Rotary downlink system

• US 20050209782A1
• Filed: 03/12/2004
• Published: 09/22/2005
• Est. Priority Date: 03/12/2004
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Moriarty, Keith Alan
• Granted Patent: US 7,298,285 B2
• Time in Patent Office: Days
• US Class Current: 702/6
• CPC Class Codes: E21B 47/18 through the well fluid , e.g. mud pressure pulse telemetry
• 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 method for downlink communication with a downhole tool having a mud-powered downhole motor that includes receiving a sensor signal related to a rotational speed of a rotor in the mud-powered downhole motor, and interpreting the sensor signal to derive a downlink signal.

Claims

1. A method for downlink communication with a downhole tool having a mud-powered downhole motor, comprising:

receiving a sensor signal related to a rotational speed of a rotor in the mud-powered downhole motor; and

interpreting the sensor signal to derive a downlink signal.

2. The method of claim 1, wherein the receiving the sensor signal comprises determining a rotational speed of at least part of a bottom hole assembly.

3. The method of claim 1, further comprising varying a mud flow rate from a surface.

4. The method of claim 1, further comprising stopping a rotation of a drill string at a surface.

5. The method of claim 1, further comprising lifting a drill bit off a bottom of a borehole.

6. The method of claim 1, further comprising controlling a downhole equipment based on the derived downlink signal.

7. The method of claim 1, wherein the interpreting the sensor signal comprises computing at least one selected from a magnitude of the sensor signal, a rate of change of the sensor signal, and a temporal pattern of the sensor signal.

8. The method of claim 1, wherein the mud-powered downhole motor comprises a positive displacement mud motor.

9. The method of claim 1, wherein the mud-powered downhole motor comprises a drilling mud turbine.

10. A downlink communication system for a downhole tool, comprising:

a mud-powered downhole drilling motor disposed in the downhole tool;

at least one sensor disposed in the downhole tool for making measurements related to a rotational speed of a rotor in the mud-powered downhole motor; and

an electronics package operatively coupled to the at least one sensor and configured to interpret a downlink signal based on an output of the at least one sensor.

14. The downlink system of claim 10, wherein the at least one sensor comprises a magnetometer.

15. The downlink system of claim 10, wherein the at least one sensor comprises an accelerometer.

16. The downlink system of claim 10, wherein the at least one sensor comprises a gyroscope.

17. The method of claim 10, wherein the mud-powered downhole motor comprises a positive displacement mud motor.

18. The method of claim 10, wherein the mud-powered downhole motor comprises a drilling mud turbine.

11. The downlink system of claim 108, wherein the downhole tool comprises a bottom hole assembly connected below the mud-powered downhole motor, and wherein the at least one sensor and the electronics package are disposed in the bottom hole assembly.

12. The downlink system of claim 11, further comprising a rotary steerable system disposed in the bottom hole assembly.

13. The downlink system of claim 12, wherein the at least one sensor is disposed in the rotary steerable system