Casing conveyed well perforating apparatus and method

• US 20040206503A1
• Filed: 05/06/2004
• Published: 10/21/2004
• Est. Priority Date: 01/09/2003
• Status: Active Grant

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Bell, Matthew Robert George, Burres, Christopher, Ekelund, Aron
• Granted Patent: US 7,461,580 B2
• Time in Patent Office: Days
• US Class Current: 166/297
• CPC Class Codes: E21B 43/116 Gun or shaped-charge perforators
• CPC Class Codes: E21B 43/117 Shaped-charge perforators E21B43/118 takes precedence
• CPC Class Codes: E21B 43/1185 Ignition systems
• CPC Class Codes: E21B 43/119 Details, e.g. for locating perforating place or direction

Abstract

Disclosed is a casing conveyed perforating system and methods for externally perforating a wellbore and casing. The perforating system is attached to the outside of the casing and is conveyed along with the casing when it is inserted into the wellbore. The perforation may be accomplished using two groups of charges, which are contained in protective pressure chambers, however, may use only one group of bi-directional charges. Each pressure chamber may be positioned radially around the outside of the wellbore casing. The pressure chambers form longitudinally extending ribs, which conveniently serve to center the casing within the wellbore. One group of charges may be aimed inward in order to perforate the casing, while the other group of charges is aimed outward in order to perforate the formation.

Claims

1. An apparatus for carrying a perforating device capable of perforating a subterranean-earth formation through a wellbore, the apparatus comprising a carrier, the carrier comprising a bracket for securing the perforating device and a plurality of fasteners for securing the carrier to an object within the wellbore, at least one fastener being releasably secured to the bracket for adjusting the carder on the object.

2. The apparatus of claim 1, wherein the object comprises casing secured within the wellbore.

3. The apparatus of claim 2, further comprising another bracket for securing the perforation device, the bracket and the another bracket being joined by a support bar.

4. The apparatus of claim 3, wherein the plurality of fasteners includes at least one fastener releasably secured to the another bracket.

5. The apparatus of claim 3, wherein the plurality of fasteners includes a first set and a second set, the first set of fasteners being releasably secured to the bracket and the second set of fasteners being releasably secured to the another bracket.

6. The apparatus of claim 2, wherein the casing is perforated.

7. The apparatus of claim 1, farther comprising:

a first casing string; and

a second casing string, the carrier being positioned within the first casing string on the object, the object and the first casing string being positioned within the second casing string, the perforating device causing the perforation of the subterranean-earth formation through the first casing string, the second casing string, and the wellbore.

8. The apparatus of claim 1, wherein each fastener comprises a pivotal pin releasably secured through a portion of the bracket and the fastener.

9. The apparatus of claim 3, wherein the bracket and the another bracket each include a first end and a second end, the first end and the second end each comprising a groove for receipt of one of the plurality of fasteners, each groove and each fastener comprising a plurality of interlocking teeth for adjusting the carrier on the object.

10. The apparatus of claim 2, wherein the casing is expandable.

11. An apparatus for perforating a subterranean-earth formation through a wellbore lined with perforated casing, the apparatus comprising a gun assembly secured to an exterior surface of the casing, the gun assembly comprising a charge positioned to form an opening in the formation for fluid communication between the formation and an area inside the casing, the opening defining a flow path substantially non-perpendicular to a plane that is substantially perpendicular to a flow path defined by an opening in the casing.

12. The apparatus of claim 11, wherein the charge is linear.

13. An apparatus for transferring ballistic energy from one perforating device to another perforating device over a casing joint, the apparatus comprising:

a first bracket secured to a casing segment;

a second bracket secured to another casing segment; and

a chamber secured between the first bracket and the second bracket, the chamber comprising a first ballistic charge, a second ballistic charge, and a medium for transferring the ballistic energy from the first ballistic charge to the second ballistic charge.

14. The apparatus of claim 13, further comprising a support bar for securing the chamber.

15. The apparatus of claim 14, further comprising a plurality of fasteners for releasably securing the first bracket to the casing segment and the second bracket to the another casing segment.

16. The apparatus of claim 15, wherein the plurality of fasteners includes a first set and a second set, the first set of fasteners releasably secured to the first bracket and the second set of fasteners releasably secured to the second bracket.

17. The apparatus of claim 15, wherein the first bracket and the second bracket each comprise a first end and a second end, the first end and the second end each comprising a groove for receipt of one of the plurality of fasteners, each groove and each fastener comprising a plurality of interlocking teeth for adjusting the carrier on the casing segment and the another casing segment.

18. The apparatus of claim 13, further comprising a carrier for each perforating device, each carrier comprising a bracket for securing a respective perforating device and a plurality of fasteners for securing the carrier to at least one of the casing segment and the another casing segment, at least one fastener being releasably secured to the bracket for adjusting the carrier.

19. The apparatus of claim 18, wherein each perforating device comprises a sealed pressure chamber for housing a gun assembly, the pressure chamber comprising an inside surface, an outside surface and two ends, each end sealed by an end cap.

20. The apparatus of claim 19, wherein each pressure chamber and the chamber are longitudinally aligned and substantially equidistant from a common axis of the casing segment and the another casing segment.

21. The apparatus of claim 20, wherein the casing segment and the another casing segment are joined by a threaded coupling.

22. The apparatus of claim 13, wherein the medium for transferring the ballistic energy comprises a detonating cord.

23. A firing head for activating a perforating device capable of perforating a subterranean-earth formation through a wellbore, the perforating device comprising a plurality of gun assemblies, each gun assembly comprising a plurality of explosive charges, the firing head comprising.

a body comprising a plurality of longitudinal passages therethrough, at least one passage for receipt of a tubular object;

a plurality of donor charges each donor charge secured within a respective longitudinal passage and positioned near a respective gun assembly; and

a firing assembly for detonating the plurality of donor charges, the detonation of each donor charge creating ballistic energy that is transferred to a respective gun assembly for detonating the plurality of explosive charges contained therein.

24. The apparatus of claim 23, wherein each gun assembly is contained within a sealed pressure chamber for isolating the gun assembly from the wellbore.

25. The apparatus of claim 23, wherein the plurality of explosive charges comprise a receiver charge coupled to a booster charge, the receiver charge being positioned near a respective donor charge for accepting the ballistic energy and transferring the ballistic energy to the booster charge.

26. The apparatus of claim 23, further comprising a nipple for securing each donor charge within the respective longitudinal passage, each nipple being threadably connected to one end of the respective longitudinal passage.

27. The apparatus of claim 23, wherein the firing assembly is activated by a detonation signal from a surface of the formation, the detonation signal selected from the group of signals comprising:

electronic, electromagnetic, acoustic, seismic, hydraulic, optical or radio frequency.

28. The apparatus of claim 27, further comprising a shearable plug positioned through a wall of the tubular object and the body of the firing head, the firing assembly being activated by hydraulic pressure from inside the tubular object when a force plug shears the shearable plug, creating a fluid path between the tubular object and the firing assembly.

29. The apparatus of claim 27, wherein the detonation signal is transmitted from the surface of the formation to the firing assembly through one of at least a continuous and noncontinuous transmission medium.

30. The apparatus of claim 29, wherein the firing assembly comprises a transmitter/receiver for receiving the detonation signal from the surface and transmitting information back to the surface from the firing assembly.

31. The apparatus of claim 30, wherein the firing assembly comprises an isolating device positioned between the transmission medium and the transmitter/receiver for isolating the transmission medium from conductive fluids entering the fusing assembly.

32. The apparatus of claim 31, wherein the firing assembly comprises a processor for interpreting the detonation signal.

33. The apparatus of claim 32, wherein the firing assembly comprises a detonator for each donor charge, the detonator being electronically coupled to the transmitter/receiver.

34. The apparatus of claim 33, wherein the detonator is an exploding bridge wire device.

35. The apparatus of claim 33, wherein each donor charge may be selectively activated.

36. The apparatus of claim 35, wherein each donor charge may be simultaneously activated.

37. An apparatus for transferring ballistic energy from a perforating device to another perforating device, the perforating device and the another perforating device each comprising a gun assembly, each gun assembly comprising a plurality of explosive charges, the apparatus comprising:

a body comprising a plurality of longitudinal passages therethrough₇ at least one passage for receipt of a tubular object;

a donor charge secured within one of the plurality of longitudinal passages, the donor charge being positioned near the gun assembly of the perforating device;

another donor charge secured within at )east one of the one of the plurality of longitudinal passages and another one of the plurality of longitudinal passages, the another donor charge being positioned near the gun assembly of the another perforating device; and

a detonating medium for transferring the ballistic energy from the donor charge to the another donor charge.

38. The apparatus of claim 37, wherein each gun assembly is secured within a sealed chamber.

39. The apparatus of claim 37, wherein each plurality of explosive charges comprises a receiver charge and a booster charge.

40. The apparatus of claim 39, wherein the donor charge, the another donor charge, the receiver charge and the booster charge are bi-directional.

41. The apparatus of claim 40, further comprising a nipple for securing the donor charge within the one of the plurality of longitudinal passages and another nipple for securing the another donor charge within at least one of the one of the plurality of longitudinal passages and the another one of the plurality of longitudinal passages.

42. The apparatus of claim 40, wherein donor charge is positioned about one-half inch (½

″

) from at least one of the booster charge and the receiver charge for the perforating device.

43. The apparatus of claim 40, wherein the another donor charge is positioned about one-half inch (½

″

) from at least one of the receiver charge and the booster charge for the another perforating device.

44. The apparatus of claim 37, wherein the detonating medium comprises a detonating cords

45. The apparatus of claim 37, wherein the donor charge is positioned opposite the another donor charge relative to the detonating medium in the one of the plurality of longitudinal passages.

46. The apparatus of claim 37, wherein the another donor charge is positioned in the another one of the plurality of longitudinal passages on the same side of the detonating medium as the donor charge.

47. An apparatus for carrying a perforating device capable of perforating a subterranean-earth formation through a wellbore, the apparatus comprising:

a tubular member, the tubular member comprising an exterior surface; and

a bracket secured to the exterior surface of the tubular member for securing the perforating device.

48. The apparatus of claim 47, further comprising another bracket for securing the perforating device, the bracket and the another bracket being integral with the tubular member.

49. The apparatus of claim 48, wherein the tubular member is expandable.

50. A method for perforating a subterranean-earth formation near a wellbore lined with casing, comprising the steps of:

positioning a charge between the casing and the formation to form an opening in the formation for fluid communication between the formation and an area inside the casing, the opening in the formation defining a flow path substantially non-perpendicular to a plane that is substantially perpendicular to a flow path defined by an opening in the casing; and

detonating the charge.

51. The method of claim 50, further comprising the step of detonating another charge to form the opening in the casing.

52. The method of claim 50, wherein the charge is positioned to form the opening in the formation without forming the opening in the casing.

53. A method for perforating a subterranean-earth formation near a wellbore lined with casing comprising the steps of:

positioning a charge between the casing and the formation to form an opening in the formation for fluid communication between the formation and an area inside the casing, the opening in the formation defining a substantially longitudinal flow path that is substantially aligned with a longitudinal axis of the casing; and

detonating the charge.

54. The method of claim 53, wherein the opening in the formation is substantially linear.

55. A method for perforating a subterranean-earth formation near a wellbore lined with casing, comprising the steps of:

positioning a charge between a perforated segment of the casing and the formation to form an opening in the formation for fluid communication between the formation and an area inside the casing; and

detonating the charge.

56. A method for perforating a subterranean-earth formation near a wellbore lined with casing, comprising the steps of:

positioning a charge between the casing and the formation to form an opening in the formation for fluid communication between the formation and an area inside the casing;

expanding the casing to radially move the charge toward the formation; and

detonating the charge.

57. The method of claim 56, further comprising the steps of:

positioning another charge between the casing and the formation to form an opening in the casing for fluid communication between the formation and the area inside the casing; and

detonating the another charge.

58. The method of claim 56, wherein the charge is moved to a position against the formation.

59. A method for transferring ballistic energy from a perforating device to another perforating device, the perforating device and the another perforating device each comprising a plurality of gun assemblies, each gun assembly comprising a plurality of explosive charges, the method comprising the steps of:

detonating one of the plurality of explosive charges in each gun assembly of the perforating device; and

transferring ballistic energy from at least one of the one of the plurality of explosive charges in each gun assembly of the perforating device to at least one of another one of the plurality of explosive charges in each gun assembly of the perforating device and one of the plurality of explosive charges in each gun assembly of the another perforating device.