Wellbore caliper with maximum diameter seeking feature

Patent metadata

Field	Value
Publication number	US-9803468-B2
Application number	US-201414565184-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Aug 29, 2012
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A wellbore caliper includes an actuator housing pivotally connected at one end to a well logging instrument housing and an actuator disposed in the housing and operable to extend and retract laterally extensible measuring arms.

First claim

What is claimed is:

1. A wellbore caliper, comprising:
an actuator housing pivotally connected at one end to a well logging instrument housing;
an actuator disposed in the housing and operable to extend and retract laterally extensible measuring arms, wherein the actuator housing is substantially neutrally buoyant in a wellbore.

2. The caliper of claim 1 wherein the actuator comprises a motor and ball screw.

3. The caliper of claim 1 wherein the actuator comprises a biasing element.

4. The caliper of claim 3 wherein the biasing element comprises a spring.

5. The caliper of claim 1 further comprising a latch disposed between the measuring arms, the latch configured to retain the measuring arms in a closed position.

6. The caliper of claim 5 further comprising a linkage coupled to one end of the actuator rod, the linkage configured to translate longitudinal motion of the actuator into lateral motion of the measuring arms.

7. The caliper of claim 6 wherein the position sensor comprises a linear variable differential transformer.

8. The caliper of claim 1 further comprising an actuator rod coupled to the actuator and arranged to move longitudinally with respect to the actuator housing.

9. The caliper of claim 1 further comprising a position sensor operatively coupled to the actuator.

10. A method for well logging, comprising:
moving a well logging tool along an interior of a wellbore drilled through formations, the well logging tool comprising a caliper, the caliper comprising an actuator housing pivotally connected at one end to a well logging instrument housing, an actuator disposed in the housing, wherein the housing is substantially neutrally buoyant in the wellbore and operable to extend and retract laterally extensible measuring arms; and
measuring an internal dimension of the wellbore by determining a lateral extension of the measuring arms.

11. The method of claim 10 wherein the actuator comprises a motor and ball screw.

12. The method of claim 10 wherein the actuator comprises a biasing element.

13. The method of claim 12 wherein the biasing element comprises a spring.

14. The method of claim 10 further comprising a latch disposed between the measuring arms, the latch configured to retain the measuring arms in a closed position.

15. The method of claim 14 further comprising moving the caliper tool through a selected diameter opening to close the arms about the latch and to return the actuator housing to a fully retracted position against a chassis of the caliper tool.

16. The method of claim 15 further comprising moving a linkage coupled to one end of the actuator rod, the linkage configured to translate longitudinal motion of the actuator into lateral motion of the measuring arms.

17. The method of claim 10 further comprising moving an actuator rod coupled to the actuator and arranged to move longitudinally with respect to the actuator housing.

18. The method of claim 17 further comprising determining a position of the actuator using a position sensor operatively coupled to the actuator.

19. The method of claim 17 wherein the position sensor comprises a linear variable differential transformer.

Assignees

• Schlumberger Technology Corp

Inventors

• Sallwasser Alan James

Classifications

• G01B5/08

  for measuring diameters {(G01B5/0035 takes precedence; measuring radius of curvature G01B5/213)} · CPC title

• G01B7/13

  Internal diameters · CPC title

• G01M3/005

  using pigs or moles (G01M3/246, G01M3/2823 take precedence) · CPC title

• G01B5/12

  internal diameters · CPC title

• E21B47/08 Primary

  Measuring diameters or related dimensions at the borehole · CPC title