METHOD AND APPARATUS FOR DETERMINING DOWNHOLE PRESSURES DURING A DRILLING OPERATION

• US 20040025583A1
• Filed: 12/19/2002
• Published: 02/12/2004
• Est. Priority Date: 08/15/2002
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Fisseler, Patrick J., Palmer, Thomas W. II, Zazovsky, Alexander, Follini, Jean-Marc, Kurkjian, Andrew L.
• Granted Patent: US 7,062,959 B2
• Time in Patent Office: Days
• US Class Current: 73/152.51
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: E21B 49/087 Well testing, e.g. testing for reservoir productivity or formation parameters

Abstract

A method and apparatus is provided to determine downhole pressures, such as annular pressure and/or pore pressure, during a drilling operation. A downhole drilling tool includes at least one conduit and a corresponding gauge. The conduit is positioned in the downhole tool and has an opening adapted to receive downhole fluids. The conduit is positionable in fluid communication with one of the wellbore and the formation whereby pressure is equalized therebetween. The gauge is provided for measuring the pressure in the conduit.

Claims

1. An apparatus for measuring downhole pressure, the apparatus disposed in a downhole drilling tool positionable in a wellbore having an annular pressure therein, the wellbore penetrating a subterranean formation having a pore pressure therein, the apparatus comprising:

a conduit positioned in the downhole tool, the conduit having an opening adapted to receive downhole fluids, the conduit positionable in fluid communication with one of the wellbore and the formation whereby pressure is equalized therebetween; and

a gauge for measuring pressure in the conduit.

2. The apparatus of claim 1, further comprising a pad positioned about the opening of the conduit.

3. The apparatus of claim 2, wherein the pad has an outer surface adapted to conform to the sidewall of the wellbore.

4. The apparatus of claim 3 wherein the pad is positionable in sealing engagement with the sidewall of the wellbore.

5. The apparatus of claim 2 wherein the pad is circular.

6. The apparatus of claim 2 wherein the pad is positionable within one of a stabilizer blade, under reamer and a wear ring.

7. The apparatus of claim 2 wherein the pad is extendable from the drilling tool for engagement with the wellbore wall.

8. The apparatus of claim 2 wherein the drilling tool includes one of a stabilizer blade, under reamer, wear ring and combinations thereof, and wherein the one of the stabilizer blade, under reamer and wear ring extends further from the downhole drilling tool than the pad.

9. The apparatus of claim 1, wherein the drilling tool has a protrusion extending therefrom, the protrusion defining a contact surface positionable adjacent the sidewall of the wellbore, the opening of the conduit extending through the contact surface.

10. The-apparatus of claim 9 wherein the protrusion forms at least a portion of one of a stabilizer blade, under reamer and a wear ring.

11. The apparatus of claim 9 wherein the protrusion forms at least a portion of a bottom hole assembly connected to the downhole drilling tool.

12. The apparatus of claim 9 wherein the protrusion is extendable from the drilling tool for engagement with the wellbore wall.

13. The apparatus of claim 1 wherein the conduit is positioned in a drill collar, the drill collar connectable to the downhole drilling tool.

14. The apparatus of claim 1 wherein the conduit is positioned along the downhole tool at one of adjacent the bit, a distance from the bit and combinations thereof.

15. The apparatus of claim 1 further comprising a plurality of conduits and corresponding gauges.

16. The apparatus of claim 15 wherein at least one of the plurality of conduits is positionable in fluid communication with the wellbore and wherein the corresponding gauge measures the annular pressure.

17. The apparatus of claim 15 wherein at least one of the conduits is positioned in fluid communication with the formation whereby pressure is equalized therebetween and wherein the a gauge measures the pore pressure.

18. The apparatus of claim 17 wherein at least one of the plurality of conduits is positionable in fluid communication with the wellbore and wherein the corresponding gauge measures the annular pressure.

19. The apparatus of claim 1 further comprising a pretest piston operatively connected to the conduit.

20. The apparatus of claim 1 further comprising an actuator capable of selectively extending the conduit from the downhole tool.

21. A downhole drilling tool capable of measuring downhole pressures during a drilling operation, the downhole drilling tool positionable in a wellbore having an annular pressure therein, the wellbore penetrating a subterranean formation having a pore pressure therein, comprising:

a bit;

a drill string;

at least one drill collar connected to the drill string, the drill collar having a cavity therein, the drill collar positionable within the wellbore such that the cavity is in fluid communication with one or the formation and the wellbore whereby pressure is equalized therebetween; and

a gauge for measuring pressure of the fluid in the cavity whereby the one of the annular and the pore pressure is determined.

22. The apparatus of claim 21, wherein the drill collar has an outer surface adapted to conform to the sidewall of the wellbore.

23. The apparatus of claim 22 wherein at least a portion of the outer surface of the drill collar is positionable in sealing engagement with the sidewall of the wellbore.

24. The apparatus of claim 21, wherein the drill collar has a protrusion extending from the drilling tool, the protrusion defining a contact surface positionable adjacent the sidewall of the wellbore.

25. The apparatus of claim 24 wherein the protrusion forms at least a portion of one of a stabilizer blade, under reamer and a wear ring.

26. The apparatus of claim 24 wherein the protrusion is one of a stabilizer blade, under reamer and a wear ring.

27. The apparatus of claim 26 wherein the protrusion is extendable from the drill collar for engagement with the sidewall of the wellbore.

28. The apparatus of claim 21 wherein the drill collar is a bottom hole assembly connected to the downhole drilling tool.

29. The apparatus of claim 21 wherein the drill collar has a plurality of cavities and corresponding gauges.

30. The apparatus of claim 29 wherein at least one of the plurality of cavities is in fluid communication with the wellbore.

31. The apparatus of claim 21 wherein the apparatus comprises a plurality of drill collars with corresponding cavities and gauges.

32. The apparatus of claim 21 wherein the drill collar is positionable along the downhole tool with the cavity at one of adjacent the bit, a distance from the bit and combinations thereof.

33. The apparatus of claim 21, further comprising a pad positioned about the opening of the cavity.

34. The apparatus of claim 33, wherein the pad has an outer surface adapted to conform to the sidewall of the wellbore.

35. The apparatus of claim 33 wherein the pad is positionable in sealing engagement with the sidewall of the wellbore.

36. The apparatus of claim 33 wherein the pad is circular.

37. The apparatus of claim 33 wherein the pad is positionable within one of a stabilizer blade, under reamer and a wear ring.

38. The apparatus of claim 33 wherein the pad is extendable from the drilling tool for engagement with the wellbore wall.

39. The apparatus of claim 38 further comprising an actuator for selectively extending the pad from the drill collar.

40. The apparatus of claim 33 wherein the drilling tool includes one of a stabilizer blade, under reamer, wear ring and combinations thereof, and wherein the one of the stabilizer blade, under reamer and wear ring extends further from the downhole drilling tool than the pad.

41. The apparatus of claim 21 wherein the drill collar is positioned in non-engagement with the wellbore wall such that the fluid in the cavity is in fluid communication with the wellbore whereby pressure is equalized therebetween and wherein the a gauge for measures the annular pressure.

42. The apparatus of claim 21 further comprising a pretest piston operatively connected to the cavity.

43. The apparatus of claim 21 wherein the drill collar is positioned in engagement with the wellbore wall such that the fluid in the cavity is in fluid communication with the formation whereby pressure is equalized therebetween and wherein the a gauge measures the pore pressure.

54. The method of claim 42 wherein a pretest piston is operatively connected to the conduit, the method further comprising performing a pretest.

44. A method of measuring downhole pressures during a drilling operation in a wellbore having an annular pressure therein, the wellbore penetrating a formation having a pore pressure therein, the method comprising:

positioning a downhole drilling tool in a wellbore, the downhole tool comprising a conduit and a gauge, the conduit having an opening adapted to receive downhole fluids, the gauge operatively connected to the conduit;

positioning the conduit in fluid communication with one of the formation and the wellbore such that pressure is equalized therebetween; and

measuring the pressure in the conduit.

45. The method of claim 44 further comprising the step of positioning an outer surface of the downhole tool adjacent the sidewall of the wellbore, the opening of the conduit extending through the outer surface of the downhole tool.

46. The method of claim 45 wherein the step of positioning comprises extending at least a portion of the outer surface adjacent the sidewall of the wellbore.

47. The method of claim 45 wherein the step of positioning comprises positioning the outer surface in sealing engagement with the sidewall of the wellbore.

48. The method of claim 45 wherein the conduit is in fluid communication with the and the pressure measured is the pore pressure.

49. The method of claim 44 further comprising the step of positioning an outer surface of the downhole tool in non-engagement with the sidewall of the wellbore, the opening of the conduit extending through the outer surface of the downhole tool.

50. The method of claim 49 wherein the conduit is in fluid communication with the wellbore and the pressure measured is the annular pressure.

51. The method of claim 44 wherein the downhole tool comprises multiple conduits and corresponding gauges.

52. The method of claim 51 further comprising comparing the pressures in the conduits.

53. The method of claim 52 further comprising analyzing the pressures.

55. An apparatus for measuring downhole pressure, the apparatus comprising:

a first conduit in a protruding portion of the drilling tool, the protruding portion positionable adjacent a sidewall of the wellbore such that fluid communication is established between the first conduit and one of the formation and the wellbore and pressure equalization occurs therebetween;

a second conduit in a non-protruding portion of the drilling tool, the non-protruding portion positionable in non-engagement with the sidewall of the wellbore such that fluid communication is established between the first conduit and one of the formation and the wellbore and pressure equalization occurs therebetween;

and at least one gauge for measuring the pressure in the conduits.

56. The apparatus of claim 55 wherein when the protruding portion is in non-engagement with the sidewall of the wellbore such that fluid communication is established between the first conduit and the wellbore whereby at least one gauge reads annular pressure.

57. The apparatus of claim 56 wherein the non-protruding portion is in non-engagement with the sidewall of the wellbore such that fluid communication is established between the second conduit and the wellbore whereby at least one gauge measures annular pressure.

58. The apparatus of claim 55 wherein the protruding portion is in engagement with the sidewall of the wellbore such that fluid communication is established between the first conduit and the formation whereby at least one gauge measures pore pressure.

59. The apparatus of claim 58 wherein the non-protruding portion is in non-engagement with the sidewall of the wellbore such that fluid communication is established between the second conduit and the wellbore whereby at least one gauge measures annular pressure.

60. An apparatus for determining downhole pressures, the apparatus positionable in a downhole tool disposable in a wellbore, the apparatus comprising:

a drill collar having a cavity therein, the cavity adapted to receive downhole fluid, the downhole tool having an outer surface positionable in one of engagement and non-engagement with the wellbore wall, the conduit having an opening extending through the outer surface; and

a gauge operatively connected to the cavity for measuring pressure therein.

61. The apparatus of claim 60 wherein when the outer surface of the drill collar is in engagement with the wellbore wall, fluid communication is established between the conduit and the formation and pressure equalization occurs therebetween whereby the pore pressure is determined.

62. The apparatus of claim 60 wherein when the outer surface of the drill collar is in non-engagement with the wellbore wall, fluid communication is established between the conduit and the wellbore and pressure equalization occurs therebetween whereby the annular pressure is determined.