WO2014011639A1

WO2014011639A1 - Variable inner diameter shear and seal ball valve

Info

Publication number: WO2014011639A1
Application number: PCT/US2013/049731
Authority: WO
Inventors: Oguzhan Guven; Gary L. Rytlewski
Original assignee: Schlumberger Canada Limited; Services Petroliers Schlumberger; Schlumberger Holdings Limited; Schlumberger Technology B.V.; Prad Research And Development Limited; Schlumberger Technology Corporation
Priority date: 2012-07-10
Filing date: 2013-07-09
Publication date: 2014-01-16
Also published as: BR112014033032A2

Abstract

Embodiments may take the form of a valve configured to shear and seal. One embodiment may take the form of a shear and seal valve having an actuatable member rotatably displaceable between an open position and a closed position. The actuatable member includes an aperture extending therethrough which varies in size along the length of the aperture. A first part of the actuatable member includes a first portion of the aperture and a second part of the actuatable member includes a second portion of the aperture. The second portion of the aperture has a larger volume than the first portion.

Description

VARIABLE INNER DIAMETER SHEAR AND SEAL BALL VALVE

BACKGROUND

[0001 ] A subsea test tree enables well testing and well clean-up operations to be conducted from an offshore floating rig. The subsea test tree is the primary safety device in well operations and provides fast acting and reliable means to: (1 ) shut-in the well with two barriers and prevent discharge of the landing string contents into riser, and (2) disconnect the landing string from the test string. Ball valves are widely used as the primary barrier of subsea test trees.

[0002] Additionally, in order to perform certain well operations, various conveyance media (coil tubing, slickline and wireline) may be run through the subsea test tree. The subsea test tree cuts through these media to shut in the well.

SUMMARY

[0003] Embodiments may take the form of a valve configured to shear and seal. One embodiment may take the form of a shear and seal valve having an actuatable member rotatably displaceable between an open position and a closed position. The actuatable member includes an aperture extending therethrough which varies in size along the length of the aperture. A first part of the actuatable member includes a first portion of the aperture and a second part of the actuatable member includes a second portion of the aperture. The second portion of the aperture has a larger volume than the first portion.

[0004] Another embodiment may take the form of a system including a subsea test tree and a shear and seal valve. The shear and seal valve includes a ball rotatable between an open position and a closed position. The ball has an aperture with a variable cross-sectional area along its length. A first end of the aperture has a first cross-sectional area that is smaller than that of a second cross-sectional area of a second end of the aperture.

[0005] Yet another embodiment may take the form of a method including actuating an actuatable member to move from an open position to a closed position, cutting a conduit passing through the actuatable member with a first portion of an aperture through which the conduit passes and sealing the valve using a second portion of the actuatable member and a sealing member of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 illustrates an example subsea test tree system.

[0007] Fig. 2 is a cross-sectional view of a ball valve with separate shear and seal surfaces for use in the subsea test tree of Fig. 1 .

[0008] Fig. 3 illustrates the ball valve of Fig. 2 in an open position with a coil tubing through it.

[0009] Fig. 4 illustrates the ball valve of Fig. 2 upon completion of shearing.

[0010] Fig. 5 illustrates the ball valve of Fig. 2 in a closed position.

[001 1 ] Fig. 6A and Fig. 6B illustrate another embodiment of a variable inner diameter ball for use in a ball valve with separate shear and seal surfaces for use in the subsea test tree of Fig. 1 .

[0012] Fig. 7A and Fig. 7B illustrate yet another embodiment of a variable inner diameter ball for use in a ball valve with separate shear and seal surfaces for use in the subsea test tree of Fig. 1 .

DETAILED DESCRIPTION

[0013] A ball valve can be used as a well shut-in element of the subsea test trees in the industry. Some ball valves may be generally capable, to some extent, to shear coil tubing or wireline. When conventional ball valves actuate, the leading surface of the ball engages and shears the coil tubing or wireline, and during the shearing process, this leading surface may be vulnerable to damage. Resulting damage reduces the effectiveness of, or impedes the ability of that leading surface to provide a sealing surface once the ball valve is actuated to a closed orientation. As a result, leakage could occur after a shear operation.

[0014] Disclosed is a ball valve which reliably and repeatably cuts coil tubing/wireline and provides a gas tight seal afterwards by utilizing independent cutting and sealing surfaces. As such, a single device (e.g., ball valve) may operate to both cut or shear, and seal.

[0015] The device may be used as the primary barrier and shear mechanism of the subsea test tree. The device may be configured for dual purposes: shearing and sealing. To that end, the disclosed device utilized separate shearing and sealing surfaces. For example, in some embodiments, an upper portion of the ball valve may generally be used for cutting and a lower portion of the ball valve may generally be used for seal. In some embodiments, an aperture extending through a ball of a ball valve may have different dimensions at one end from the other. For example the aperture may have a first circumference at a first end and a second, larger circumference at the second end. The first end may be used for cutting as the ball rotates and the second end allows a cut member to fall through the valve and eventually seal the ball valve.

[0016] Turning to the drawings and referring initially to Fig. 1 , a subsea test tree system 100 is illustrated. The system 100 may include surface components and subsurface component. For the sake of conciseness, not all the surface or subsurface components are described and/or illustrated. Additionally, the specific function of the components may not be discussed in detail, but would be understood and appreciated by those skilled in the art. In an actual implementation, more, fewer and/or different components may be used. As such, the system 100 is provided as an example context in which the ball valve may be implemented. Indeed, it should be appreciated that the ball valve may be implemented in different and varied contexts, and the description herein should not be understood as limiting the applicability of the ball valve to a particular context and/or system.

[0017] A wireline blow out preventer (BOP) 1 10 and a flowhead 120, may be located at, near or above the sea's surface. Additionally, hydraulic/electrical consoles 132 and a chemical injection skid 134 may be positioned on a rig floor 130 at, near or above the surface.

[0018] Lubricator valves 140 may be located beneath the rig and within a riser 150. Tubing may extend within the riser 150 and through a subsea BOP stack 170, a subsea test tree 180 and below a mudline 190. One or more safety valves 192 may be located below the mudline along with drill stem testing (DST) /completion string components 194.

[0019] Fig. 2 is a cross-sectional view of an example ball valve 200 that may provide both shearing and sealing functions within the subsea test tree system 100. In some embodiments, the ball valve 200 may be located at a subsea location, such as at, near or within the BOP stack 170 or the subsea test tree 180. Generally, the ball valve 200 may include separate/independent shear and seal surfaces. An internal bore 210 through a ball 21 1 of the ball valve 200 may have a variable inner diameter, as shown in FIG. 2. A larger inner diameter portion 212 provides a sealing surface 213 and interfaces with a ball seal 214. The sealing surface 213 may generally remain unblemished or unchanged by a cutting operation and may provide a sealing surface for the valve 200. The ball seal 214 may take any suitable form and in some embodiments may take the form of an elastomeric material. In some embodiments, the seal may be created by a tight fit between the ball and the valve housing. That is, there may be no elastomeric material in the valve. [0020] The smaller inner diameter portion 216 provides a shearing surface 217 and interfaces with a cutting insert 218. The cutting insert 218 may be configured to provide a sharpened and/or hardened edge to help facilitate the shearing process. In some embodiments, one or more surfaces of the smaller inner diameter portion 216 (e.g., the shearing surface 217) and the cutting insert 218 may be treated and/or coated with another material to help improve its ability to cut. In some embodiments, one or more surfaces may therefore include a material different from that of the rest of the ball valve 200. For example, a tungsten, diamond or other suitable coating or material may be provided. Additionally, in some embodiments, the cutting insert may be an integral part of the valve housing.

[0021 ] For various well operations, a conveyance medium such as coil tubing, slickline or wireline, for example, may be run through the ball valve 200. In FIG. 3, the medium is shown as a coil tubing 300. It should be appreciated, however, that other media may run through the ball valve 200 and the ball valve may cut and shear the media.

[0022] When the ball valve 200 is actuated to a closed configuration, the smaller shear inner diameter portion 216 of the ball 21 1 , as shown in FIG. 4, engages and shears the medium (coil tubing 300) while the seal inner diameter portion 212 of the ball valve 200 allows the sheared medium to fall through, as shown in FIG. 4. In this process, the shear edge 217 of the ball 21 1 may be damaged by the cutting process, but any such damage does not affect the sealing surface and therefore the sealing capability of the ball valve 200, as the sealing surface of the valve is not exposed to shear forces. As the ball valve 200 completes its rotation, the undamaged seal edge of the ball valve slides through the ball seal without causing seal damage, as shown in FIG. 5.

[0023] Two variations of the variable inner diameter ball valve are shown in FIGS. 6 and 7. In FIG. 6A, a ball 600 of the ball valve is shown having a larger inner diameter portion 602 having a generally oval shape. FIG. 6B shows the smaller diameter portion 604 which may be used as the shearing end of the ball 600. [0024] FIG. 7A illustrates a ball 700 having a generally circular or conical shaped larger inner diameter portion 702. FIG. 7B illustrates the smaller inner diameter portion 704 of the ball 700, which may be used as the shearing end of the ball. It should be appreciated that the particular shape of the inner diameter portion and the outer diameter portion of the balls 600, 700 may take any suitable shape. That is, they may take a generally triangular, square, hexagonal or other shape. In some embodiments, as with the ball 600, the smaller inner diameter portion and the larger inner diameter portion may take different shapes.

[0025] Additionally, as illustrated in FIGS. 6 and 7, different engagement members may be implemented to help mount the ball within the ball valve and/or to rotate the ball. For example, in FIGS. 6A and 6B, an engagement member 606 may protrude from the ball. The engagement member 606 may engage a housing of the ball valve to secure the ball within the ball valve. In FIGS. 7A and 7B, a slotted engagement member 706 may be provided. The slotted engagement member 706 may receive an actuating member (not shown) of the ball valve and may actuate (e.g., rotate) the ball within the ball housing. It should be appreciated that different types of engagement members may be implemented for a single ball to enable actuation of the ball. Further, any suitable actuation system or device may be implemented to actuate the ball valve. For example, the ball valve may be actuated by an electrical motor, hydraulic power, electro-hydraulic system, or other suitable actuating mechanism.

[0026] While various embodiments have been described herein with respect to a limited number of examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments and variations thereof can be devised which do not depart from the scope disclosed herein. Accordingly, the scope of the claims should not be unnecessarily limited by the present disclosure.

Claims

CLAIMS What is claimed is:

1 . A shear and seal valve comprising:

an actuatable member rotatably displaceable between an open position and a closed position, the actuatable member having an aperture extending therethrough, a size of the aperture varying along the length of the aperture;

a first part of the actuatable member having a first portion of the aperture; and a second part of the actuatable member having a second portion of the aperture, wherein the second portion of the aperture has a larger volume than the first portion.

2. The valve of claim 1 , wherein the first portion of the aperture is configured to cut a conduit extending through the aperture as the actuatable member moves from an open position to a closed position.

3. The valve of claim 1 , wherein a second part of the actuatable member comprises a sealing surface.

4. The valve of claim 3, further comprising a sealing member, wherein the sealing member and the sealing surface interface to create a seal.

5. The valve of claim 1 , wherein the first portion of the aperture comprises a circular cross-sectional shape.

6. The valve of claim 1 , wherein the second portion of the aperture comprises an oval or non-circular cross-sectional shape.

7. The valve of claim 1 , wherein the second portion of the aperture comprises a circular cross-sectional shape.

8. The valve of claim 1 , wherein a cross-sectional shape of the first portion is different from the cross-sectional shape of the second portion.

9. The valve of claim 1 , wherein the section portion of the aperture provides clearance for a coiled tubing to fall after a first portion cuts through the coiled tubing.

10. The valve of claim 1 , wherein a cross-sectional shape of the first portion is the same as the cross-sectional shape of the second portion.

1 1 . The valve of claim 1 , further comprising an engagement member for mounting the actuatable member within a housing of the valve.

12. The valve of claim 10, wherein the engagement member protrudes from the actuatable member.

13. The valve of claim 10, wherein the engagement member is configured to receive a corresponding member from a housing of the valve.

14. The valve of claim 1 , wherein the first portion of the aperture comprises a hardened material.

15. The valve of claim 1 , wherein a cutting insert of a valve housing comprises a hardened material.

16. The valve of claim 1 , wherein at least one of the first portion of the aperture and a cutting insert of a valve housing comprises a material different from that of at least one of the valve housing and the actuatable member.

17. A system comprising:

a subsea test tree;

a shear and seal valve comprising:

a ball rotatable between an open position and a close position, the ball having an aperture with a variable cross-sectional area along the length of the aperture, wherein a first end of the aperture has a first cross-sectional area that is smaller than that of a second cross-sectional area of a second end of the aperture.

18. The system of claim 1 , wherein the first end of the aperture and the second end of the aperture have a different cross-sectional shape.

19. The system of claim 1 , wherein at least one surface of the ball and a surface of the housing comprises a material different from that of the ball or the valve housing.

20. A method comprising:

actuating an actuatable member to move from an open position to a closed position; cutting a conduit passing through the actuatable member with a first portion of an aperture through which the conduit passes; and

sealing the valve using a second portion of the actuatable member and a sealing member of the housing.