Accelerometer caliper while drilling

• US 6,467,341 B1
• Filed: 04/24/2001
• Issued: 10/22/2002
• Est. Priority Date: 04/24/2001
• Status: Expired due to Term

• Current Assignee: ReedHycalog LP (NOV, Inc.)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: McCarthy, Tim, Jarvis, Brian Peter, Boucher, Marcel
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US09/841,659
• Publication Number:
  US 20020152806A1
• Time in Patent Office: 546 Days
• Field of Search: 731/524.3, 731/524.6, 731/524.8, 731/520.3, 175/45, 175/49, 175/50, 166/254.2, 166/255.2, 166/250.1
• US Class Current: 73/152.43
• CPC Class Codes: E21B 47/08 Measuring diameters or related dimensions at the borehole

Abstract

An accelerometer caliper while drilling arrangement comprising a drill bit having an axis of rotation and a gauge region, a caliper tool body, a first accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a first direction, and a second accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a second direction orthogonal to the first direction, wherein the caliper tool body and the drill bit are coupled to one another in such a manner that the first and second accelerometers are mounted in a known relationship to the drill bit.

Claims

1. An accelerometer caliper while drilling device comprising a drill bit having an axis of rotation and a gauge region, a caliper tool body, a first accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a first direction, and a second accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a second direction orthogonal to the first direction, wherein the caliper tool body and the drill bit are coupled to one another in such a manner that the first and second accelerometers are mounted in a known relationship to the drill bit.

2. The accelerometer caliper while drilling device of claim 1, wherein an additional accelerometer is mounted upon the caliper tool body.

3. The accelerometer caliper while drilling device of claim 2, wherein the additional accelerometer is mounted diametrically opposite the first accelerometer.

4. The accelerometer caliper while drilling device of claim 1, wherein at least one of the accelerometers is located at a periphery of the caliper tool body.

5. The accelerometer caliper while drilling device of claim 1, wherein the caliper tool body is located eccentrically relative to the drill bit.

6. The accelerometer caliper while drilling device of claim 1, further comprising a magnetometer.

7. The accelerometer caliper while drilling device of claim 2, wherein the cailper tool body is located eccentrically relative to the drill bit.

8. A bottom hole assembly comprising a drill bit having an axis of rotation and a gauge region, an accelerometer caliper tool body, a first accelerometer mounted upon the caliper tool body, and arranged to measure acceleration in a first direction, and a second accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a second direction orthogonal to the first direction, wherein the caliper tool body and the drill bit are coupled to one another in such a manner that the first and second accelerometers are mounted in a known relationship to the drill bit, a controller/processor arranged to receive signals from the first and second accelerometers and a mud telemetry transmitter arranged to transmit data under the control of the controller/processor.

9. The bottom hole assembly of claim 8, further comprising a magnetometer.