GB2600755A

GB2600755A - Valve body access adapter

Info

Publication number: GB2600755A
Application number: GB2017676.4A
Authority: GB
Inventors: Mcgennis Eamonn
Original assignee: Shelf Solutions Ltd
Current assignee: Shelf Solutions Ltd
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2022-05-11
Anticipated expiration: 2040-11-09
Also published as: GB202017676D0; GB2600755B

Abstract

A valve body access adapter 10 for connecting to a valve body 12, to provide a fluid flow path 16, between a first fluid reservoir and a second fluid reservoir, comprising a cylindrical mandrel 10, adapted to fit inside the cylindrical cavity within a valve body, to form a pressure seal at two locations within the valve body, such that fluid flow in the fluid flow path between the first fluid reservoir and the second fluid reservoir is permitted. A valve body adapter comprising a cylindrical spool, and methods of removing a valve bonnet are also claimed. The valve body access adapter may have a vent valve.

Description

Valve Body Access Adapter The present invention concerns apparatus and methods that allow a valve body to be used as a retrofit fluid access point which can be incorporated into retrofit fluid flow systems. In particular, it allows the valve cavity, within a valve body of gate valves, included in piping systems, to be used for fluid injection and fluid recovery purposes.

When it becomes necessary to access existing fluid systems to either inject or recover fluids, there is usually the requirement to break into the existing pipework, unless there is a suitable access point pre-installed. In the oil and gas industry, such pre-installed access points are often referred to as hot stabs, where they allow for easy fluid access into existing systems, in particular in subsea oil and gas installations.

Where suitable hot stab access points do not exist, it can be a complex process to open up pipework and valve systems to make the access arrangements required. This is the case especially with legacy subsea systems, where it is often difficult to complete retrofit arrangements with Work-class Remotely Operated Vehicles (WROV). This access problem can be especially acute in the case of decommissioning oil and gas facilities when it becomes necessary to flush and clean pipework, and systems before removal and recovery.

The present invention simplifies fluid access arrangements by allowing any valve body with a cylindrical internal cavity to be used as a fluid access point. This is achieved by removing the valve bonnet from the valve body, removing all the valve components from inside the valve body and then inserting the valve body access adapter described herein so that it seals on the inside of the valve body. This creates a pressure fight fluid path into the internal bore that passes through the valve body.

The adapter may also be arranged to seal on the top of the valve body in the same manner as the original valve bonnet. In this arrangement the adapter may be attached to the top of the valve body using the same fittings that held the original valve bonnet.

To ensure the adapter remains in place in the valve cavity the adapter is fitted with a pressure equalisation port that ensures the pressure at the bottom of the valve cavity is vented to the ambient pressure external to the valve cavity. In this way the adapter is pressure balanced allowing it to remain in the valve cavity with minimum axial load along the axis of the adapter.

The adapter may also be fitted with a set of gripping devices of known types that grip the wall within the valve body's cylindrical cavity to secure the adapter within the valve body.

The valve body access adapter is generally cylindrical in shape and may be configured to fit any cylindrical valve cavity of known types. In particular the adapter may be configured for use subsea where the invention relates to underwater stab connections known to the art as hot stab connectors usually deployed using WROV or divers. In particular the pressure vent port built into the adapter allows the adapter to act as a pressure balanced hot stab even in a closed cavity where internal pressure would normally eject any conventional hot stab.

The adapter is fitted with a set of two seals that seal within the valve body where the top seal avoids flow between the interior of the adapter and the external environment. The bottom seal avoids flow between the interior of the adapter and the bleed port that vents the bottom of the valve cavity.

The exterior of the valve body may have any known form including where it is integrated into a valve block or as an individual component that is part of a piping system.

In accordance with the first aspect of the invention there is provided an apparatus and method for connecting to a valve body, to provide a fluid flow path, between a first fluid reservoir and a second fluid reservoir. This comprises a cylindrical mandrel, adapted to fit inside the cylindrical cavity within a valve body, to form a pressure seal at two locations within the valve body, so that fluid flow in the fluid flow path between the first fluid reservoir and the second fluid reservoir is permitted.

Preferably, the invention is a valve body access adapter wherein the cylindrical mandrel has a fluid flow path connecting the curved side of the cylindrical mandrel body to the circular proximal end of the cylindrical mandrel body. The circular proximal end of the cylindrical mandrel is fitted with a suitable connection of known types such as flange, hub, hammer union, threaded and the like. A fluid conduit of known types is then connected to the circular proximal end of the cylindrical mandrel to form the fluid flow path required. The fluid conduit of known types may be hose, flexible pipe, steel pipe and the like.

Preferably also, the cylindrical mandrel has seals of known types around the external circumference of the cylindrical mandrel that engage the interior of the valve body. These seals are adapted to seal within the valve body to bring the cylindrical mandrel into fluid communication with the interior of the valve body and so into fluid communication with the bore passing through the valve body.

Preferably also, the seals comprises an inner and outer set of seals adapted to seal against pressure and flow. The seals of known types may be resilient to ensure they are able to adapt to the surface of the cylindrical cavity within the valve body. The seals are also adapted to suit the pressure and temperature expected during operations.

Preferably also, the inner seals and outer seals are located on the exterior of the cylindrical mandrel body on either side of the fluid flow path that passes through the curved side of the cylindrical mandrel body.

Preferably also, the inner seals on the distal side of the cylindrical mandrel engage the interior of the cylindrical cavity of the valve body to form a circumferential seal around the cylindrical cavity located in between the bore passing through the valve body and the closed end of the cylindrical cavity within the valve body. The inner seals ensure a fluid barrier between the fluid flow path and the vent port that vents the closed end of the cylindrical cavity within the valve body.

Preferably also, the outer seals on the proximal side of the cylindrical mandrel engage the interior of the cylindrical cavity of the valve body to form a circumferential seal around the cylindrical cavity located in between the bore passing through the valve body and the open end of the cylindrical cavity that is within the valve body. The outer seals ensure a fluid barrier between the fluid flow path and the external environment outside the valve body.

Preferably also, a vent port that is not in fluid communication with the bore passing through the valve body, passes along the length of the apparatus from the distal end to the proximal end to provide fluid communication between the closed end of the cylindrical cavity within the interior of the valve body and the ambient pressure at the exterior of the valve body. The vent port ensures that no fluid pressure can build up in the closed end of the cylindrical cavity within the valve body. The vent port therefore ensures that no pressure can act on the inner seals other than the fluid pressure in the bore passing through the valve body.

With the vent port in place, the pressure acting on the inner seals and the outer seals is equal. As the diameter of the inner seals and outer seals are also equal the resultant thrust force generated by the fluid pressure over the inner seal area is equal to the thrust force generated by the fluid pressure over the outer seal area. As the thrust forces are equal along the axis of the cylindrical mandrel, the cylindrical mandrel acts in a manner that is similar to a balanced hot stab of known types.

Preferably also, a vent port that is not in fluid communication with the bore passing through the valve body, passes along the length of the apparatus from the distal end to the proximal end to provide fluid communication between the volume enclosed in between the inner seals and the closed end of the cylindrical cavity within the valve body and the ambient pressure at the exterior of the valve body.

Preferably also, a set of gripping devices of known types may be fitted to the external circumference of the apparatus being adapted to grip against the interior of the valve body to hold the apparatus within the valve body. With a vent port fitted, the use of gripping devices are not intended to resist pressure forces but are a convenient way to avoid accidental withdrawal of the cylindrical mandrel during fluid flow operations.

Preferably also, a clamp is fitted to the exterior of the apparatus so that the clamp stops against the entrance to the valve body. The location of the clamp may be arranged such that when it stops against the entrance to the valve body it acts as a visual check that the apparatus is correctly located within the cavity of the valve body ensuring the inner and outer seals are in the correct location.

Preferably also, the clamp is fitted with a handle or other device to assist the placement of the apparatus into the cavity of the valve body. The handle may be fitted with an arrangement of known types that is particularly adapted for use subsea with WROV and the like.

Preferably also, the clamp is fitted with a securing device that engages the underside of the exterior of the valve body when the apparatus is rotated around the axis of the cylindrical cavity of the valve body. The securing device is not intended to resist pressure forces but is a convenient way to avoid accidental withdrawal of the cylindrical mandrel during fluid flow operations.

In accordance with the second aspect of the invention there is provided a method wherein the method includes the initial step of removing the valve bonnet and all internal components of the valve from the cavity of the valve body and inserting the adapter into the interior of the valve body.

Preferably also, the valve bonnet may be cut off using a Diamond Wire Cutting Tool (DWCT) and the like. The option to cut off the valve bonnet is of particular value when decommissioning older facilities and in particular in the case of subsea operations where other access options are more complex.

Preferably also, the closed end of the valve body may be cut off using a DWCT and the like. With the bottom cut off the valve body there is a clear passage through the valve body perpendicular to the axis of the bore of the fluid pathway passing through the valve body. As there is no longer any risk of trapped pressure within the valve body a conventional hot stab of known types may be inserted into the cylindrical cavity of the valve body to provide a fluid flow path into the bore passing through the valve body. Where a conventional hot stab is used in this manner it is necessary to seal the device within the valve body in accordance with the first aspect of the invention.

In accordance with the third aspect of the invention there is provided a valve body adapter for connecting to a valve body, comprising a cylindrical spool adapted to attach to the top of a valve body using the same principle of attachment as used for the original valve bonnet. The option to connect to the top of the valve body is of particular value where there are no access issues and it is possible to unbolt the valve bonnet and bolt on the adapter manually. In the case of subsea this manual intervention may be done by divers and the like.

Preferably also, the cylindrical spool has a fluid flow path through the center bringing the apparatus into fluid communication with the interior of the valve body and so into fluid communication with the bore passing through the valve body.

In accordance with the fourth aspect of the invention there is provided a valve body adapter for connecting to a valve body, comprising a cylindrical stab mandrel that stops against the entrance of the valve body which is fitted with a cylindrical mandrel adapted to fit inside the cylindrical cavity within a valve body.

Preferably also, seals around the external circumference of the cylindrical stab mandrel engage the interior of the valve body to form a seal within the valve body, bringing the apparatus into fluid communication with the interior of the valve body and so into fluid communication with the bore passing through the valve body.

Preferably also, a set of gripping devices of known types are fitted to the external circumference of the cylindrical stab mandrel being adapted to grip against the interior of the valve body to hold the cylindrical stab mandrel within the valve body. In this embodiment there is no vent port fitted so the gripping devices are specifically intended to resist the pressure forces acting on the seals. In the case of decommissioning the gripping devices may be permanent where they are not intended to be released but remain in place once the fluid flow operations are complete.

In accordance with the fifth aspect of the invention there is provided an apparatus and method for connecting to a valve body wherein there is no fluid flow path within the cylindrical mandrel, adapted to fit inside the cylindrical cavity within a valve body, to form a pressure seal at two locations within the valve body, such that fluid flow outside the bore passing through the valve body is not permitted.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings.

Figure 1 illustrates a cross section of the apparatus which is a cylindrical mandrel 10 located inside the internal cylindrical cavity 11 of a conventional valve body 12. The cylindrical mandrel 10 is fitted with a set of outer seals 13 on the proximal end and a set of inner seals 14 on the distal end that both form a circumferential seal around the internal diameter of the cylindrical cavity 11 on either side of the bore 15 passing through the valve body 12.

Figure 1 also illustrates the fluid flow path 16 that passes through the cylindrical mandrel 10 from the curved side 17 of the cylindrical mandrel body to the circular proximal end 18 of the cylindrical mandrel 10. Other fluid conduits of various known types (not shown) may be connected to the opening 18 at the external circular proximal end of the cylindrical mandrel 10 as required.

Figure 1 also illustrates the clamp 19 that may be attached to the cylindrical mandrel 10 so that it stops against the entrance 30 of the valve body 12 when the inner seals 14 and outer seals 13 are correctly positioned within the cylindrical cavity 11 within the valve body 12. The clamp 19 may be fitted with a handle 23 of various known types. The handle 23 may be especially adapted to suit WROV operations subsea.

Figure 1 also illustrates the vent port 20 that provides a fluid flow path from the void space 21 of the cylindrical cavity 11 of the valve body 12 to the exterior of the cylindrical mandrel 10 through a vent port outlet 22. The vent port 20 is not in fluid communication with either the bore 15 passing through the valve body 12 or the bore 16 passing through the cylindrical mandrel 10. This vent port 20 ensures that no pressure can build up under the inner seals 14 thereby eliminating any pressure load that may eject the cylindrical mandrel 10 from the valve body 12. The vent port outlet 22 may be attached to a fluid conduit that can allow for pressure and flow monitoring of the void space 21 of the cylindrical cavity 11 of the valve body 12. The vent port outlet 22 may also be attached to a suction device that has the effect of pulling down on the inner seals 14 to hold the cylindrical mandrel 10 inside the cylindrical cavity 11 within the valve body 12.

Figure 2 illustrates an alternative arrangement where the bottom 24 of the valve body 12 has been cut off. With the bottom 24 cut off the valve body 12 there is no longer any need for the vent port 20 however the cylindrical mandrel 10 can still function as a flow path as shown. The other result of cutting off the bottom 24 of the valve body 12 is that it also allows the use of other conventional hot stabs of various known types which may also seal against the cylindrical cavity 11 within the valve body 12.

Figure 3 illustrates a cross section of another embodiment of the cylindrical mandrel 10 where the flow path 16 (as illustrated in figure 1) is removed. With the flow path removed the cylindrical mandrel 10 acts as a sealing plug where the outer seals 13 seal pressure and flow inside the valve body 12. In this embodiment the vent port 20 acts as described in figure 1 where the vent port 20 ensures that no pressure can build up under the inner seals 14 thereby eliminating any pressure load that may eject the cylindrical mandrel 10 from the valve body 12.

Figure 4 illustrates a cross section of an alternative embodiment which is a cylindrical spool 25 that connects to the top 30 of the valve body 12 where it replaces the original valve bonnet. The sealing arrangement between the cylindrical spool 25 and the top 30 of the valve body 12 is the same as used for the original valve bonnet. The securing arrangement between the cylindrical spool 25 and the top 30 of the valve body 12 is the same as used for the original valve bonnet. Other fluid conduits of various known types (not shown) may be connected to the opening 26 at the external circular end of the cylindrical spool 25 as required.

Figure 5 illustrates a cross section of an alternative embodiment which is a cylindrical stab mandrel 27 that lands on the top 30 of the valve body 12 where it replaces the original valve bonnet. The set of seals 13 form a circumferential seal around the internal diameter of the cylindrical cavity 11 within the valve body 12. The sealing arrangement between the cylindrical strab mandrel 27 and the top 30 of the valve body 12 may also be the same as used for the original valve bonnet. The set of gripping devices 28 of known types are fitted to the cylindrical stab mandrel 27 and grip the wall 29 of the cylindrical cavity 11 of the valve body 12 to secure the cylindrical stab mandrel 27 within the valve body 12. Other fluid conduits of various known types (not shown) may be connected to the opening 26 at the external circular end of the cylindrical stab mandrel 27 as required.

Figure 6 illustrates a cross section of an alternative embodiment of the cylindrical mandrel 10 (previously illustrated in figure 1) wherein a set of gripping devices 28 of known types is fitted to the cylindrical mandrel 10 and grips the wall 29 of the cylindrical cavity 11 of the valve body 12 to secure the cylindrical mandrel 10 within the valve body 12.

Figure 7 illustrates a side view of the cylindrical mandrel 10 looking along the bore 15 that passes through the valve body 12 where the handle 23 on the clamp 19 on the cylindrical mandrel 10 is fitted with a shaped arm 31 that rotates with the cylindrical mandrel 10 so that the lower section of the shaped arm 31 fits under the pipework connected to the valve body 12. With the lower section of the shaped arm 31 rotated under the pipework it is no longer possible to remove the cylindrical mandrel 10 from the valve body 12.

Figure 8 illustrates the case where the cylindrical mandrel 10 (as illustrated in figure 1) is used in a cylindrical cavity 11 of a valve body 12 that is part of an integrated valve block such as used in subsea trees on oil and gas installations.

Claims

Claims 1. A valve body access adapter for connecting to a valve body, to provide a fluid flow path, between a first fluid reservoir and a second fluid reservoir, comprising a cylindrical mandrel, adapted to fit inside the cylindrical cavity within a valve body, to form a pressure seal at two locations within the valve body, such that fluid flow in the fluid flow path between the first fluid reservoir and the second fluid reservoir is permitted.
2. Apparatus as claimed in claim 1 wherein the cylindrical mandrel has a fluid flow path connecting the curved side of the cylindrical mandrel body to the circular proximal end of the cylindrical mandrel body.
3 Apparatus as claimed in claim 1 or claim 2 wherein seals of known type around the external circumference of the cylindrical mandrel engage the interior of the valve body, the seals being adapted to seal within the valve body to bring the apparatus into fluid communication with the interior of the valve body and so into fluid communication with the bore passing through the valve body.
4. Apparatus as claimed in claim 3 wherein the seals comprises an inner and outer set of seals adapted to seal against pressure and flow.
Apparatus as claimed in claim 4 wherein the inner seals and outer seals are located on the exterior of the cylindrical mandrel body on either side of the fluid flow path that passes through the curved side of the cylindrical mandrel body.
6 Apparatus as claimed in claim 5 wherein the inner seals on the distal side of the cylindrical mandrel engage the interior of the cylindrical cavity of the valve body to form a circumferential seal around the cylindrical cavity located in between the bore passing through the valve body and the closed end of the cylindrical cavity within the valve body.
7 Apparatus as claimed in claim 5 wherein the outer seals on the proximal side of the cylindrical mandrel engage the interior of the cylindrical cavity of the valve body to form a circumferential seal around the cylindrical cavity located in between the bore passing through the valve body and the open end of the cylindrical cavity within the valve body.
8 Apparatus as claimed in any preceding claim wherein a vent port that is not in fluid communication with the bore passing through the valve body, passes along the length of the apparatus from the distal end to the proximal end to provide fluid communication between the closed end of the cylindrical cavity within the interior of the valve body and the exterior of the valve body.
9 Apparatus as claimed in any preceding claim wherein a vent port that is not in fluid communication with the bore passing through the valve body, passes along the length of the apparatus from the distal end to the proximal end to provide fluid communication between the volume enclosed in between the inner seals and the closed end of the cylindrical cavity within the valve body and the exterior of the valve body.
10. Apparatus as claimed in any preceding claim wherein there is no fluid flow path within the apparatus in fluid communication with the bore passing through the valve body.
11. Apparatus as claimed in claim 1 and claim 21 wherein a set of gripping devices of known types are fitted to the external circumference of the apparatus being adapted to grip against the interior of the valve body to hold the apparatus within the valve body.
12. Apparatus as claimed in any preceding claim wherein a clamp is fitted to the exterior of the apparatus so that the clamp stops against the entrance to the valve body when the apparatus is correctly located within the cavity of the valve body ensuring the seals are in the correct location.
13. Apparatus as claimed in claim 12 wherein the clamp is fitted with a handle or other device to assist the placement of the apparatus into the cavity of the valve body.
14. Apparatus as claimed in claim 12 wherein the clamp is fitted with a securing device that engages the underside of the exterior of the valve body when the apparatus is rotated around the axis of the cylindrical cavity of the valve body.
15. A method as claimed in claim 1 wherein the method includes the initial step of removing the valve bonnet and all internal components of the valve from the cavity of the valve body and inserting the adapter into the interior of the valve body.
16. A method as claimed in claim 15 wherein the valve bonnet is cut off using a Diamond Wire Cutting Tool (DWCT) and the like.
17. A method as claimed in claim 15 or claim 16 wherein the closed end of the valve body is cut off using a Diamond Wire Cutting Tool (DVVCT) and the like.
18. A method as claimed in claim 17 wherein a conventional hot stab of known types is inserted into the cylindrical cavity of the valve body to provide a fluid flow path into the bore passing through the valve body.
19. A valve body adapter for connecting to a valve body, comprising a cylindrical spool adapted to attach to the top of a valve body using the same principle of attachment as used for the original valve bonnet.
20. Apparatus as claimed in claim 19 wherein the cylindrical spool has a fluid flow path through the center bringing the apparatus into fluid communication with the interior of the valve body and so into fluid communication with the bore passing through the valve body.
21. A valve body adapter for connecting to a valve body, comprising a cylindrical stab mandrel that stops against the entrance of the valve body which is fitted with a cylindrical mandrel adapted to fit inside the cylindrical cavity within a valve body.
22. Apparatus as claimed in claim 21 wherein seals around the external circumference of the cylindrical stab mandrel engage the interior of the valve body to form a seal within the valve body, bringing the apparatus into fluid communication with the interior of the valve body and so into fluid communication with the bore passing through the valve body.
23. Apparatus as claimed in any of the preceding claims wherein the valve body is subsea.