System for drilling deviated boreholes

• US 5,602,541 A
• Filed: 04/24/1995
• Issued: 02/11/1997
• Est. Priority Date: 05/15/1991
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Baroid Technology Incorporated (Halliburton Company)
• Inventors: Comeau, Laurier E., Pustanyk, Randal H., Wallis, Nicholas P.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/427,602
• Time in Patent Office: 659 Days
• Field of Search: 367/25, 367/81, 367/82, 367/83, 340/853.2, 340/853.3, 340/853.4, 340/853.5, 340/853.6, 340/854.3, 340/854.4, 340/854.5, 340/854.6, 340/854.8, 340/856.1, 175/40, 175/45, 175/61
• US Class Current: 340/853.3
• CPC Class Codes: E21B 47/01 Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: E21B 47/16 through the drill string or casing , e.g. by torsional acoustic waves
• CPC Class Codes: E21B 47/18 through the well fluid , e.g. mud pressure pulse telemetry
• CPC Class Codes: E21B 47/26 Storing data down-hole, e.g. in a memory or on a record carrier
• CPC Class Codes: E21B 7/04 Directional drilling
• 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

Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations. A sensor permanently positioned in the drilling string between the drill bit and the drill motor detects a downhole parameter. An MWD tool may be provided within a non-magnetic portion of the drill string for receiving and transmitting a sensor representative signal to the surface. The sensor signal allows the drilling operation to be altered, and highly reliable and near-bit information thus improves the drilling operation.

Claims

1. A method of signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, a downhole drilling motor being positioned within said drill string, said downhole drilling motor having a power assembly operable for rotating said drill bit, said method comprising:

rotating said drill bit with said downhole drilling motor at a bit rotation speed in revolutions per minute with respect to said borehole;

supporting at least one sensor at a location below said power assembly of said downhole drilling motor such that said at least one sensor does not rotate at said bit rotation speed; and

detecting a downhole parameter with said at least one sensor.

2. The method of claim 1, further comprising:

relaying a signal representative of said detected downhole parameter from a position below said power assembly of said downhole drilling motor to a position above said power assembly of said downhole drilling motor.

3. The method of claim 1, wherein said step of supporting said at least one sensor further comprises:

supporting said at least one sensor such that said at least one sensor moves axially substantially in concert with said drill bit.

4. The method of claim 1, further comprising:

relaying a signal representative of said detected downhole parameter from a lower downhole position above said power assembly of said downhole drilling motor to a surface location.

5. The method of claim 1, further comprising:

supporting a first downhole transmitter at a location below said power assembly of said downhole drilling motor.

6. The method of claim 5, wherein said step of supporting said first downhole transmitter further comprises:

supporting said first downhole transmitter such that said first downhole transmitter does not rotate at said bit rotation speed.

7. The method of claim 5, further comprising:

transmitting said signal representative of said detected downhole parameter from said first transmitter to a second transmitter at a position above said power assembly of said downhole drilling motor.

8. The method of claim 1, wherein said step of supporting further comprises:

affixing said at least one sensor to a housing of said downhole drilling motor.

9. Apparatus for signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, said drill bit being powered by a downhole drilling motor within said drill string, said downhole motor including a power assembly for rotating said drill bit, said apparatus comprising:

one or more sensors mounted below said power assembly of said downhole motor such that said one or more sensors are rotationally uncoupled with respect to said drill bit so as to be rotationally independent of said drill bit;

a first downhole signal transmitter positioned below said power assembly of said downhole motor for relaying signals representative of one or more parameters detected by said one or more sensors;

a second downhole signal transmitter positioned above said power assembly of said downhole motor for relaying said signals representative of said one or more parameters detected by said one or more sensors to a surface location; and

at least one receiver positioned at said surface location for receiving said signals representative of said one or more parameters detected by said one or more sensors.

10. The apparatus of claim 9, further comprising:

a shaft rotatably secured to said bit for rotating said bit;

said one or more sensors being mounted so as to be axially moveable substantially in concert with said shaft and said bit.

11. The apparatus of claim 9, further comprising:

a housing annularly disposed with respect to said shaft, said one or more sensors being affixed to said housing.

12. The apparatus of claim 11, wherein:

said first downhole signal transmitter is affixed to said housing.

13. A method of signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, said drill bit being powered by a downhole drilling motor within said drill string, said downhole drilling motor including a power assembly, said method comprising:

rotating said drill bit with said downhole drilling motor at a bit rotation speed in revolutions per minute with respect to said borehole;

supporting at least one signal transmitter at a location below said power assembly of said downhole drilling motor such that said at least one signal transmitter does not rotate at said bit rotation speed;

detecting a downhole parameter with at least one sensor; and

transmitting a signal representative of said detected downhole parameter with said at least one signal transmitter.

14. The method of claim 13, wherein said step of supporting said at least one signal transmitter further comprises:

supporting said at least one signal transmitter such that said at least one signal transmitter moves axially substantially in concert with said drill bit.

15. The method of claim 13, further comprising:

relaying said signal representative of said detected downhole parameter from a lower downhole position above said power assembly of said downhole drilling motor to a surface location.

16. The method of claim 13, wherein said step of transmitting further comprises:

transmitting from a position below said power assembly of said downhole drilling motor to a position above said power assembly of said downhole drilling motor.

17. The method of claim 13, wherein said step of supporting further comprises:

supporting said at least one sensor such that it does not rotate at said bit rotation speed.

18. The method of claim 13, further comprising:

transmitting said signal representative of said detected downhole parameter from said at least one signal transmitter to a second signal transmitter at a position above said power assembly of said downhole drilling motor.

19. The method of claim 13, wherein said step of supporting further comprises:

affixing said at least one signal transmitter to a housing of said downhole drilling motor.

20. Apparatus for signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, said drill bit being powered by a downhole drilling motor within said drill string, said downhole motor including a power assembly for rotating said drill bit, said apparatus comprising:

one or more sensors positioned below said power assembly of said downhole motor for detecting one or more parameters;

a first downhole transmitter mounted below said power assembly of said downhole motor such that said first downhole transmitter is rotationally uncoupled with respect to said drill bit so as to be rotationally independent of said drill bit, said first downhole transmitter relaying a signal representative of said one or more parameters detected by said one or more sensors; and

at least one receiver positioned at a surface location for receiving said signal representative of said one or more parameters detected by said one or more sensors.

21. The apparatus of claim 20, further comprising:

a shaft portion of said drill string rotatably secured to said bit for rotating said bit; and

said first downhole transmitter being axially coupled with respect to said shaft portion so as to be substantially axially moveable with said shaft portion and said bit.

22. The apparatus of claim 21, further comprising:

an annular housing in surrounding relationship to said shaft portion, said first downhole transmitter being affixed to said annular housing.

23. The apparatus of claim 22, wherein:

said one or more sensors are affixed to said annular housing.

24. Apparatus for signalling within a borehole having therein a drill string, said drill bit being powered by a downhole drilling motor within said drill string, at least a portion of said drill string forming a drive shaft rotatable by said downhole drilling motor, said drive shaft being secured to a drill bit at one end thereof and being rotatable by said downhole drilling motor adjacent a second end thereof to thereby rotate said drill bit in response to rotation of said drive shaft, said apparatus comprising:

a sensor support member mounted at a location below said second end of said drive shaft and being rotatably recoupled with respect to said drive shaft such that said sensor support member is rotatably independent of said drive shaft;

one or more sensors carried by said sensor support member for detecting one or more downhole parameters; and

a signal transmission system for relaying signals representative of said one or more downhole parameters to a location in said drill string uphole with respect to said drive shaft.

25. The apparatus of claim 24, wherein:

said sensor support member is mounted radially outwardly with respect to said drive shaft.

26. The apparatus of claim 24, further comprising:

a motor housing in surrounding relationship to said drive shaft, said sensor support member being rotatably secured with respect to said motor housing.

27. The apparatus of claim 24, further comprising:

a signal transmitter mounted at a position below said second end of said drive shaft for transmission of a signal representative of said one or more downhole parameters.

28. The apparatus of claim 24, further comprising:

a motor housing in surrounding relationship to said drive shaft, said signal transmitter being rotatably secured with respect to said motor housing.

29. A method of signalling within a borehole having a drill string therein, at least a portion of said drill string forming a drive shaft with said drive shaft being rotatable by a drive unit, said drive shaft being attached to a drill bit at a first end of said drive shaft and being driven by said drive unit adjacent a second end thereof, said drill bit rotating in response to rotation of said drive shaft, said method comprising said following steps:

rotating said drive shaft with said drive unit to thereby rotate said drill bit at a drill bit rotation speed in revolutions per minute with respect to said borehole;

supporting at least one sensor at a location below said second end of said drive shaft such that said at least one sensor does not rotate at said drill bit rotation speed;

supporting a downhole signal transmitter at a location below said second end of said drive shaft; and

sensing at least one parameter with said at least one sensor.

30. The method of claim 29, further comprising:

transmitting a signal representative of said at least one parameter with said downhole signal transmitter.

31. The method of claim 29, further comprising:

relaying a signal representative of said at least one parameter from a position below said top end of said drive shaft to a surface position.

32. The method of claim 29, wherein said step of rotating further comprises:

pumping fluid through said drill string to activate said drive unit for rotation of said drive shaft.