 1, wherein the treating tool defines at least one dump port being selectively opened and closed, said method further comprising:

indexing said treating tool to a “

Release”

mode and discontinuing pressurized treating fluid supply through the flexible tubing to said treating tool, said “

Release”

mode venting hydraulic pressure of said treating fluid acting on said anchor and said packer to release said anchor and said packer from anchoring and sealing contact with the casing and opening said dump port to conduct treating fluid within the flexible tubing through said treating tool and into the casing below the treating tool.

12. The method of claim 11, further comprising:

with said treating tool in said “

Release”

mode displacing casing fluid below said treating tool through an unobstructed bypass passage in said treating tool and into the casing above said treating tool.

13. The method of claim 1, wherein said treating tool comprises a tubular housing supporting said anchor and said packer and an inner tubular member being telescopically movable relative to said tubular housing and a mechanism urging said inner tubular member in one axial direction relative to said tubular housing, and wherein said tubular housing and said inner tubular member define at least one setting port, at least one treating port, and at least one dump port, said method further comprising:

at said “

Set”

mode opening only said setting port for filling said treating tool and the tubing with well fluid during running of said treating tool into the casing; and

with said treating tool selectively located within the casing pumping fluid through said setting part at a rate developing sufficient differential pressure for energizing said anchor and said packer.

14. The method of claim 13, further comprising:

at said “

Treat”

mode opening said setting port for conducting pressurized treating fluid from the tubing through the treating tool to said packer for enhancing sealing contact thereof with the casing; and

closing said dump port to prevent discharge of pressurized treating fluid from said tubing into the casing below said treating tool.

15. The method of claim 1, further comprising:

indexing said treating tool to a “

Release”

mode opening said treating port for flow of fluid from the formation to the tubing to depressurize the formation after treating; and

opening a dump port in said treating tool to allow discharge of fluid from the tubing into the casing below said treating tool and to equalize pressure across said packer.

16. The method of claim 15, wherein, in said “

Release”

mode, the tubing fluid discharged into the casing below said treating tool displaces casing fluid below said tool through an unobstructed passage in said tool to the casing above said tool.

17. The method of claim 1, wherein said treating tool comprises a tubular housing and an inner tubular member being telescopically movable in one direction within said tubular housing by said tubing and a spring between said tubular housing and said inner tubular member telescopically urging said inner tubular member for movement in a second axial direction relative to said tubular housing, said indexing comprising:

lifting said inner tubular member by moving the flexible tubing upwardly;

relaxing said lifting force on said inner tubular member, said spring moving said inner tubular member downwardly relative to said tubular housing; and

selectively indexing said inner tubular member to said “

Treat”

mode and a “

Dump”

mode responsive to lifting and lowering of said inner tubular member relative to said tubular housing.

18. The method of claim 1, wherein said treating fluid is fracturing slurry.

19. A method for treating one or more zones intersected by a wellbore having a casing therein, the casing being perforated at the well depth of said one or more zones for fluid communication therewith, said method comprising:

running a treating tool having a tubular housing having a treating port and having an inner tubular member movable within the tubular housing into the well casing by tubing conveyance to the well depth of a selected interval of the casing;

actuating at least one anchor device and at least one packer device by application of treatment fluid pressure and securing and sealing said tubular housing with respect to the casing and for isolating the selected interval;

conducting pressurized formation treating fluid through the tubing and inner tubular member and through said treating port into an annulus of the selected interval between said treating tool and the well casing for treating the formation of the selected interval; and

with the treating tool in sealing relation with the casing, maintaining the casing above the treating tool in communication with the casing below the treating tool via an unobstructed bypass passage through the treating tool.

20. The method of claim 19, wherein said treating fluid is fracturing slurry.

21. A method for treating one or more zones intersected by a wellbore having a casing therein, the casing being perforated at the well depth of said one or more zones for fluid communication therewith, said method comprising:

running a treating tool into the well casing by coiled tubing conveyance to the well depth of a selected zone;

actuating at least one anchor device and at least one packer device by application of treatment fluid pressure and securing and sealing said treating tool with respect to the casing to establish an isolated section of the casing for fluid pressure induced treating activity;

applying lifting force to the coiled tubing and releasing the lifting force for spring induced force shifting said treating tool to a treating condition;

conducting pressurized formation treating fluid through the tubing and said treating tool into the isolated section of the casing for treating the formation of the selected zone;

further comprising applying lifting force to the coiled tubing in opposition to said spring induced force for shifting said treating tool from said treating condition to a dump condition permitting release of fluid within the tubing and treating tool into the casing below the treating tool, wherein, in said dump condition of the tool when the casing below the tool is filled with fluid, said fluid released into the casing below the treating tool displaces wellbore fluid below the tool through an unobstructed passage through the tool and into the wellbore above the tool.

22. The method of claim 21, further comprising:

applying lifting force to the coiled tubing and releasing the lifting force for actuating a J-slot type indexing mechanism and shifting said treating tool from said dump condition to a release condition releasing said securing and scaling of said treating tool relative to said casing to permit withdrawal of the treating tool from the casing by the tubing.

23. The method of claim 22, further comprising:

maintaining communication of casing sections above and below said treating tool in all modes of said treating tool.

24. The method of claim 21, wherein said treating fluid is fracturing slurry.

25. A coiled tubing conveyed treating tool for wells having a casing perforated at the well depth of at least one production zone, comprising:

a tubular housing having at least one pressure energized packer and at least one pressure energized anchor device for sealing and anchoring said tubular housing relative to the casing, said tubular housing having a treating port and a dump port;

an inner tubular member adapted for connection with the coiled tubing for coiled tubing conveyance within the casing and for pressurized treating fluid supply to said treating tool, said inner tubular member being movable to selected positions within said tubular housing and having at least one treating port and at least one dump port;

a spring continuously applying an urging force to said tubular housing and to said inner tubular member for moving said inner tubular member downwardly relative to said tubular housing; and

a J-slot type indexing mechanism controlling selected positioning of said tubular housing and said inner tubular member to a plurality of modes relative to one another in response to linear cycling movement of said inner tubular member relative to said tubular housing by selective application of a pulling force to said coiled tubing and said inner tubular member and by said urging force of said spring upon relaxing of said pulling force;

further comprising structure defining an unobstructed fluid communicating passage within said inner tubular element for maintaining communication of casing sections above and below the treating tool at one of said modes of said treating tool.

26. The coiled tubing conveyed treating tool of claim 25, wherein said plurality of modes comprise “

Set”

, “

Treat”

, “

Dump”

, and “

Release”

modes.

27. The coiled tubing conveyed treating tool of claim 26, further comprising a fluid filter.

28. The coiled tubing conveyed treating tool of claim 25, wherein said treating fluid supply is a fracturing fluid supply.

29. The coiled tubing conveyed treating tool of claim 25, further comprising an orifice defining a restriction in said fluid communicating passage to control the velocity of fluids flowing through said communicating passage and developing differential pressure across said orifice and a resultant force acting downwardly on said inner tubular member responsive to the flow of treatment fluid.

30. The coiled tubing conveyed treating tool of claim 25, wherein:

said tubular housing and said inner tubular member define a spring chamber having relatively movable walls defined respectively by said tubular housing and said inner tubular member; and

said spring is at least one mechanical spring located within said spring chamber and continuously urging said tubular housing away from the tubing.

31. The coiled tubing conveyed treating tool of claim 25, wherein:

said tubular housing defines a treating port and a dump port longitudinally spaced from one another; and

said inner tubular member defines at least one treating port and at least one dump port for selective registry with said treating port and said dump port of said tubular housing.

32. The coiled tubing conveyed treating tool of claim 25, further comprising:

at said “

Set”

mode a setting orifice being open permitting the tubing and said treating tool to fill with well fluid, said anchor device and said at least one pressure energized packer being inactivated to permit movement of said treating tool through the casing by the tubing and said treating and dump ports of said tubular housing and said inner tubular member being out of fluid communicating registry.

33. The coiled tubing conveyed treating tool of claim 25, further comprising:

at said “

Treat”

mode said tubular housing and said inner tubular member being positioned with said treating ports thereof in fluid communicating registry;

said dump ports of said tubular housing and said inner tubular member being positioned with said dump ports thereof out of fluid communicating registry; and

said pressure energized packer and said pressure energized anchor device being energized for releasably anchoring said treating tool within the casing and releasably sealing the treating tool with respect to the casing.

34. The coiled tubing conveyed treating tool of claim 25, further comprising:

at said “

Dump”

mode said tubular housing and said inner tubular member being positioned to establish registry of said dump ports thereof and to establish registry of said treating ports thereof thus draining fluid from the tubing and the inner tubular member and achieving equalization of pressure across said at least one packer.

35. The coiled tubing conveyed treating tool of claim 25, further comprising:

at said “

Release”

mode said tubular housing and said inner tubular member being positioned to establish registry of said dump ports thereof and to establish registry of said treating ports thereof and said at least one pressure energized packer and said pressure energized anchor device being vented to permit retraction thereof to release positions.

36. The tubing conveyed treating tool of claim 25, further comprising:

said indexing mechanism defining an indexing slot geometry establishing said “

Set”

, “

Treat”

, “

Dump” and

“

Release”

modes;

an indexing follower on one of said tubular housing and said inner tubular member being engaged within said indexing slot geometry for controlling relative positioning of said tubular housing and said inner tubular member at said “

Set”

, “

Treat”

, “

Dump” and

“

Release”

modes, said inner tubular member being selectively raised and lowered relative to said tubular housing to accomplish indexing of said tubular housing and said inner tubular member to a selected one of said “

Set”

, “

Treat”

, “

Dump” and

“

Release”

modes.

37. The tubing conveyed treating tool of claim 36, further comprising:

a hydraulically controlled time delay restricting relative movement of said tubular housing and said inner tubular member to said “

Release”

mode until pulling force on said inner tubular member has been applied for the duration of said time delay; and

said indexing mechanism permitting said “

Release”

mode to be achieved solely by pulling force on said inner tubular member via said coiled tubing and pemiitting said “

Set”

, “

Treat” and

“

Dump”

modes to be achieved by applying a pulling force to said inner tubular member followed by relaxing of the pulling force to permit downward movement of said inner tubular member relative to said tubular housing.

38. A coiled tubing conveyed treating tool for wells having a casing perforated at the well depth of at least one production zone, comprising:

a tubular housing having at least one pressure energized packer and at least one pressure energized anchor device for sealing and anchoring said tubular housing relative to the casing, said tubular housing having a treating port and a dump port;

an inner tubular member adapted for connection with tubing for tubing conveyance within the casing and for pressurized treating fluid supply to said treating tool, said inner tubular member being movable to selected positions within said tubular housing and having at least one treating port and at least one dump port, said tubular housing and said inner tubular member defining a compressed gas reservoir having relatively movable walls defined respectively by said tubular housing and said inner tubular member;

a compressed gas spring within said compressed gas reservoir continuously applying an urging force to said tubular housing and to said inner tubular member for moving said inner tubular member downwardly relative to said tubular housing; and

an indexing mechanism for selected positioning of said tubular housing and said inner tubular member to a plurality of modes relative to one another.