Coiled tubing drilling with supercritical carbon dioxide

• US 6,347,675 B1
• Filed: 03/09/2000
• Issued: 02/19/2002
• Est. Priority Date: 03/15/1999
• Status: Expired due to Term

• Current Assignee: Tempress Technologies, Inc. (Oil States International Incorporated)
• Original Assignee: Tempress Technologies, Inc. (Oil States International Incorporated)
• Inventors: Kollé, Jack J.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): Walker, Zakiya
• Application Number:
  US09/521,787
• Time in Patent Office: 712 Days
• Field of Search: 175/65-69, 175/71, 175/205, 175/206, 175/212, 175/117, 166/401, 166/402, 507/102
• US Class Current: 175/69
• CPC Class Codes: C09K 8/38 Gaseous or foamed well-drilling compositions
• CPC Class Codes: E21B 21/063 by separating components
• CPC Class Codes: E21B 21/16 using gaseous fluids E21B21/14 takes precedence
• CPC Class Codes: Y02P 20/54 using solvents, e.g. supercritical solvents or ionic liquids

Abstract

A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO₂) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO₂ to exist as a supercritical fluid. Supercritical carbon dioxide (SC—CO₂) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC—CO₂ provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC—CO₂ within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC—CO₂ much more effective than water jet erosion. SC—CO₂ jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO₂ to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO₂ can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

Claims

1. A method for using at least one of a supercritical fluid and a dense gas to increase an efficiency of a drilling operation, comprising the steps of:

(a) providing a material that exists in one of a supercritical phase state and a dense gas phase state at a temperature and a pressure associated with a drill site where the drilling operation is performed;

(b) supplying the material to the drill site;

(c) exposing the material that is being supplied to a temperature and a pressure that causes at least a portion of the material being supplied to change its phase state to one of a supercritical fluid and a dense gas;

(d) ejecting a fluid stream of said material being supplied onto said drill site; and

(e) performing said drilling operation, said material that is ejected increasing an efficiency of said drilling operation.

2. The method of claim 1, further comprising at least one of the steps of:

(a) using said at least the portion of said material to provide cooling to a drilling apparatus;

(b) using said at least the portion of said material to remove debris generated by said drilling operation from said drill site; and

(c) using said at least the portion of said material to erode said drill site.

3. The method of claim 1, further comprising the step of providing a drilling apparatus that comprises a member adapted to apply at least one of a mechanical cutting action, a mechanical grinding action, and a mechanical shearing action to said drill site, further comprising the step of positioning said member of the drilling apparatus in contact with said drill site.

4. The method of claim 1, further comprising the steps of:

(a) providing a fluid jet of said material; and

(b) directing said fluid jet at the drill site.

5. The method of claim 1, further comprising the step of controlling at least one of said temperature and said pressure, to ensure that said at least the portion of said material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state.

6. The method of claim 1, wherein said material includes one of:

(a) carbon dioxide;

(b) natural gas;

(c) a mixture of carbon dioxide and natural gas;

(d) a mixture of carbon dioxide, natural gas and water;

(e) a mixture of carbon dioxide and water;

(f) a mixture of carbon dioxide and at least one component of natural gas; and

(g) a mixture of carbon dioxide, water, and at least one component of natural gas.

7. The method of claim 6, wherein the material contains a foaming agent.

8. The method of claim 1, wherein the step of performing the drilling operation comprises the step of removing scale deposits from a surface of said drill site.

9. The method of claim 1, further comprising the step of forming an opening in said drill site.

10. The method of claim 1, wherein the drill site comprises a plurality of pores, and the step of ejecting said fluid stream of the material comprises the step of causing at least a portion of said material existing in one of a supercritical phase state and a dense gas phase state to penetrate into said pores.

11. The method of claim 10, wherein the drill site comprises one of rock and concrete.

12. The method of claim 1, wherein the drill site comprises a geological formation.

13. The method of claim 12, wherein the geological formation is at a temperature of at least 31°

C .

14. The method of claim 12, wherein the geological formation is associated with at least one of a petroleum resource, a natural gas resource, and a geothermal resource.

15. The method of claim 12, wherein the drill site includes an existing well for the extraction of at least one of a petroleum resource, a natural gas resource, and a geothermal resource.

16. The method of claim 15, further comprising the step of providing a drill apparatus that comprises a coiled tube adapted to fit within the existing well.

17. The method of claim 16, wherein the coiled tube comprises a downhole motor and a drill head driven by the downhole motor, and wherein the step of performing the drilling operation comprises the step of energizing said downhole motor to cause the drill head to be driven.

18. The method of claim 17, wherein the downhole motor comprises one of a turbine motor, a jet rotor, a progressive cavity displacement motor, a rotary-percussive hammer, and a vane motor.

19. The method of claim 17, wherein the drill head comprises one of a jet erosion bit, a mechanical bit, and a jet-assisted mechanical bit.

20. The method of claim 17, wherein the step of energizing the downhole motor comprises the step of causing said material to flow through said coiled tube and through said downhole motor.

21. The method of claim 17, further comprising the step of providing a second material that is a fluid, and wherein the step of energizing the downhole motor comprises the step of causing said second material to flow through said coiled tube and through said downhole motor.

22. The method of claim 15, wherein the existing well comprises a surface choke manifold, and further comprising the step of using the surface choke manifold to control said pressure to ensure that at least the portion of said material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state.

23. The method of claim 15, further comprising the steps of:

(a) providing a drilling mud; and

(b) filling the existing well with the drilling mud to control said pressure, to ensure that at least a portion of said material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state.

24. The method of claim 15, wherein the existing well comprises a surface choke manifold, further comprising the steps of:

(a) providing a source of drilling mud; and

(b) controlling the pressure to ensure that at least a portion of said material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state by carrying out at least one of the steps of;

(i) using the surface choke manifold to control the pressure; and

(ii) filling the existing well with drilling mud to control the pressure.

25. The method of claim 24, wherein the step of controlling the pressure comprises the step of causing said pressure to exceed 5 MPa.

26. The method of claim 24, wherein the step of controlling said pressure comprises the step of causing said associated pressure to exceed 7.4 MPa.

27. The method of claim 15, further comprising the steps of:

(a) providing a material recovery vessel in fluid communication with said existing well; and

(b) collecting said material after performing said drilling operation, so that said material can be reused.

28. A method for using at least one of a supercritical fluid and a dense gas to perform maintenance within an existing borehole formed by a drilling apparatus within a substrate of a geological formation, comprising the steps of:

(a) providing a material that exists in one of a supercritical phase state and a dense gas phase state at a temperature and a pressure within the existing borehole;

(b) ejecting a fluid stream of said material, said temperature and pressure causing at least a portion of said material in said fluid stream to exist in one of a supercritical phase state and a dense gas phase state; and

(c) performing the maintenance in the existing borehole with said at least the portion of the material.

29. The method of claim 28, wherein the step of performing the maintenance comprises at least one of the steps of:

(a) removing scale from within said existing borehole; and

(b) drilling an additional borehole, said additional borehole being in fluid communication with the existing borehole.

30. The method of claim 29, wherein the step of drilling an additional borehole comprises the step of drilling a lateral drainage well.

31. The method of claim 28, wherein the existing borehole comprises surface equipment, and the drilling apparatus comprises a coiled tube adapted to enter the existing borehole through the surface equipment, further comprising the steps of:

(a) passing said coiled tube through said surface equipment; and

(b) advancing said coiled tube into said existing borehole until a desired location is reached to perform the maintenance.

32. The method of claim 31, further comprising the step of:

(a) providing a downhole motor and a drill head adapted to be driven by said downhole motor, said drill head being disposed at a distal end of the coiled tube; and

(b) energizing said downhole motor to drive said drill head.

33. The method of claim 32, wherein the downhole motor comprises one of a turbine motor, a jet rotor, a progressive cavity displacement motor, a vane motor, and a rotary percussive hammer.

34. The method of claim 32, wherein the drill head comprises ajet erosion bit through which the fluid stream of the material is ejected, further comprising the step of positioning said jet erosion bit adjacent to said substrate, such that said fluid stream impacts said substrate, thereby causing said substrate to erode.

35. The method of claim 32, wherein the drill head comprises a mechanical bit adapted to apply at least one of a cutting action, a grinding action, and a shearing action to said substrate, further comprising the steps of:

(a) contacting said substrate with the mechanical bit; and

(b) using the material to carryout at least one of the steps of;

(i) cooling said drill head; and

(ii) removing debris from an area of the substrate adjacent to said drill head.

36. The method of claim 32, wherein the drill head comprises a jet assisted mechanical bit that is adapted to apply at least one of a cutting action, a grinding action, a shearing action and a jet eroding action to said substrate, further comprising the step of causing the jet assisted mechanical bit to contact said substrate;

and wherein the step of ejecting said fluid stream comprises at least one of the steps of;

(a) cooling said drill head;

(b) removing debris from the area of the substrate adjacent to said drill head; and

(c) eroding said substrate.

37. The method of claim 32, wherein the step of energizing the downhole motor comprises the step of causing said material to flow through said coiled tube and through said downhole motor.

38. The method of claim 32, further comprising the step of providing a second material that is a fluid;

wherein the step of energizing the downhole motor comprises the step of causing said second material to flow through said coiled tube and through said downhole motor.

39. The method of claim 31, wherein the surface equipment comprises a surface choke manifold, further comprising the step of using the surface choke manifold to control the pressure so as to ensure that at least the portion of said material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state.

40. The method of claim 31, further comprising the steps of:

(a) providing a source of drilling mud; and

(b) filling the existing borehole with drilling mud to control the pressure to ensure that at least the portion of the material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state.

41. The method of claim 31, surface equipment includes a surface choke manifold, further comprising the steps of:

(a) providing drilling mud; and

(b) controlling the pressure to ensure that at least the portion of the material in said fluid stream exists in said one of the supercritical phase state and the dense gas phase state by carrying out at least one of the steps of;

(i) using the surface choke manifold to control the pressure; and

(ii) filling the existing borehole with drilling mud to control the pressure.

42. The method of claim 41, wherein the step of controlling the pressure further comprises the step of causing said pressure to exceed 5 MPa.

43. The method of claim 41, wherein the step of controlling said pressure comprises the step of causing said pressure to exceed 7.4 MPa.

44. The method of claim 28, wherein the material includes one of carbon dioxide, methane, natural gas, a mixture of carbon dioxide and methane, and a mixture of carbon dioxide and natural gas.

45. The method of claim 28, wherein the substrate comprises a plurality of pores, and the step of ejecting said fluid stream of said material comprises the step of causing at least the portion of the material existing in said one of the supercritical phase state and the dense gas phase state to penetrate into said pores.

46. The method of claim 28, further comprising the steps of:

(a) providing a storage vessel for spent material, said storage vessel being in fluid communication with said substrate; and

(b) collecting said material after it is used for the step of performing maintenance, so that said material can be reused.

47. The method of claim 28, further comprising the step of venting said material to the atmosphere after the material is used for performing maintenance.

48. A system for using one of a supercritical fluid and a dense gas to perform maintenance related to an existing borehole within a geological formation, comprising:

(a) a supply source for a material that exists in one of a supercritical phase state and a dense gas phase state at a temperature and a pressure found within the existing borehole;

(b) a drillstring having a distal end and a proximal end, said distal end being in fluid communication with said supply source, a tool defining a fluid outlet being mounted on the proximal end, said drillstring defining a fluid path from said supply source to said fluid outlet; and

(c) means for controlling at least one of a temperature and a pressure at said fluid outlet, so that the material supplied through the fluid outlet exists in at least one of a supercritical phase and the dense gas phase, the material being employed to perform maintenance in the existing borehole.

49. The system of claim 48, wherein the drillstring further comprises a coiled tube.

50. The system of claim 48, wherein said drillstring further comprises a downhole motor, said downhole motor being disposed within said fluid path.

51. The system of claim 50, wherein said downhole motor comprises one of a turbine motor, a jet rotor, a progressive cavity displacement motor, a rotary percussive hammer, and a vane motor.

52. The system of claim 48, wherein the tool comprises one of a jet erosion bit, a jet assisted mechanical bit, and a mechanical bit.

53. The system of claim 48, wherein the tool comprises a jet erosion bit with a non rotating gage collar.

54. The system of claim 48, wherein the material includes one of:

(a) carbon dioxide;

(b) natural gas;

(c) a mixture of carbon dioxide and natural gas;

(d) a mixture of carbon dioxide, natural gas and water;

(e) a mixture of carbon dioxide and water;

(f) a mixture of carbon dioxide and at least one component of natural gas; and

(g) a mixture of carbon dioxide, water, and at least one component of natural gas.

55. The system of claim 48, further comprising:

(a) a supply source of a second material that is a fluid;

(b) a second fluid path within said drillstring, said second fluid path being in fluid communication with said supply source of said second material at said distal end of said drillstring; and

(c) a downhole motor disposed within said second fluid path, said downhole motor being drivingly connected to said tool and actuated by a flow of the second material through the second fluid path.

56. The system of claim 55, wherein said second material comprises one of drilling mud, water, and brine.

57. The system of claim 48, further including a storage vessel for spent material, said storage vessel being in fluid communication with said fluid outlet to enable spent material to be collected for reuse.

58. The system of claim 48, wherein said means comprises a choke manifold, said choke manifold being disposed at a distal end of said borehole, in fluid communication with said fluid path, and adapted to control said pressure within said borehole.

59. The system of claim 48, wherein said tool further comprises a plurality of radially oriented fluid outlets, each adapted to direct ajet of fluid toward a wall of said borehole, to remove scale from said wall.

60. The system of claim 59, wherein said plurality of radially oriented fluid outlets are disposed relative to one another so as to substantially eliminate side thrust on said tool.

61. The system of claim 59, wherein said plurality of radially oriented fluid outlets are offset from an axis of rotation of said tool, to provide rotational torque to said tool.

62. A system for using one of a supercritical fluid and a dense gas to perform maintenance related to an existing borehole within a geological formation, comprising:

(a) a supply source for a material that exists in one of a supercritical phase state and a dense gas phase state at a temperature and a pressure found within the existing borehole;

(b) a drillstring having a distal end and a proximal end, said distal end being in fluid communication with said supply source;

(c) a downhole motor in fluid communication with said drillstring, such that a fluid moving through said drillstring into said downhole motor drives said downhole motor;

(d) a tool defining a fluid outlet mounted on the proximal end of said drillstring, such that said tool is in fluid communication with said drillstring, said tool being drivingly rotated by said downhole motor; and

(e) means for controlling at least one of a temperature and a pressure at said fluid outlet, so that the material supplied through the fluid outlet exists in at least one of the supercritical phase and the dense gas phase, the material being employed to perform maintenance in the existing borehole.

63. The system of claim 62, wherein said means comprises a choke manifold, said choke manifold being disposed at a distal end of said borehole, in fluid communication with said fluid path, and adapted to control said pressure within said borehole.

64. The system of claim 62, wherein said means comprises a drilling mud supply source, said drilling mud supply source being in fluid communication with said fluid path, and adapted to control said pressure within said borehole by providing drilling mud to form a mud cap within said borehole.

65. The system of claim 62, wherein said tool further comprises a plurality of radially oriented fluid outlets, each adapted to direct a jet of fluid toward a wall of said borehole, to remove scale from said wall.

66. The system of claim 65, wherein said plurality of radially oriented fluid outlets are disposed relative to one another so as to substantially eliminate side thrust on said tool.

67. The system of claim 65, wherein said plurality of radially oriented fluid outlets are offset from an axis of rotation of said tool to provide rotational torque to said tool.