System for drilling deivated boreholes

• US 5,410,303 A
• Filed: 02/01/1994
• Issued: 04/25/1995
• Est. Priority Date: 05/15/1991
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Baroid Technology Incorporated
• Inventors: Comeau, Laurier E., Pustanyk, Randal H., Wallis, Nicholas P.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/190,719
• Time in Patent Office: 448 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 while drilling using a drill string having a drill bit at a lower end thereof, the drill bit being selectively powered by a downhole drilling motor within the drill string, the downhole drilling motor including a power assembly for rotating the drill bit, and a downhole drilling motor housing stationary with respect to the drill string above the power assembly of the drilling motor, the method comprising:

detecting a downhole parameter with a sensor located in the drill string below the power assembly of the drilling motor and stationary with respect to the downhole drilling motor housing;

transmitting a signal representative of the detected downhole parameter along the drill string from a lower downhole location in the drill string below the power assembly of the drilling motor to an upper downhole location in the drill string axially opposite the sensor with respect to the drilling motor;

receiving said signal at said upper downhole location in the drill string;

and

transmitting data indicative of said signal from said upper downhole location in said drill string to the surface.

2. A method according to claim 1, further comprising:

positioning the sensor in a cavity within an outer housing below the power assembly of the downhole motor.

3. A method according to claim 1, wherein the step of transmitting the signal comprises:

generating and transmitting an acoustic signal representative of the detected downhole parameter.

4. A method as defined in claim 3, further comprising:

position a rod within a cavity within an outer housing adjacent to its drill bit;

positioning a coil about the rod;

inputting a signal to the coil functionally related to the detected downhole parameter to deform the rod to produce the acoustic output signal.

5. A method according to claim 1, wherein the step of transmitting data comprises;

generating and transmitting mud pulse signals from said upper downhole location to the surface.

6. The method according to claim 1, wherein the step of transmitting the signal comprises:

encoding the signal representative of the detected downhole parameter; and

initiating the transmission of the signal along the drill string in response to a control signal.

7. The method of claim 1, wherein the step of transmitting a signal representative of the detected downhole parameter along the drill string further comprises:

transmitting the signal representative of the detected downhole parameter utilizing the metal housing of the drilling motor as a signal flow path for the transmitted signal.

8. Apparatus for signalling within a borehole while drilling using a drill string having a drill bit at a lower end thereof, the drill bit being selectively powered by a downhole drilling motor within the drill string, the downhole drilling motor including a power assembly for rotating the drill bit, and a downhole drilling motor housing stationary with respect to the drill string above the power assembly of the drilling motor, the apparatus comprising:

a sensor within the drill string at a stationary position with respect to the downhole drilling motor housing below the power assembly of the drilling motor to detect a downhole parameter and generate an output indicative of the detected downhole parameter;

a first downhole transmitter positioned within the drill string at a stationary position with respect to the downhole drilling motor housing below the power assembly of the drilling motor to receive the output from the sensor and transmit a signal along the drill string representative of the sensor output;

a downhole receiver positioned within the drill string axially opposite the sensor with respect to the drilling motor for receiving the signal transmitted by the first transmitter; and

a second downhole transmitter positioned within the drill string axially opposite the sensor with respect to the drilling motor for receiving the signal from the downhole receiver and for transmitting data indicative of the signal to the surface.

9. Apparatus according to claim 8, wherein the first downhole transmitter is an acoustic transmitter, and the second downhole transmitter is a mud pulse transmitter.

10. Apparatus according to claim 8, further comprising:

another sensor within the drill string positioned below the power assembly of the drilling motor for detecting another downhole parameter and generating the output indicative of the detected another downhole parameter; and

the second downhole transmitter transmits data to the surface indicative of the output from the another sensor.

11. Apparatus according to claim 10, wherein the first downhole transmitter comprises:

a magnetostrictive member;

magnetic field means for applying a magnetic field to said magnetostrictive member as a function of the sensor output to produce an acoustic signal representative of the sensor output.

12. Apparatus according to claim 11, further comprising:

the magnetostrictive member includes first and second pole pieces separated by an air gap; and

a compression member for axially comprising the first and second pole pieces.

13. Apparatus according to claim 8, further comprising:

a bend within the drill string below the power assembly of the drilling motor; and

the sensor is fixedly positioned within the drill string below the bend.

14. Apparatus according to claim 13, wherein:

the drilling motor includes a lower bearing assembly; and

the sensor is fixedly positioned within the drill string below the bearing assembly of the drilling motor.

15. A data sensing and transmission assembly for positioning within a lower end of a drill string during drilling and axially below a power section of a downhole motor selectively rotating a drill bit, the downhole drilling motor having a housing stationary with respect to a rotatable shaft for interconnecting the power section and the drill bit, the assembly comprising:

the drill motor housing having a sealed cavity therein;

a sensor within the sealed cavity for detecting a downhole parameter and generating an output indicative of the detected downhole parameter; and

a transmitter within the sealed cavity for receiving the output from the sensor indicative of the detected downhole parameter and for transmitting a signal along the drill string representative of the sensor output to a position axially above the power section of the downhole motor.

16. An assembly according to claim 15, wherein the transmitter comprises:

a magnetostrictive member; and

magnetic field means for applying a magnetic field to said magnetostrictive member in response to the sensor output to produce an acoustic signal representative of the sensor output.

17. The assembly according to claim 15, wherein the housing is a drilling motor bearing housing, and the sensor is rotationally fixed within the drilling motor bearing housing.

18. The assembly according to claim 15, further comprising:

providing a power supply within the sealed cavity for powering the transmitter.

19. The assembly according to claim 15, wherein the transmitter transmits acoustic signals having a frequency in the range of from 500 to 2,000 Hz.

20. The assembly according to claim 15, wherein the transmitter comprises:

a voltage to frequency converter within the sealed cavity for receiving voltage signals from the sensor and generating frequency signals in response thereto.

21. The assembly according to claim 15, further comprising:

a downhole computer within the sealed cavity for storing the transmitted signals.

22. The assembly according to claim 15, further comprising:

another sensor within the sealed cavity for detecting another downhole parameter; and

the transmitter transmits another signal indicative of the output from the another sensor.

23. The assembly according to claim 15, further comprising:

a bend in the drill string below the power section of the downhole motor;

and

the sensor and the transmitter are each positioned within the sealed cavity of the housing below the bend in the drill string.

24. The assembly according to claim 23, wherein:

the drilling motor includes a lower bearing assembly; and

the sensor is fixedly positioned within the drill string below the bearing assembly of the drilling motor.

25. A method of signalling within a borehole while drilling using a drill string having a drill bit at a lower end thereof, the drill bit being selectively powered by a downhole drilling motor within the drill string, the downhole drilling motor including a power assembly for rotating the drill bit, and a drilling motor housing stationary with respect to a drive shaft passing through the drilling motor housing and interconnecting the power assembly and the drill bit, the method comprising:

providing a plurality of sensors within a sealed cavity in a sensor housing below the power assembly of the downhole motor, the sensor housing being stationary with respect to the drilling motor housing;

detecting one or more downhole parameters with the plurality of sensors;

transmitting one or more signals representative of the detected one or more downhole parameters along the drill string from a lower downhole location in the drill string below the power assembly of the drilling motor to an upper downhole location in the drill string axially opposite the plurality of sensors with respect to the drilling motor;

receiving said one or more signals at said upper downhole location in the drill string;

and

transmitting data indicative of said one or more signals from sand upper downhole location in said drill string to the surface.

26. A method according to claim 25, further comprising:

storing said one or more signals downhole.

27. A method according to claim 25, wherein the step of transmitting data comprises:

generating and transmitting mud pulse signals from said upper downhole location to the surface.

28. The method according to claim 25, further comprising:

providing a bend in the drill string below the power assembly of the downhole drilling motor;

and

positioning the plurality of sensors in the sealed cavity below the bend.

29. A method of signalling within a borehole while drilling using a drill string having a drill bit at a lower end thereof, the drill bit being selectively powered by a downhole drilling motor within the drill string, the downhole drilling motor including a power assembly for rotating a drill bit, and a downhole drilling motor housing stationary with respect to the rotating drill bit, the method comprising:

detecting a downhole parameter with a sensor located in the drill string below the power section of the drilling motor and stationary with respect to the drilling motor housing;

transmitting a signal representative of the detected downhole parameters along the drill string from a lower downhole location in the drill string below the power assembly of the drilling motor to an upper downhole location in the drill string axially opposite the sensor with respect to the drilling motor;

receiving said signal at said upper downhole location in the drill string;

transmitting data indicative of said signal in real time from said upper downhole location in said drill string to the surface; and

altering drilling trajectory in response to the transmitted data.

30. A method as defined in claim 29, further comprising:

storing said signal downhole at a location above the power assembly of the drilling motor.

31. A method according to claim 29, wherein the step of transmitting data comprises:

generating and transmitting mud pulse signals from said upper downhole location to the surface.

32. The method according to claim 29, further comprising:

providing a bend in the drill string below the power assembly of the downhole drilling motor;

and

positioning the sensor in the drill string below the power assembly of the drilling motor.

33. The method according to claim 32, further comprising:

providing a lower bearing assembly within the downhole drilling motor;

and

positioning the sensor below the lower bearing assembly.

34. Apparatus for signalling within a borehole while drilling using a drill string having a drill bit at a lower end thereof, the drill string including a bent housing for effecting directional drilling, the drill bit being selectively powered by a downhole drilling motor within the drill string, the downhole drilling motor including a power assembly for rotating the drill bit, and a downhole drilling motor housing stationary with respect to the bent housing in the drill string, the apparatus comprising:

a sensor within the drill string at a stationary position with respect to the downhole drilling motor housing below the power assembly of the drilling motor to detect a downhole parameter and generate an output indicative of the detected downhole parameter;

a first downhole transmitter positioned within the drill string below the power assembly of the drilling motor to receive the output from the sensor and a transmit a signal along the drill string representative of the sensor output;

a downhole receiver positioned within the drill string axially opposite the sensor with respect to the drilling motor for receiving the signal transmitted by the first transmitter;

a second downhole transmitter positioned within the drill string axially opposite the sensor with respect to the drilling motor for receiving the signal from the downhole receiver and for transmitting data indicative of the signal to the surface; and

a downhole memory unit within the drill string for storing data indicative of the detected downhole parameter.

35. Apparatus according to claim 34, further comprising:

another sensor within the drill string positioned below the power assembly of the drilling motor for detecting another downhole parameter and generating an output indicative of the detected another downhole parameter; and

the second downhole transmitter transmits data to the surface indicative of the output from the another sensor.

36. Apparatus as defined to claim 35, further comprising:

one or more sealed cavities within an annular sensor housing below the power assembly of the downhole motor for receiving the sensor and the another sensor, said drill bit being rotatable with respect to said annular sensor housing.

37. Apparatus according to claim 34, further comprising:

a downhole power supply for powering said sensor.

38. Apparatus as defined in claim 37, wherein said power supply is driven in response to rotation of a drive shaft rotating the drill bit.

39. The apparatus according to claim 34, further comprising:

the bent housing in the drill string is below the power assembly of the downhole motor; and

the sensor and the first downhole transmitter are each positioned within the drill string below the bent housing.

40. A data sensing and transmission assembly for positioning within a lower end of a drill string during drilling and axially below a power section of a downhole motor selectively rotating a drill bit, the downhole motor including an outer motor housing stationary with respect to the rotating it, the assembly comprising:

a sensor housing below said power assembly of said downhole motor and stationary with respect to the drilling motor housing, the sensor housing having one or more sealed cavities therein;

a plurality of sensors within the one or more sealed sensor cavities for detecting one or more downhole parameters and generating an output indicative of the detected downhole parameters; and

a transmitter within one or more sealed cavities for receiving the output from the plurality of sensors indicative of the detected downhole parameters and for transmitting a signal along the drill string representative of the output to a position axially above the power section of the downhole motor.

41. The assembly as defined in claim 40, wherein said transmitter transmits mud signals to the surface.

42. The assembly as defined in claim 40, further comprising:

a bend in the drill string below the power section of the downhole motor; and

the sensor housing is positioned within the downhole motor below the bend.

43. Apparatus for signalling within a borehole along a drill string having a drill bit at a lower end thereof and bet housing in the drill string for effecting directional drilling, the drill bit being selectively powered by a downhole drilling motor within the drill string, the downhole motor including a power assembly for rotating the drill bit, and a downhole motor housing stationary with respect to the bent housing in the drill string, the apparatus comprising:

one or more sensor positioned within the drill string below the power assembly of the drilling motor at a stationary position with respect to the downhole motor housing to detect one or more downhole parameters and generate one or more outputs indicative of the one or more detected downhole parameters;

a downhole transmitter positioned within the downhole motor housing below the power assembly of the drilling motor for transmitting signals representative of the one or more sensor outputs;

a signal connection between the downhole transmitter and each of the one or more sensors to allow the downhole transmitter to receive the one or more sensor outputs; and

a receiver positioned uphole with respect to the power assembly of the downhole drilling motor for receiving the signals from the downhole transmitter.

44. The apparatus of claim 43, wherein each of the one or more sensors is fixably mounted within the downhole motor housing.

45. The apparatus of claim 43, wherein the downhole transmitter is positioned within a bearing housing portion of the downhole motor housing.

46. Apparatus for signalling within a borehole along a drill string having a drill bit at a lower end thereof, the drill bit being selectively powered by a downhole drilling motor within the drill string,the downhole drilling motor including a power assembly for rotating the drill bit, a rotary shaft interconnecting the power assembly and the drill bit, and a drilling motor housing stationary with respect to the rotary shaft, the apparatus comprising:

a bent housing stationary with respect to the drilling motor housing and stationary with respect to the rotating drill bit;

a bearing housing fixably positioned with respect to the bent housing a stationary with respect to the rotating drill bit;

a mandrel powered by the power assembly and rotatable within the bearing housing;

a sensor housing disposed downhole below the power assembly of the drilling motor, the sensor housing being stationary with respect to drilling motor housing;

a sensor fixably secured within the sensor housing to detect a downhole parameter and generate an output indicative of the detected downhole parameter; and

a downhole transmitter secured within the sensor housing for receiving the output of the sensor and transmitting a signal representative of the detected downhole parameter.

47. The apparatus of claim 46, wherein the sensor housing and the bearing housing are an integral housing.

48. The apparatus of claim 46, wherein the sensor housing and the bent housing are an integral housing.