SYSTEM AND METHOD FOR FORMING CAVITIES IN A WELL

Abstract

A technique is provided to form perforations in a wellbore. The formation of perforations is carefully controlled by a perforating device to create a series of sequential perforations in a desired arrangement. The perforating device is lowered to a desired location in the wellbore and then moved incrementally to enable sequential perforations in the desired arrangement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

FIG. 1 is an elevation view of a perforating string deployed in a wellbore, according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a perforating device positioned in a deviated wellbore, according to an embodiment of the present invention;

FIG. 3 is an illustration of cavities formed in a formation by the perforating device, according to an embodiment of the present invention;

FIG. 4 is an alternate embodiment of a perforating device, according to another embodiment of the present invention;

FIG. 5 is an illustration of cavities formed in a formation by the alternate perforating device, according to an embodiment of the present invention;

FIG. 6 is a cross sectional view of a multi-cycle incrementing tool, according to an embodiment of the present invention;

FIG. 7 is a schematic view of a J-slot mechanism, according to an embodiment of the present invention;

FIG. 8 is a schematic view of an alternate J-slot mechanism, according to another embodiment of the present invention;

FIG. 9 is a cross sectional view of the multi-cycle incrementing tool illustrated in FIG. 6 but shown in an extended position, according to an embodiment of the present invention; and

FIG. 10 is a front elevation view of an alternate embodiment of a perforating string, according to an embodiment of the present invention.

Claims

1. A system for making cavities in a wellbore, comprising: a perforating string sized for deployment in a wellbore, the perforating string comprising a perforating device; an anchoring mechanism to anchor the perforating device in the wellbore; and a multi-cycle incrementing tool to selectively move the perforating device over predetermined increments.

2. The system as recited in claim 1, wherein actuating the perforating device at each predetermined increment enables creation of a continuous cut in a surrounding formation.

3. The system as recited in claim 1, wherein the perforating device comprises a plurality of perforating jet nozzles.

4. The system as recited in claim 1, wherein the perforating device comprises a plurality of shaped charges.

5. The system as recited in claim 1, wherein the multi-cycle incrementing tool has a stroke selected to correspond with the size of a perforation cavity formed.

6. The system as recited in claim 5, wherein the multi-cycle incrementing tool comprises a circulation port that opens at the end of the stroke to provide a pressure indication that the multi-cycle incrementing tool has fully extended.

7. The system as recited in claim 1, further comprising an orienting device to orient the multi-cycle incrementing tool in the wellbore.

8. The system as recited in claim 7, wherein the orienting device comprises a swivel and an eccentric mass.

9. The system as recited in claim 1, further comprising a valve positioned in the perforating string to selectively allow fluid to be pressurized in the perforating string or to flow upwardly through the perforating string.

10. The system as recited in claim 1, wherein the multi-cycle incrementing tool comprises a spring that applies an internal bias and a compensating bias region fed by internal pressure to facilitate movement of spring.

11. The system as recited in claim 1, wherein the perforating string further comprises an elbow joint that places the perforating device in close proximity to a wellbore wall.

12. A method of making cavities in a wellbore, comprising: coupling a perforating device and a multi-cycle incrementing tool into a perforating string;moving the perforating device and the multi-cycle incrementing tool into a deviated wellbore; andcontrolling incremental movements of the perforating device with the multi-cycle incrementing tool.

13. The method as recited in claim 12, further comprising creating cavities in the wellbore between the incremental movements.

14. The method as recited in claim 13, wherein controlling comprises selecting a travel distance for the incremental movements such that a plurality of sequentially created cavities are linked.

15. The method as recited in claim 14, further comprising creating the plurality of sequentially created cavities generally in a longitudinal direction with respect to the deviated wellbore.

16. The method as recited in claim 13, wherein creating comprises creating cavities with a plurality of jetting nozzles.

17. The method as recited in claim 13, wherein creating comprises creating cavities with a plurality of shaped charges.

18. The method as recited in claim 12, further comprising anchoring the perforating string in the deviated wellbore during the incremental movements of the perforating device.

19. A method, comprising: creating a perforation in a wellbore with a perforating device;incrementally moving the perforating device with an incrementing tool; andforming a subsequent perforation linked with the perforation.

20. The method as recited in claim 19, wherein forming comprises forming additional perforations that are linked to create a cut in the formation surrounding the wellbore.

21. The method as recited in claim 20, further comprising cycling the perforating device through a previously perforated area to create deeper perforations.

22. The method as recited in claim 20, further comprising cycling the perforating device through a previously perforated area to treat previously made perforations.

23. The method as recited in claim 19, wherein incrementally moving comprises using a continuous J-slot incrementing tool.

24. A system for controlling a perforation operation in a wellbore, comprising: an apparatus to control the sequential formation of incrementally spaced cavities, the apparatus comprising a perforating mechanism and a continuous J-slot to control the incremental movement of the perforating mechanism.

25. The system as recited in claim 24, wherein the apparatus further comprises a spring and a compensating bias region to actuate the apparatus from a J-slot position to a next sequential J-slot position, the actuation occurring upon selective reduction of a pressure below a net bias pressure exerted by the spring and the compensating bias region.

26. The system as recited in claim 24, further comprising an anchoring mechanism.

27. The system as recited in claim 26, further comprising a swivel.

28. The system as recited in claim 27, further comprising coiled tubing to deliver the apparatus to a desired wellbore location.

29. A system for controlling a perforation operation in a wellbore, comprising: a perforating string having a perforating device and an elbow joint, the elbow joint selectively creating an angle in the perforating string to place the perforating device proximate a wellbore wall.

30. The system as recited in claim 29, wherein the elbow joint is spring biased toward a generally straight orientation.

31. The system as recited in claim 30, wherein jetting pressure is used to cause selective creation of the angle in the elbow joint.

32. The system as recited in claim 29, further comprising an apparatus to control the sequential formation of incrementally spaced cavities.