WO1996030621B1

WO1996030621B1 - Flow control tool

Info

Publication number: WO1996030621B1
Application number: PCT/GB1996/000667
Authority: WO
Filing date: 1996-03-20
Publication date: 1996-11-14
Anticipated expiration: 1997-09-24

Abstract

A tool for incorporation in a drill string has an outer body (11, 12, 13) and a spool (17, 18, 19) rotationally and slidably mounted within the body. A cam groove (20) is formed on camming component (17) of the spool and interacts with pins (21) to cause uni-directional spool rotation through a number of pre-set angular positions as the spool is reciprocated. The valving component (18) of the spool is closed internally by wall (26) and has orifices (25) which come into and out of registration with body openings (29) as the spool is moved through its pre-set positions. When in registration, flow into the tool will leave the tool radially outwardly through openings (29); but when out of registration, the flow will be into chamber (28) of body central component (12), and back into the valving component (18) downstream of wall (26) through apertures (27).

Claims

AMENDED CLAIMS[received by the International Bureau on 3 October 1996 (03.10.96); original claims 1-12 replaced by new claims 1-14 (3 pages)]

1. A flow control tool for incorporation in an underground string, comprising an elongate hollow outer body, a hollow inner spool mounted within the outer body and movable both axially and rotationally with respect thereto, motion control means arranged between the body and the spool to effect rotation of the spool relative to the body sequentially through a plurality of pre-set angularly spaced positions upon axial reciprocation of the spool, at least one spool orifice extending through a side wall thereof and which comes into communication with an opening through the body at a first pre-set position of the spool and is out of communication at a second pre-set position, spring means urging the spool in the axial direction opposed to the pumped fluid flow direction to a third pre-set position where flow through the spool is closed off, and the spool being arranged such that fluid under pressure and flowing axially therethrough moves the spool axially against the action of the spring.

2. A flow control tool as claimed in claim 1, wherein the spool has an internal dividing wall downstream of the or each orifice therein, and there is at least one flow re-entry aperture leading to the interior of the spool downstream of said wall, the body defining an internal chamber with which both the or each spool orifice and the or each spool aperture communicate when the spool is in a second pre-set position, whereby fluid flow may be essentially axially through the tool.

3. A flow control tool as claimed in claim 2, wherein flow passages are provided to permit partial flow through the tool and partial outward flow through a communicating spool orifice and body opening, when the spool is set to a third pre-set position. 1 3

4. A flow control tool for incorporation in an underground string, comprising an elongate hollow outer body, a hollow inner spool mounted within the outer body and movable both axially and rotationally with respect thereto, motion control means arranged between the body and the spool to effect rotation of the spool relative to the body sequentially through a plurality of pre-set angularly spaced positions upon axial reciprocation of the spool, at least one spool orifice extending through a side wall thereof and which comes into communication with an opening through the body at a first pre-set position of the spool and is out of communication with said opening at a second pre-set position, the spool and body together defining a chamber therebetween downstream of the body opening and with which chamber the at least one spool orifice communicates when the spool is in its second pre-set position, spring means urging the spool in the axial direction opposed to the pumped fluid flow direction, and the spool being arranged such that fluid under pressure and flowing axially therethrough moves the spool axially against the action of the spring.

5. A flow control tool as claimed in claim 4, wherein the spool is provided with an internal dividing wall downstream of the at least one orifice therein, and when the spool is in its second pre-set position, fluid flowing axially into the body leaves the spool through the at least one spool orifice to flow into the chamber and from there to flow axially along the tool to the downstream end thereof.

6. A flow control tool as claimed in any of the preceding claims, wherein the motion control means comprises a cam surface on one of the spool and the body, and a cam follower on the other of the spool and the body. U

7. A flow control tool as claimed in claim 6, wherein the cam surface comprises a camming groove formed in a cylindrical surface of one of the spool and body.

8. A flow control tool as claimed in claim 7, wherein the cam follower comprises a pin mounted on a cylindrical surface of the other of the spool and body and confronting said surface in which is formed the camming groove.

9. A flow control tool as claimed in claim 7 or claim 8, wherein the camming groove defines at least one first and one second pre-set positions spaced both axially and angularly from each other.

10. A flow control tool as claimed in claim 7, wherein the camming groove defines two first and two second pre-set positions arranged alternately.

11. A flow control tool as claimed in any of the preceding claims, wherein the motion control means is arranged to effect uni-directional rotation of the spool with respect to the body upon reciprocation of the spool.

12. A flow control tool as claimed in any of the preceding claims, wherein the or each spool orifice comes into and out of direct registration with a respective body opening by axial displacement of the spool between its first and second pre-set positions.

13. A flow control tool as claimed in any of claims 7 to 9, wherein there are four equi-spaced spool orifices and four corresponding body openings.

14. A flow control tool as claimed in any of the preceding claims, wherein the two axial ends of the hollow body are provided with string couplers, whereby the body may form a part of a string.