Steerable drilling system and method

• US 20030010534A1
• Filed: 08/29/2002
• Published: 01/16/2003
• Est. Priority Date: 12/21/1998
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Gleltman, Daniel D., Rao, M. Vikram, Walker, Colin, Boulton, Roger, Hardin, John R. Jr., Gaynor, Thomas M., Chen, Chen-Kang D.
• Granted Patent: US 7,147,066 B2
• Time in Patent Office: Days
• US Class Current: 175/61
• CPC Class Codes: E21B 47/013 Devices specially adapted for supporting measuring instruments on drill bits
• CPC Class Codes: E21B 7/067 with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub
• CPC Class Codes: E21B 7/068 drilled by a down-hole drilling motor down-hole drives per se E21B4/00, E21B7/067 takes precedence

Abstract

A bottom hole assembly 10 for drilling a deviated borehole includes a positive displacement motor (PDM) 12 or a rotary steerable device (RSD) 110 having a substantially uniform diameter motor housing outer surface without stabilizers extending radially therefrom. In a PDM application, the motor housing 14 may have a fixed bend therein between an upper power section 16 and a lower bearing section 18. The long gauge bit 20 powered by the motor 10 may have a bit face 22 with cutters 28 thereon and a gauge section 24 having a uniform diameter cylindrical surface 26. The gauge section 24 preferably has an axial length at least 75% of the bit diameter. The axial spacing between the bit face and the bend of the motor housing preferably is less than twelve times the bit diameter. According to the method of the present invention, the bit may be rotated at a speed of less than 350 rpm by the PDM and/or rotation of the RSD from the surface.

Claims

1. A bottom hole assembly for drilling a deviated borehole, the bottom hole assembly comprising:

a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend;

a housing having a substantially uniform diameter housing outer surface, the housing containing at least a portion of the upper axis of the rotary shaft;

a bit powered by the rotating shaft, the bit having a bit face defining a bit diameter;

a gauge section having a substantially uniform diameter cylindrical surface spaced above the bit face; and

the bit and gauge section together having a total gauge length of at least 75% of the bit diameter and a portion of the total gauge length which is substantially gauge is at least 50% of the total gauge length.

2. The bottom hole assembly as defined in claim 1, wherein an axial spacing between the bend and the bit face is less than twelve times the bit diameter.

3. The bottom hole assembly as defined in claim 2, wherein the bit is a long gauge bit supporting the gauge section.

4. The bottom hole assembly as defined in claim 2, wherein the bit is a conventional bit with a piggyback stabilizer providing at least a portion of the gauge section.

5. The bottom hole assembly as defined in claim 2, further comprising:

the rotary shaft having a pin connection as its lowermost end; and

the bit having a box connection at its upper end for mating interconnection with the pin connection to reduce an axial spacing between the bend and the bit.

6. The bottom hole assembly as defined in claim 1, wherein the housing comprises a rotary steerable housing.

7. The bottom hole assembly as defined in claim 6, wherein an axial spacing between the bend and the bit face is less than eight times the bit diameter.

8. The bottom hole assembly as defined in claim 6, wherein the bend is less than about 0.6°

.

9. The bottom hole assembly as defined in claim 6, wherein the rotary shaft is rotated from the surface.

10. The bottom hole assembly as defined in claim 6, wherein the rotary steerable housing is suspended in the wellbore from coiled tubing.

11. The bottom hole assembly defined in claim 1, wherein the housing comprises a motor housing.

12. The bottom hole assembly as defined in claim 11, wherein the bottom hole assembly is supported in the wellbore by drill pipe, such that the motor housing is rotated with the drill pipe to form a straight section of the deviated borehole.

13. The bottom hole assembly as defined in claim 12, further comprising:

a drill collar assembly above the motor housing, the drill collar assembly having an axial length less than 200 feet.

14. The bottom hole assembly as defined in claim 11, wherein the motor housing is suspended in the well from coiled tubing.

15. The bottom hole assembly defined in claim 11, wherein the axial spacing between the bit face and the bend of the motor housing is less than ten times the bit diameter.

16. The bottom hole assembly as defined in claim 11, wherein a bend in the motor housing is less than about 1.5°

.

17. The bottom hole assembly as defined in claim 1, wherein the bit has a total gauge length of at least 90% of the bit diameter.

18. The bottom hole assembly as defined in claim 1, further comprising:

one or more downhole sensors contained within the bottom hole assembly for sensing one or more desired borehole parameters.

19. The bottom hole assembly as defined in claim 1, further comprising:

one or more downhole sensors positioned substantially along the total gauge length for sensing one or more desired borehole parameters.

20. The bottom hole assembly as defined in claim 19, wherein the one or more downhole sensors are supported on a long gauge bit.

21. The bottom hole assembly as defined in claim 19, wherein the one or more sensors are supported on a piggyback stabilizer.

24. The method as defined in claim 23, further comprising:

axially spacing the bend from the bit face less than twelve times the bit diameter.

25. The method as defined in claim 23, wherein the bend is less than about 1.5°

.

26. The method as defined in claim 23, wherein the bend is less than about 0.60.

27. The method as defined in claim 23, further comprising:

the housing is a motor housing; and

(d) rotating the motor housing within the borehole to rotate the bit to form a straight section of the deviated borehole.

28. The method as defined in claim 27, wherein steps (c) and (d) are each repeated one or more times, and step (d) is performed between two step (c) operations.

29. The method as defined in claim 23, wherein the gauge section is supported on a long gauge bit.

30. The method as defined in claim 23, wherein at least a portion of the gauge section is supported on a piggyback stabilizer.

31. The method as defined in claim 23, further comprising:

positioning one or more downhole sensors substantially along the total gauge length to sense a desired downhole parameter.

32. The method as defined in claim 23, further comprising:

suspending the housing in the wellbore from coiled tubing.

33. The method as defined in claim 23, further comprising:

positioning one or more downhole sensors provided substantially along the total gauge length for sensing one or more desired borehole parameters.

34. The method as defined in claim 33, wherein the one or more downhole sensors are positioned substantially along the gauge section of a long gauge bit.

35. The method as defined in claim 33, wherein the one or more downhole sensors are positioned substantially along the gauge section of a piggyback stabilizer.

38. The bottom hole assembly as defined in claim 37, wherein an axial spacing along the lower central axis between the bend and the bit face being less than twelve times the bit diameter.

39. The bottom hole assembly as defined in claim 37, further comprising:

the shaft having a pin connection at its lowermost end; and

the bit having a box connection at its upper end for mating interconnection with the pin connection to reduce an axial spacing between the bend and the bit face.

40. The bottom hole assembly as defined in claim 37, wherein the axial spacing between the bend and the bit face is less than eight times the bit diameter.

41. The bottom hole assembly as defined in claim 40, wherein the bend is less than about 0.6°

.

42. The bottom hole assembly as defined in claim 37, wherein the axial spacing between the bend and the bit face is less than ten times the bit diameter.

43. The bottom hole assembly as defined in claim 42, wherein the bend is less than about 1.5°

.

44. The bottom hole assembly as defined in claim 37, wherein the bit has a total gauge length of at least 90% of the bit diameter.

45. The bottom hole assembly as defined in claim 37, wherein the rotary shaft is rotated from the surface.

46. The bottom hole assembly as defined in claim 37, wherein the bit is a long gauge bit supporting the gauge section.

47. The bottom hole assembly as defined in claim 37, wherein the bit is a conventional bit and a piggyback stabilizer supporting at least a portion of the gauge section.

48. The bottom hole assembly as defined in claim 37, further comprising:

one or more downhole sensors within the bottom hole assembly for sensing a desired borehole parameter.

49. The bottom hole assembly as defined in claim 37, further comprising:

one or more downhole sensors positioned substantially along the gauge section of the bit for sensing a desired borehole parameter.

36. The method as defined in claim 23, further comprising:

controlling weight on the bit such that the bit face exerts less than about 200 pounds axial force per square inch of bit face cross-sectional area.

37. A bottom hole assembly for drilling a deviated borehole, the bottom hole assembly comprising:

a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend;

a housing having a substantially uniform diameter motor housing outer surface, the housing containing at least a portion of the upper axis of the rotary shaft;

a bit powered by the rotating shaft, the bit having a bit face defining a bit diameter;

a gauge section having a substantially uniform diameter cylindrical surface spaced above the bit face; and

the bit having a centerline which has a maximum eccentricity relative to a centerline of the rotary shaft extending between the housing and the bit of no greater than about 0.03 inches.

50. A method of drilling a deviated borehole utilizing a bottom hole assembly including a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend, the bottom hole assembly further including a bit rotated by the rotary shaft and having a bit face defining a bit diameter, the method comprising:

(a) providing a housing having a substantially uniform diameter outer surface surrounding the rotary shaft upper axis;

(b) providing a gauge section on the bit, the gauge section having a substantially uniform diameter substantially cylindrical surface spaced above a bit face, the uniform_diameter substantially cylindrical surface having a bit centerline which has a maximum eccentricity relative to a centerline of the rotary shaft extending between the housing and the bit of less than 0.03 inches; and

(c) rotating the bit at a speed of less than 350 rpm to form a curved section of the deviated borehole.

51. The method as defined in claim 50, further comprising:

axially spacing the bend from the bit face less than twelve times the bit diameter.

52. The method as defined in claim 50, wherein the bend is less than about 1.5°

.

53. The method as defined in claim 50, wherein the bend is less than about 0.6°

.

54. The method as defined in claim 50, further comprising:

(d) rotating a housing within the borehole to rotate the bit to form a straight section of the deviated borehole.

55. The method as defined in claim 50, further comprising:

positioning one or more downhole sensors within the bottom hole assembly to sense a desired downhole parameter.

56. The method as defined in claim 50, further comprising:

one or more downhole sensors positioned substantially along the total gauge length for sensing one or more desired borehole parameters.

58. The bottom hole assembly as defined in claim 57, wherein an axial spacing between the bend and the bit face is less than twelve times the bit diameter.

59. The bottom hole assembly as defined in claim 57, wherein the one or more sensors include a vibration sensor.

60. The bottom hole assembly as defined in claim 57, wherein the one or more sensors include an RPM sensor for sensing the rotational speed of the rotary shaft.

61. The bottom hole assembly as defined in claim 57, further comprising:

the rotary shaft being rotated by a downhole motor;

an MWD sub located above the motor; and

a telemetry system for communicating data from the one or more sensors in real time to the MWD sub, the telemetry system being selected from an acoustic system and an electromagnetic system.

62. The bottom hole assembly as defined in claim 57, further comprising;

a data storage unit supported on the long gauge bit for storing data from the one or more sensors.

63. The bottom hole assembly as defined in claim 57, wherein the one or more sensors sense indications which affect drilling and are provided to the drilling operator in real time.

57. A bottom hole assembly for drilling a deviated borehole, the bottom hole assembly comprising:

a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend;

a housing having a substantially uniform diameter housing outer surface, the housing containing at least a portion of the upper axis of the rotary shaft;

a long gauge bit powered by the rotating shaft, the long gauge bit having a bit face defining a bit diameter and a gauge section having a substantially uniform diameter cylindrical surface, the bit having a total gauge length of at least 75% of the bit diameter; and

a portion of the total gauge length which is substantially gauge is at least 50% of the total gauge length; and

one or more sensors spaced substantially along the gauge section of the long gauge bit for sensing selected parameters while drilling.

64. A bottom hole assembly for drilling a deviated borehole, the bottom hole assembly comprising:

a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend;

a housing having a substantially uniform diameter housing outer surface, the housing containing at least a portion of the upper axis of the rotary shaft;

a bit powered by the rotating shaft, the bit having a bit face defining a bit diameter;

a piggyback stabilizer positioned above the bit and having a stabilizer gauge section;

the stabilizer gauge section having a substantially uniform diameter cylindrical surface spaced above the bit face, the bit and stabilizer gauge section together having a total gauge length of at least 75% of the bit diameter and a portion of the total gauge length which is substantially gauge is at least 50% of the total gauge length; and

one or more sensors spaced substantially along the stabilizer gauge section for sensing selected parameters while drilling.

65. The bottom hole assembly as defined in claim 64, wherein an axial spacing between the bend and the bit face is less than twelve times the bit diameter.

66. The bottom hole assembly as defined in claim 65, wherein the one or more sensors include a vibration sensor.

67. The bottom hole assembly as defined in claim 65, wherein the one or more sensors include an RPM sensor for sensing the rotational speed of the rotary shaft.

68. The bottom hole assembly as defined in claim 65, further comprising:

the rotary shaft being rotated by a downhole motor;

an MWD sub located above the motor; and

a telemetry system for communicating data from the one or more sensors in real time to the MWD sub, the telemetry system being selected from an acoustic system and an electromagnetic system.

69. The bottom hole assembly as defined in claim 65, further comprising;

a data storage unit supported substantially along the total gauge length of the bit and gauge section for storing data from the one or more sensors.

70. The bottom hole assembly as defined in claim 65, wherein the one or more sensors sense indications which affect drilling and are provided to the drilling operator in real time.

71. A bottom hole assembly for drilling a deviated borehole, the bottom hole assembly comprising:

a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend;

a housing having a substantially uniform diameter housing outer surface, the housing containing at least a portion of the upper axis of the rotary shaft;

a bit powered by the rotating shaft, the bit having a bit face defining a bit diameter and a gauge section having a substantially uniform diameter cylindrical surface; and

one or more sensors spaced substantially along the gauge section of the bit for sensing selected parameters while drilling.

72. The bottom hole assembly as defined in claim 71, wherein the one or more sensors include a vibration sensor.

73. The bottom hole assembly as defined in claim 71, wherein the one or more sensors include an RPM sensor for sensing the rotational speed of the rotary shaft.

74. The bottom hole assembly as defined in claim 71, further comprising:

the rotary shaft being rotated by a downhole motor;

an MWD sub located above the motor; and

a telemetry system for communicating data from the one or more sensors in real time to the MWD sub, the telemetry system being selected from an acoustic system and an electromagnetic system.

75. The bottom hole assembly as defined in claim 71, further comprising;

a data storage unit supported along the total gauge length of the bit and gauge section for storing data from the one or more sensors.

76. The bottom hole assembly as defined in claim 71, wherein the one or more sensors sense indications which affect drilling and are provided to the drilling operator in real time.

77. A method of drilling a deviated borehole utilizing a bottom hole assembly including a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend, the bottom hole assembly further including a bit rotated by the rotary shaft and having a bit face defining a bit diameter, the method comprising:

(a) providing a housing having a substantially uniform diameter outer surface surrounding the rotary shaft upper axis;

(b) providing a gauge section, the bit and gauge section together having a total gauge length with a uniform diameter cylindrical surface thereon; and

(c) providing one or more sensors spaced substantially along the total gauge length for sensing selected parameters while drilling.

78. The method as defined in claim 77, further comprising:

(d) rotating the bit at a speed of less than 350 rpm to form a curved section of the deviated borehole.

79. The method as defined in claim 77, wherein the one or more sensors sense at least one of vibration and shaft RPM.

80. The method as defined in claim 77, further comprising:

rotating the rotary shaft by a downhole motor;

positioning a MWD sub above the motor; and

transmitting data from the sensors to the MWD sub in real time.

81. The method as defined in claim 77, further comprising;

storing data from the sensors in a memory unit spaced along the total gauge length.

82. The method as defined in claim 77, wherein the one or more sensors are positioned substantially along the gauge section of a long gauge bit.

83. The method as defined in claim 77, wherein the one or more sensors are supported substantially along the gauge section of a piggyback stabilizer.

88. The bottom hole assembly as defined in claim 87, further comprising:

the rotary shaft having a pin connection at its lowermost end; and

the bit having a box connection at its upper end for mating interconnection with the pin connection to reduce an axial spacing between the bend and the bit face.

89. The bottom hole assembly as defined in claim 87, wherein the bit is a long gauge bit supporting the gauge section.

90. The bottom hole assembly as defined in claim 87, wherein the bit includes a piggyback stabilizer supports at least a portion of the total gauge length.

91. The bottom hole assembly as defined in claim 87, wherein the axial spacing between the bend and the bit face is less than eight times the bit diameter and the bend is less than about 0.6°

.

92. The bottom hole assembly as defined in claim 87, wherein the total gauge length is at least 90% of the bit diameter.

93. The bottom hole assembly as defined in claim 87, further comprising:

one or more downhole sensors positioned substantially along the gauge section of the long gauge bit for sensing a desired borehole parameter.

94. The bottom hole assembly as defined in claim 87, further comprising:

one or more downhole sensors housed substantially within the gauge section of the long gauge bit for sensing a desired borehole parameter.

95. The bottom hole assembly as defined in claim 87, wherein an axial spacing between the bend and the bit face being less than ten times the bit diameter.

96. A method of drilling a deviated borehole utilizing a bottom hole assembly including a rotatable shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend, the bottom hole assembly further including a bit rotated by the rotary shaft and having a bit face defining a bit diameter, the method comprising:

(a) rotating from the surface to rotate a downhole shaft;

(b) providing a housing having a substantially uniform diameter outer surface containing the rotary shaft upper axis;

(c) providing a gauge section on the bit, the gauge section having a substantially uniform diameter cylindrical surface spaced above the bit face, the bit and gauge section together having a total gauge length of at least 75% of the bit diameter and a portion of the total gauge length which is substantially gauge is at least 50% of the total gauge length; and

(d) rotating the bit at a speed of less than 350 rpm to form a curved section of the deviated borehole.

97. The method as defined in claim 96, further comprising:

axially spacing the bend from the bit face less than twelve times the bit diameter.

98. The method as defined in claim 96, wherein the bend is less than about 0.6°

.

99. The method as defined in claim 96, further comprising:

positioning one or more downhole sensors substantially along the gauge section of the bit to sense a desired downhole parameter.

100. The method as defined in claim 96, further comprising:

positioning one or more downhole sensors along the bottom hole assembly to sense a desired downhole parameter.