CA2494229A1

CA2494229A1 - Adjustable downhole tool

Info

Publication number: CA2494229A1
Application number: CA002494229A
Authority: CA
Inventors: Mark Alexander Russell; Andrew Ollerenshaw
Original assignee: Toolbox Drilling Solutions Ltd
Current assignee: Toolbox Drilling Solutions Ltd
Priority date: 2004-02-02
Filing date: 2005-01-25
Publication date: 2005-08-02
Anticipated expiration: 2025-01-25
Also published as: GB0402220D0; GB2410510A; GB2410510B; CA2494229C; DE102005004606A1

Abstract

An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, deactivated position and a second activated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel.
Castellations (l8a,b, 69a,b) are on the body and facing edge or edges of the sleeve so that, when the castellations are in phase, the mandrel is prevented from travelling from said first to second position, and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50). The piston is axially slidable with respect to the mandrel.
A circumferential barrel cam (56) is defined on the piston, a cam follower (58) being disposed in the mandrel but within the confines of the barrel cam so that axial movement of the piston with respect to the mandrel results in corresponding rotation of the piston with respect to the mandrel. Gears (61) in the barrel transmit rotation of the piston to the sleeve to move the sleeve between said activated and deactivated positions.

Claims

1. An adjustable down-hole tool comprising:
a body having a through bore;
a mandrel having a through bore axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring between two positions, one being a first, deactivated position and the other a second activated position;
a sleeve between the body and mandrel limiting movement of said mandrel between said positions;
at least two sets of castellations, one set on the sleeve and the other set on a facing edge of the body or mandrel so that, when the castellations are in phase, the mandrel is prevented from travelling from said first to second position and, when they are out of phase, they interdigitate and the mandrel is not prevented from travelling from said first to second position; and a control piston to rotate the sleeve relative to said facing edge between said in-phase and out-of-phase positions, the piston being movable by fluid pressure in the tool against the action of a second return spring;
wherein said control piston is slidable in the mandrel, the mandrel carrying rotation transmitters that are in contact with both the piston and sleeve, whereby rotation of the piston relative to the mandrel rotates the sleeve relative to the mandrel.

2. A tool as claimed in claim 1, in which said rotation transmitters are carried by the mandrel internaediate its ends.

3. A tool as claimed in claim 2, in which said rotation transmitters are between axially spaced seals of the piston against the bore of the mandrel.

4. A tool as claimed in claim 1, 2 or 3, in which said rotation transmitters comprise a gear rotationally journalled in the mandrel about an axis parallel the throughbores, both the piston and sleeve having a rack engaged with the gear.

5. A tool as claimed in claim 4, in which a plurality of said gears are disposed around the circumference of the mandrel.

6. A tool as claimed in any one of claims 1-5, in which said tool is a drill-string stabiliser and said mandrel has wedge surfaces to engage corresponding surfaces on radially disposed pistons slidable in the body, whereby, when the mandrel moves from said deactivated to said activated position, the pistons extend from the body increasing the working diameter of the stabiliser.

7. A tool as claimed in any one of claims 1-6, in which a circumferential barrel cam is defined in one of said piston and mandrel, a cam follower being disposed in the other of said piston and mandrel, the follower being within the barrel cam so that axial movement of the piston with respect to the mandrel results in corresponding rotation of the piston with respect to the mandrel.

8. A tool as claimed in claim 7, in which a separate component of the piston is rotationally freely, but axially fixedly, mounted in the piston, which component carries said barrel cam or follower, said separate component driving said rotation transmitters on rotation of said component in response to axial movement of the piston in said mandrel.

9. A tool as claimed in claim 7 or 8, in which the barrel cam is shaped so that movement of the piston in one axial stroke and return thereof results in relative rotation of the sleeve and said facing edge from a said in-phase position to a said out-of phase position or vice versa.

10. A tool as claimed in any one of claims 1-9, in which said first return spring is sufficiently stronger than said second return spring to ensure that, when said mandrel is in said deactivated position, a rise in hydraulic pressure in the tool results in movement of the piston before movement of the mandrel.

11. A tool as claimed in claim 7, 8 or 9, in which a spring loaded detent between said mandrel and body retains the mandrel in said deactivated position until a threshold hydraulic pressure has been exceeded, which pressure is greater than that required to move said piston.

12. A tool as claimed in claim 11, in which said detent comprises a plunger in a radial bore of the mandrel or body, spring biased against a lip of the body or mandrel respectively.

13. A tool as claimed in claim 12, in which said lip is of a circumferential groove around the mandrel.

14. A tool as claimed in any one of claims 1-13, in which said facing edge is in the body.

15. A tool as claimed in any one of claims 1-14, in which the mandrel is sealed to the body about first and second circumferences, the first being a larger circumference upstream, in terms of fluid flow through the tool, of the second, smaller circumference.

16. A tool as claimed in claim 15, in which the piston has a through bore and is sealed to the mandrel about third and fourth circumferences, the third being a larger circumference upstream, in terms of fluid flow through the tool, of the fourth, smaller circumference.