GB2170579A - Retrievable subset T.F.L. diverter switch valve - Google Patents

Abstract

A subsea switching valve comprises a plug 12 movable by an operating assembly 14 including a spring-biased fluid-operable piston 108 to connect an inlet 22 in valve body 10 with either of two outlets 24, 26. Preferably the operator assembly 14 is removably connected to the body 10 and plug 12 such that upon removal of the operator assembly, the plug is also removed for repair and replacement. <IMAGE>

Description

SPECIFICATION Retrievable subsea T.F.L. diverter switch BACKGROUND OF THE INVENTION The present invention relates to diverter switches for directing the flow of tools used in conducting various operations on remote oil and/or gas wells located subsea.

In performing completion and workover operations on subsea wells, tools are moved hydraulically through large radius flowlines connected in branched relationship. referred to as wye branches, to the wells. Tool diverter switches, usually hydraulically operated, are required at the branches in the flowlines to seiectively deflect such tools through the flowline (TFL) into the desired wells. One type of hydraulically TFL tool diverter switch is disclosed in the U.S. Patents Nos. 4,133,418 and 4,260,022 to Van Bilderbeek, and another type is disclosed in U.S. Patent No.

3,881,516 to Childers, et al.

In the TFL diverter switch of Van Bilderbeek, the diverter switch served a number of flowlines and was adapted to be lowered on a length of tubular conduit, such as drill pipe, from a vessel or platform at the top of the body of water and connected to a template on the ocean floor.

In the TFL diverter switch of Childers, et al, the diverter switch was connected to a paddle hinged to a shaft at the junction of the wye branched flowlines for alternately diverting tools through one or the other of the flowlines. While the operator assembly for operating the paddle was removeable for repair and replacement, the paddle itself remained in the flowline. If the paddle became damaged, or otherwise rendered inoperative, the flowlines themselves had to be retrieved and brought to the surface for repair. The operator assembly of this diverter switch, however, did have the advantage of being removeable and replaceable by means of a subsea manipulator, such as a remotely operated vehicle (ROV). This eliminated the need for rigs and drill string equipment since only a barge or workboat was needed to bring the ROV to the vicinity.

This invention is an improvement over the above mentioned prior art diverter switches in that the entire diverter switch, including the means located in the wye branched flowlines, is removeable and replaceable by means of an ROV.

Another improvement over the prior art diverter switches accomplished by this invention is that the diverter switch is configured to be moved and replaced by the same tools used to remove and replace conventional control valves located in the flowlines to control the flow of valve products from the selected wells.

SUMMARY OF THE INVENTION In accordance with this invention, the diverter switch includes a reciprocable plug located at the junction of branched passageways formed in a diverter body member for diverting flow through either of the branched passageways and ultimately to one of the two branched flowlines connected to the body member. An operator assembly causes a shaft connected to the diverter plug to reciprocate the plug from one position which diverts flow through one of the branched passageways to another position which diverts flow through the other branched passageway. The operator assembly includes a hydraulically operated spring biased piston to move the diverter plug from one position to the other against the bias of the spring. The operator assembly and diverter plug are removeable from the body member for repair and replacement.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified illustration of flowlines connected in a manner to service a number of subsea wells with diverter switches located at each of the wye branches and control valves located in the flowlines, Figure 2 is an elevational view of the diverter switch of this invention partially broken away to show the inner details thereof, Figure 3 is a cross-sectional view of the diverter switch with the diverter plug forming the wye connection through the branched flowlines, Figure 4 is a cross-sectional view taken along line 4-4 of Figure 3, Figure 5 is a cross-sectional elevational view taken along line 5-5 of Figure 3, Figure 6 is an exploded view of certain components of diverter switch to illustrate the details of assembly, Figure 7 is a perspective view, partially in section, illustrating the hydraulic lines in the diverter switch, and Figure 8 is an enlarged perspective detailed view illustrating the manner of connecting the hydraulic lines within the diverter switch.

DETAILED DESCRIPTION Referring to the drawings, Figure 1 illustrates a plurality of flowlines F arranged in a pattern, sometimes called a manifold, for servicing a number of subsea wells W. Two main flowlines are connected to branch lines in a wye pattern with flow diverter switches S located at the junction between the branches.

Also disclosed are control valves V located in the flowlines to control the flow of well products from any selected well. It will be recognized by those skilled in the art that the location of these valves and the layout of the manifold, as shown herein, is to illustrate a concept and that the manifold itself and the location of the flow diverter switches will be selected according to the design of the entire system. This schematic does illustrate, however, one of the important features of this invention, namely the flow diverter switches of this invention, being of the same outside configuration as the control valves, can be removed and replaced by the same tools on a subsea manipulator (ROV) as those used to remove and replace the control valves.

Turning now to Figures 2 et seq, it can be seen that the flow diverter switch S of this invention comprises two main parts -- a body member 10, also referred to as a receiver body, which contains a diverter plug 12, and an operator assembly 14 for actuating the diverter plug. The receiver body 10 and operator assembly 14 are removeably connected together by a retainer nut 16 and both the receiver body 10 and retainer nut have radially outwardly extending ears or tool lugs 18 to aid in assembling and disassembling the diverter switch. In operation, normally the receiver body is held against rotation while the retainer nut is rotated to enable the diverter switch to be handled by tools on an ROV. A split ring 20 holds the retainer nut onto the operator assembly 14 when the operator assembly is disconnected from the receiver body 10.

Turning now to the details of the first main part, the receiver body 10 and diverter plug 12, it can be seen that the receiver body 10 is cylindrical and cup-like in form open at the top and closed at the bottom and having an inlet 22 and two outlets 24 and 26 extending therefrom. The outlets are branched in wye fashion and both the inlet and outlets are conventionally welded to the selected flowlines F for the flow of fluid and tools from the inlet 22 out either of the two outlets 24 or 26.

The ends of the inlet and outlets are chamfered for welding purposes in the conventional manner and one outlet is shown welded to one flowline by way of example.

The diverter plug 12 is received within the receiver body in slideable relationship and contains two diverter passages 30 and 32 for alternately connecting the inlet 22 with the outlets 24 or 26. The diverter plug is wider on the side adjacent the outiets than it is near the inlet and the two passages which transverse the diverter plug are located one above the other (as viewed in the drawings) and are alternately connectable to the respected outlets by the reciprocal movement-of the diverter plug (upward and downward movement as viewed in the drawings). When the diverter plug is in either position connecting the inlet 22 to one of the outlets, such as 24, flow to the other outlet, such as 26, is blocked.

To guide the diverter plug 12 in its reciprocal movement, a pair of guide inserts 34 and 36 are inserted on each side of the diverter plug. These guide inserts have cylindrical outer surfaces conforming to the inner cylindrical surface of the receiver body, and have inner surfaces conforming to the shape of the diverter plug. These guide inserts are also provided with axial bores 40 and 42 and counterbores 44 and 46, respectively, to receive a pair of tubular sleeves 50 and 52 which extend through the guide inserts and outwardly of the receiver body 10 through suitable holes 54 and 56 formed in the bottom end thereof. These tubular sleeves 50 and 52 are provided with enlarged ends or heads 60 and 62 and are positioned in the counterbores 44 and 46 and are welded to the bottom of the receiver body as shown at 64.These tubular sleeves serve to retain the guide inserts within the receiver body as a permanent part thereof. Also, as part of the receiver body, suitable hydraulic tubes or lines 66 and 68 are inserted through the tubular inserts and extend outwardly beyond the bottom of the receiver body. One line 66 is dedicated as the exhaust outlet and the other line 68 is dedicated as the pressure inlet to be connected to a suitable source of hydraulic fluid under pressure and to an exhaust line, respectively, in the well system. The upper level of the lines 66 and 68 are enlarged to form sockets 70 and 72 to connect the operator assembly hydraulically to the lines 66 and 68. One socket 70 for line 66 is shown in Figure 8. Also shown in this Figure is an 0ring seal 74, located in the socket, to prevent leakage out of the socket.

The diverter plug 12 is connected to the operator assembly 14 and, in the embodiment illustrated, is provided with an integral upstanding cylindrical projection or tongue 76 which is internally bored and threaded as at 80 to receive an externally threaded shaft 82 connecting the diverter plug 12 to the operator assembly 14. This cylindrical tongue also couples a connecting ring 84 to the operator assembly. This coupling is accomplished through a concentric bore 86 in the connecting ring to receive the cylindrical tongue 76.

Connecting ring 84 is also provided with a cylindrical projection or tongue 90 coaxial with the tongue 76 on the diverter plug and projecting in the same direction. Tongue 90 is also provided with a central bore 92 to receive the shaft 82 in slideable relationship. An O-ring seal 94 in a suitable groove seals the receiver body and plug from the operator assembly by sealingly engaging the shaft 82. An additional O-ring seal 96 with a suitable groove is positioned about the outer periphery of the retainer ring to sealingly engage the inner wall of the receiver body to prevent leakage from the receiver body. Placed over the tongue 90 is a long, hollow, relatively thin tube 100 connected at its upper end to an end cap 102 to form a chamber 104 which contains a helical spring 106 surrounding shaft 82 and a piston 108 connected to the upper end of the shaft 82.Both ends of the tube 100 and the piston 108 are sealed in any suitable manner. For example, the piston 108 is provided with an O-ring seal 110, the upper end of the tube 100 may be welded to the end cap 102 and an O-ring seal 112 is positioned in a suitable groove in the tongue 90.

the piston 108 divides the chamber 104 into two subchambers; a fluid pressure chamber 114 and an exhaust chamber 116. The pressure chamber 114 is connected by a passage 120 in the end cap 102 to a tubing or line 122. This tubing 122 extends downwardly through the connecting ring 84 and is provided with a stab 124 (see Figure 8) which is received in the aforementioned pressure socket 70 to connect the tubing 122 to the pressure tube 66. A port 126 in the wall of the tube 100 connects the exhaust chamber 116 to a second vertical tubing 130 which extends downwardly through a second aperture 134 in the connecting ring 84. This tubing 130 is provided with a stab to be inserted into a socket to connect this latter tube to exhaust.The connecting ring 84 is provided with two bores 132 and 134 which are both counterbored as at 136 and 140 to accommodate the tubes and to retain and align the stabs for insertion into their respective sockets. Thus, in Figure 8 it can be seen that stab 124 is held by a pair of snap rings 142 and 144 located on each side of bore 136 to retain and align the stab on the retainer ring.

Since the stab and socket on the exhaust side is the same as those components on the pressure side of the diverter switch, only the pressure side components will be described in detail. Turning now to Figure 5, it can be seen that suitable circular metallic gaskets 146 and 148 surround the bores in the connecting ring 84, and in the heads 60 and 62 of tubular sleeves 50 and 52, to seal the interface between the connecting ring 84 and the heads 60 and 62.

Finally, the operator assembly further includes a second hollow cylindrical tube 150 forming an outer housing, which encompasses the chamber 104 and the tubes 122 and 130 and is connected to the end cap 102 in any suitable manner. In the embodiment shown, the housing is suitably affixed, as by welding, to a cap ring 152 which is centrally bored at 154 to be inserted over an extension 156 on the end cap and affixed thereto by set screws 160. The lower end of the housing is provided with a radially extending lip 162 engageable by the retainer nut 16 to complete the diverter switch.

Thus, from the foregoing it can be seen that the bias of the spring urges the piston and, hence, the diverter plug into its upper position connecting the inlet 22 to the outlet 24 and at the same time blocking the flow of fluid out outlet 26. When hydraulic fluid under pressure is introduced from a source of pressure into the pressure chamber 114, the bias of the spring 106 is overcome and the diverter plug is moved to its downward position connecting the inlet 22 to the outlet 26 and at the same time blocking the flow of fluid from outlet 24.

From the foregoing it can also be appreciated that the unthreading of the retainer nut 16 will permit the diverter plug 12, connecting ring 84 and the remainder of the operator assembly 14 to be disconnected from the receiver body 10 for repair or for the replacement with a similar operator assembly into the receiver body. It can be appreciated that there is then no need to retrieve the flowlines since the working parts of the diverter switches are completely removeable.

Claims (13)

1. An apparatus for diverting flow from one conduit to other conduits comprising; a diverter receiver body having branched passageways which form an inlet connectable to said one conduit and two outlets connectable to said other conduits, a diverter plug arranged at the junction of said branched passageways and moveable from one position in which said inlet is connected to one of said outlets and the second outlet is blocked to a second position in which said inlet is connected to said second outlet and the first outlet is blocked, an operator assembly including a shaft connected to said diverter plug, said operator assembly further including, a hydraulically operable piston sssembly having a chamber and piston means reciprocal in said chamber in response to spring bias and fluid pressure and connected to said shaft whereby said diverter plug is biased to one position by said spring bias and moveable to said second position by said piston in response to said fluid pressure.

2. The apparatus as claimed in Claim 1 wherein said operator assembly is removeably connected to said receiver body and to said diverter plug such that, upon removal of said operator assembly, said diverter plug is also removed.

3. The apparatus as claimed in Claim 2 wherein said receiver body is hollow, cylindrical and cup-like in form open at one end and closed at the other, and includes guide means within said receiver body to guide the insertion and removal of said diverter plug to and from said receiver body.

4. The apparatus as claimed in Claim 3 wherein said receiver body includes receiver hydraulic connecting means for connecting said piston assembly hydraulically to a source of fluid under pressure and to exhaust.

5. The apparatus as claimed in Claim 4 wherein said receiver hydraulic connecting means are disconnectable from said operator assembly upon removal of said operator assembly from said receiver body.

6. The apparatus as claimed in Claim 5 wherein said operator assembly includes means for connecting said piston assembly to said receiver hydraulic connecting means.

7. The apparatus as claimed in Claim 6 wherein said operator assembly includes a housing encompassing said chamber and piston assembly and means for connecting said operator assembly to said receiver body.

8. The apparatus as claimed in Claim 7 wherein said housing and said receiver body are threadably connected together.

9. Apparatus for diverting flow from one conduit into other conduits in a subsea environment comprising; a receiver body having branched passageways connected to said conduits, diverter means arranged at the junction of said branched passageways and moveable from one position in which flow through one of said passageways is blocked to another position in which flow through another passageway is blocked and vice versa, an operator assembly including, a hydraulically operable piston assembly having a chamber and piston means reciprocal in said chamber, said piston means arranged to be responsive to fluid pressure applied to said piston means, bias means connected to said piston means for urging said piston means in a direction counter to the movement of said piston in response to fluid pressure, and means connecting said operator assembly to said receiver body and to said diverter means such that disconnection and removal of said operator assembly from said receiver body also removes said diverter means.

10. The apparatus as claimed in Claim 9 wherein said last mentioned means is a shaft connected to said piston means and to said diverter means.

11. The apparatus as claimed in Claim 10 wherein said chamber is divided by said piston means into a pressure chamber and an exhaust chamber and wherein said receiver body and operator assembly include hydraulic means for connecting said pressure chamber to a source of fluid under pressure and the exhaust chamber to an exhaust.

12. The apparatus as claimed in Claim 11 wherein said hydraulic.means in said operator assembly is disconnectable from said hydraulic means in said receiver body upon disconnection of said operator assembly from said receiver body.

13. An apparatus for diverting flow from one conduit to other conduits, substantially as hereinbefore described with reference to the accompanying drawings.