Apparatus and method for downhole dynamics measurements

• US 20070289373A1
• Filed: 06/15/2006
• Published: 12/20/2007
• Est. Priority Date: 06/15/2006
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: PathFinder Energy Services Inc (Schlumberger NV)
• Inventors: Sugiura, Junichi
• Granted Patent: US 7,571,643 B2
• Time in Patent Office: Days
• US Class Current: 73/152.460
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 45/00 Measuring the drilling time or rate of penetration
• CPC Class Codes: E21B 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: E21B 47/12 Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
• CPC Class Codes: E21B 7/062 the tool shaft rotating inside a non-rotating guide travelling with the shaft E21B7/067 and E21B7/068 take precedence

Abstract

Aspects of this invention include a rotary steerable steering tool having a sensor arrangement for measuring downhole dynamic conditions. Rotary steerable tools in accordance with this invention include a rotation rate measurement device disposed to measure a difference in rotation rates between a drive shaft and an outer, substantially non-rotating housing. A controller is configured to determine a stick/slip parameter from the rotation rate measurements. Exemplary embodiments may also optionally include a tri-axial accelerometer arrangement deployed in the housing for measuring lateral vibrations and bit bounce. Downhole measurement of stick/slip and other vibration components during drilling advantageously enables corrective measures to be implemented when dangerous dynamic conditions are encountered.

Claims

1. A rotary steerable tool configured to operate in a borehole, the rotary steerable tool comprising:

a shaft;

a housing deployed about the shaft, the shaft disposed to rotate substantially freely in the housing;

a rotation rate measurement device disposed to measure a rotation rate of the shaft relative to the housing, the rotation rate measurement device including at least one sensor and at least one marker, the sensor disposed to send an electrical pulse to a controller each time one of the markers and the sensor rotate past one another; and

the controller configured to calculate a stick/slip parameter from said electric pulses.

2. The rotary steerable tool of claim 1, wherein the controller is configured to calculate the stick/slip parameter according to an equation selected from the group consisting of:

3. The rotary steerable tool of claim 1, wherein the controller is further configured to calculate instantaneous and average rotation rates of the shaft relative to the housing from said electrical pulses.

4. The rotary steerable tool of claim 1, wherein the controller is further configured to calculate the rotation rate of the shaft according to at least one equation from the group consisting of:

5. The rotary steerable tool of claim 1, wherein the rotation rate measurement device comprises a Hall-effect sensor deployed in the housing and a plurality of magnetic markers deployed on the shaft.

6. The rotary steerable tool of claim 1, further comprising:

a tri-axial arrangement of accelerometers deployed in the housing, one of the accelerometers substantially aligned with a longitudinal axis of the rotary steerable tool, the accelerometers disposed to measure tri-axial acceleration components of the housing.

7. The rotary steerable tool of claim 6, wherein the controller is further configured to determine a bit bounce parameter and a lateral vibration parameter from said measured tri-axial acceleration components.

8. The rotary steerable tool of claim 7, wherein the controller is further configured to determine borehole inclination and gravity tool face from said measured tri-axial acceleration components.

9. The rotary steerable tool of claim 7, wherein the controller is further configured to determine (i) the bit bounce parameter from a difference between instantaneous and average axial acceleration components and (ii) the lateral vibration parameter from a difference between instantaneous and average cross axial acceleration components.

10. A rotary steerable tool configured to operate in a borehole, the rotary steerable tool comprising:

a shaft;

a housing deployed about the shaft, the shaft disposed to rotate substantially freely in the housing;

a rotation rate measurement device disposed to measure a rotation rate of the shaft relative to the housing, the rotation rate measurement device including at least one sensor and a plurality of markers, the sensor disposed to send an electrical pulse to a controller each time one of the markers and the sensor rotate past one another;

a tri-axial accelerometer set deployed in the housing, the accelerometer set disposed to measure acceleration of the housing; and

the controller configured to determine (i) instantaneous and average rotation rates of the shaft from said electrical pulses, (ii) a stick/slip parameter from said instantaneous rotation rates, (iii) instantaneous and average tri-axial acceleration components from said accelerometer measurements, (iv) borehole inclination and gravity tool face from the average tri-axial acceleration components, and (v) bit bounce and lateral vibration parameters from the instantaneous tri-axial acceleration components.

11. The rotary steerable tool of claim 10, wherein the rotation rate measurement device comprises a Hall-effect sensor deployed in the housing and a plurality of magnetic markers deployed on the shaft.

12. The rotary steerable tool of claim 10, further comprising:

downhole memory suitable for storing the following parameters at predetermined time intervals during drilling;

(i) the instantaneous and average rotation rates of the shaft, (ii) the stick/slip parameter, (iii) the instantaneous and average tri-axial acceleration components, (iv) borehole inclination and gravity tool face, and (v) the bit bounce and lateral vibration parameters.

13. The rotary steerable tool of claim 10, wherein the controller is in electronic communication with a telemetry device configured to telemeter selected ones of the stick/slip parameter, the bit bounce parameter, and the lateral vibration parameter to a surface location.

14. The rotary steerable tool of claim 10, wherein:

the controller is configured to calculate the stick/slip parameter according to at least one equation selected from the group consisting of;

15. The rotary steerable tool of claim 10, wherein:

the controller is configured to calculate the bit bounce and lateral vibration parameters according to at least one equation selected from the group consisting of;

16. A method for determining a stick/slip parameter downhole during drilling of subterranean borehole, the method comprising:

(a) rotating a string of tools in a borehole, the string of tools including a rotary steerable tool and a drill bit rotationally coupled with a drill string, the rotary steerable tool including a shaft disposed to rotate substantially freely in a housing, the rotary steerable tool further including a rotation rate measurement device disposed to measure a rotation rate of the shaft relative to the housing, the rotation rate measurement device having at least one sensor and a plurality of markers, the sensor disposed to send an electrical pulse to a controller each time one of the markers and the sensor rotate past one another; and

(b) processing said electrical pulses to determine the stick/slip parameter.

17. The method of claim 16, wherein (b) further comprises:

(i) processing the electrical pulses to determine a plurality of instantaneous rotation rates of the shaft; and

(ii) processing the plurality of instantaneous rotation rates to determine the stick/slip parameter.

18. The method of claim 16, wherein (b) further comprises:

(i) processing the electrical pulses to determine a plurality of instantaneous rotation rates of the shaft and an average rotation rate of the shaft; and

(ii) processing the plurality of instantaneous rotation rates and the average rotation rate to determine the stick/slip parameter.

19. The method of claim 16, wherein (b) further comprises:

(i) counting a number of electrical pulses in each of a plurality of time intervals;

(ii) determining a maximum number of electrical pulses in the plurality of time intervals; and

(iii) processing the maximum number of electrical pulses to determine the stick/slip parameter.

20. The method of claim 19, wherein:

(ii) further comprises determining a minimum number of electrical pulses in the plurality of time intervals and an average number of electrical pulses in the plurality of time intervals; and

(iii) further comprises processing the maximum number, the minimum number, and to the average number of electrical pulses to determine the stick/slip parameter.

21. The method of claim 16, further comprising:

(c) telemetering said stick/slip parameter to a surface location.

22. The method of claim 16, wherein the stick/slip parameter is determined in (b) according to at least one equation of the group consisting of:

23. The method of claim 16, wherein:

the rotary steerable tool further includes a tri-axial arrangement of accelerometers deployed in the housing, one of the accelerometers substantially aligned with a longitudinal axis of the rotary steerable tool; and

the method further comprises;

(c) causing the accelerometers to measure tri-axial acceleration components of the housing; and

(d) processing said tri-axial acceleration components measured in (c) to determine at least one of a bit bounce parameter and a lateral vibration parameter.

24. The method of claim 23, wherein (d) further comprises:

(i) processing a difference between instantaneous and average axial acceleration components measured in (c) to determine the bit bounce parameter; and

(ii) processing a difference between instantaneous and average cross axial acceleration components measured in (c) to determine the lateral vibration parameter.

25. The method of claim 23, further comprising:

(e) processing said tri-axial acceleration components measured in (c) to determine borehole inclination and gravity tool face.

26. The method of claim 23, wherein the bit bounce parameter and the lateral vibration parameter are determined in (d) according to at least one equation selected from the group consisting of:

27. The method of claim 23, further comprising:

(e) telemetering the stick/slip parameter, the bit bounce parameter, and the lateral vibration parameter to a surface location.

28. A method for determining downhole dynamics parameters downhole during drilling of subterranean borehole, the method comprising:

(a) rotating a string of tools in a borehole, the string of tools including a rotary steerable tool and a drill bit rotationally coupled with a drill string, the rotary steerable tool including a shaft disposed to rotate substantially freely in a housing, the rotary steerable tool further including a rotation rate measurement device disposed to measure a rotation rate of the shaft relative to the housing, the rotation rate measurement device having at least one sensor and a plurality of markers, the sensor disposed to send an electrical pulse to a controller each time one of the markers and the sensor rotate past one another, the rotary steerable tool further including a tri-axial accelerometer set deployed in the housing;

(b) processing said electrical pulses to determine instantaneous and average rotation rates of the shaft;

(c) processing the instantaneous rotation rate to determine a stick/slip parameter;

(d) causing the accelerometers to measure tri-axial acceleration components of the housing; and

(e) processing the tri-axial acceleration components measured in (d) to determine a bit bounce parameter and a lateral vibration parameter.

29. The method of claim 28, wherein the stick/slip parameter is determined in (c) according to at least one equation of the group consisting of:

30. The method of claim 28, wherein the bit bounce parameter and the lateral vibration parameter are determined in (e) according to at least one equation selected from the group consisting of:

31. The method of claim 28, further comprising:

(f) telemetering the stick/slip parameter, the bit bounce parameter, and the lateral vibration parameter to a surface location.