AU2010226562B2

AU2010226562B2 - Locking penetrator

Info

Publication number: AU2010226562B2
Application number: AU2010226562A
Authority: AU
Inventors: Paulo Cezar Silva Paulo
Original assignee: Aker Solutions Inc
Current assignee: Aker Solutions Inc
Priority date: 2009-03-18
Filing date: 2010-03-18
Publication date: 2014-11-20
Anticipated expiration: 2030-03-18
Also published as: GB2481171A; NO346731B1; GB201117793D0; GB2481171B; AU2010226562A1; WO2010107987A1; NO20111407A1; CA2759904A1; CA2759904C

Abstract

A penetrator comprising a housing and a bulkhead positioned within the housing and configured to slide relative to the housing. The bulkhead comprises a bulkhead hydraulic coupling and a bulkhead electrical connection. The penetrator also includes a system for locking the bulkhead in a desired position relative to the housing.

Description

- 1 LOCKING PENETRATOR BACKGROUND OF THE DISCLOSURE [0001] The present disclosure claims priority to United States Provisional Application No. 61/161,143, filed on March 18, 2009, the disclosure of which is hereby incorporated by reference in its entirety. FIELD OF THE DISCLOSURE [0002] The present disclosure relates generally to penetrators employed in subsea development projects, and more specifically, to a penetrator for providing hydraulic and electric connection to subsea Christmas trees. DESCRIPTION OF THE RELATED ART [0003] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. [0004] Subsea oil and gas fields often employ subsea well equipment that is located on the seabed and tied back to a surface structure, such as a production facility and/or ship. Providing for desired control of subsea equipment can be difficult due to the extreme underwater conditions involved in the use and deployment of such equipment. [0005] In subsea Christmas tree systems, it is well known to have hydraulic and electric communication through the stack up components in order to provide control of the downhole completion valves and monitor reservoir activity. Penetrators that mate with the Christmas tree are often used to provide the desired hydraulic control and the electrical power source for operating the Christmas tree systems. Examples of hydraulic penetrators and electrical penetrators employed in Christmas trees are taught in U.S. Patent No. 6,810,954, the disclosure of which is hereby incorporated by reference in its entirety. [0006] In the past, connecting penetrators to existing Christmas tree equipment has often been performed by mechanically stroking and locking the penetrator using ROV torque operation. However, use of an ROV can be time consuming and expensive.

-2 SUMMARY OF THE INVENTION [0007] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [0008] To this end, a first aspect of the present invention provides a penetrator for association with a subsea Christmas tree and constructed to provide detachable hydraulic and electrical connections to such a Christmas tree, the penetrator comprising: a housing attachable to a Christmas tree; a bulkhead slidable within the housing and having a bulkhead hydraulic coupling and a bulkhead electrical connection arranged for mating with equivalent coupling and connector on the Christmas tree; and locking means for locking the bulkhead in a position relative to the housing with the couplings and connectors mated, wherein the locking means comprises a groove positioned in a surface of the bulkhead proximate to the housing, wherein the locking means further comprises a locking ring positioned in the housing so as to be capable of mating with the groove, and wherein the locking means further comprises one or more locking dogs and a locking sleeve configured to apply a force to the locking dogs to lock the bulkhead in the mated position. [0009] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". [0010] A second aspect of the present invention provides a subsea Christmas tree assembly for controlling production from a subsea oil or gas well, the Christmas tree assembly comprising: a hydraulic and electrical communication system for controlling a downhole completion valve and monitoring reservoir activity; a penetrator receiving assembly positioned on a Christmas tree; and a penetrator configured to connect to the penetrator receiving assembly, the penetrator comprising: a housing attachable to the Christmas tree; -3 a bulkhead positioned within the housing and having a bulkhead hydraulic coupling and a bulkhead electrical connection arranged for mating with equivalent coupling and connector on the Christmas tree; and a locking means for locking the bulkhead in a position relative to the housing with the couplings that connectors mated, wherein the locking means comprises a groove positioned in a surface of the bulkhead proximate to the housing, wherein the locking means further comprises a locking ring positioned in the housing so as to be capable of mating with the groove, and wherein the locking means further comprises one or more locking dogs and locking sleeve configured to apply a force to the locking dogs to lock the bulkhead in the mated position. [0011] A third aspect of the present invention provides a method of operating a penetrator, the method comprising: attaching a penetrator proximate to a receptacle of a Christmas tree, the penetrator comprising: a housing attachable to a Christmas tree; a bulkhead slidable within the housing and having a bulkhead hydraulic coupling and a bulkhead electrical connection arranged for mating with equivalent coupling and connector on the Christmas tree; and locking means for locking the bulkhead in a position relative to the housing with the couplings and connectors mated, wherein the locking means comprises a groove positioned in a surface of the bulkhead proximate to the housing, wherein the locking means further comprises a locking ring positioned in the housing so as to be capable of mating with the groove, and wherein the locking means further comprises one or more locking dogs and a locking sleeve configured to apply a force to the locking dogs to lock the bulkhead in the mated position. [0012] An embodiment of the present disclosure is directed to a penetrator comprising a housing. A bulkhead is positioned within the housing and configured to slide relative to the housing. The bulkhead comprises a bulkhead hydraulic coupling and a bulkhead electrical connection. The penetrator also comprises a system for locking the bulkhead in a desired position relative to the housing. [0013] The present disclosure is also directed to a subsea Christmas tree assembly for controlling production from a subsea oil or gas well. The Christmas tree assembly comprises a hydraulic and electrical communication system for controlling a downhole completion valve and -4 monitoring reservoir activity. A penetrator receiving assembly is positioned on the Christmas tree. The penetrator receiving assembly comprises a plurality of receptacles and is configured to couple a hydraulic control source and an electrical power source to the communication system. A penetrator is configured to connect to the penetrator receiving assembly. The penetrator comprises a housing. A bulkhead is positioned within the housing and configured to slide relative to the housing. The bulkhead comprises a bulkhead hydraulic coupling and a bulkhead electrical connection. The penetrator also includes a system for locking the bulkhead in a desired position relative to the housing [0014] The present disclosure is also directed to a method of operating a penetrator. The method comprises positioning a penetrator proximate to a receptacle of a Christmas tree, the penetrator comprising a housing and a bulkhead positioned at a first position within the housing. The bulkhead is moved into a second position relative to the housing, at which second position a bulkhead coupling mates with the Christmas tree receptacle. The bulkhead is locked in the second position. BRIEF DESCRIPTION OF THE DRAWINGS [0015] One or more preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: [0016] FIG. 1 illustrates a penetrator adjacent a Christmas tree, according to an embodiment of the present disclosure. [0017] FIG. 2 illustrates the penetrator of FIG. 1 connected to the Christmas tree to form a Christmas tree assembly, according to an embodiment of the present disclosure. [0018] FIG. 3 illustrates a penetrator with one portion in a position to be locked and one portion in an unlocked position, according to an embodiment of the present disclosure. [0019] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.

DETAILED DESCRIPTION [0020] FIG. 1 illustrates a penetrator 2 that can be used to connect to a penetrator receiver assembly 4 of a Christmas tree 5, according to an embodiment of the present disclosure. The penetrator 2 comprises a housing 6. A bulkhead 8 is positioned within the housing 6. The bulkhead 8 is configured to slide relative to the housing 6 in a piston-like action, so as to connect and disconnect couplings 10 with the penetrator receiver assembly 4. The penetrator 2 can include a system for locking the bulkhead 8 to the housing 6. Any suitable locking system capable of maintaining the bulkhead 8 in a desired position relative to housing 6 can be employed. One exemplary locking system includes a groove 12 in the bulkhead 8, a locking ring 14, locking dogs 16 and a locking sleeve 18. The components of the penetrator 2 will now be described in greater detail. [0021] In an embodiment, housing 6 can include a bonnet 6A that can provide the structural support for the penetrator 2. For example, bonnet 6A can be engineered to contain an increase in internal pressure of a given amount, as desired. Housing 6 can be attached to a desired position proximate a penetrator receiver assembly 4 on a Christmas tree 5 using any suitable means, such as bolts or clamping devices. The housing 6 can include a piston chamber 6B in which the bulkhead 8 can slide. Seals 6C can be positioned in any desired manner to provide a desired seal between the Christmas tree 5 and the housing 6. [0022] The bulkhead 8 comprises bulkhead hydraulic couplings and bulkhead electrical connections, together shown as couplings 10 in the embodiment of FIG. 1. The bulkhead can include additional components, such as hydraulic conduits and ports for actuating various parts of the penetrator 2. The bulkhead 8 can be configured to carry, protect and/or align the components during the mating of the couplings 10 with the penetrator receiver assembly 4. In an embodiment, a groove 12 can be positioned in a surface of the bulkhead 8 proximate the housing 6. [0023] The bulkhead 8 can be moved back and forth inside piston chamber 6B using any suitable driving mechanism. In an embodiment, hydraulics can be used to provide the force used to drive the bulkhead 8. Any suitable system of hydraulic conduits and ports in housing 6 and/or bulkhead 8 can be used to provide the hydraulics. For example, pressure can be applied through hydraulic conduit 8D to drive the bulkhead 8 from a mated position, as shown in FIG. 2, to an unmated position, as shown in FIG. 1. Hydraulic force can also be used to move the bulkhead 8 into a mated position. For example, hydraulic pressure introduced -6 through hydraulic conduit 8C can potentially be used to drive the bulkhead 8 from an unmated position to a mated position. [0024] Alternatively, other actuating means can be employed as a driving force for bulkhead 8. Examples of such actuating means can include electric motors, magnetic force or mechanical actuation of any type. [0025] In an embodiment, a locking ring 14 is positioned in the housing 6. The locking ring 14 is configured to retain the bulkhead 8 in its mating position against any spring back force when the locking sleeve 18 is moved to mechanically lock the system, as will be discussed in greater detail below. As the bulkhead 8 slides relative to the housing 6, the locking ring 14 can be moved between an unmated position outside of the groove 12, as shown in FIG. 1; and a mated position inside of the groove 12, as shown in FIG. 2. When in the mated position, the locking ring 14 latches with the groove 12, thereby fixing the bulkhead 8 in a mated position relative to the housing 6. [0026] One or more locking dogs 16 can be positioned proximate the locking ring 14. Locking dogs 16 can provide the physical load path to constrain the locking ring 14 to keep the bulkhead from moving relative to the housing 6. [0027] The locking sleeve 18 can be a piston responsible to provide the rigid mechanical lock of the system. The locking sleeve 18 can be configured to slide back and forth between the unlocked position, shown in the bottom half of FIG. 2, and the locked position, shown in the top half of FIG. 2. While the locking sleeve 18 is shown in both the unlocked and locked position for illustrative purposes in FIG. 2, it is to be understood that the locking sleeve 18 can be either a single integral component or a multi-part component. [0028] In an embodiment, the locking sleeve 18 can be hydraulically moved over the locking dogs 16, compressing them downward against the locking ring 14. For example, a hydraulic conduit 8C can provide the force to move locking sleeve 18 from the locked position to the unlocked position; and a hydraulic conduit 28 can provide the force to move locking sleeve 18 from the unlocked position to the locked position. The hydraulic conduits may also potentially be used for fluid displacement from the penetrator 2. For example, hydraulic conduit 28 can potentially be employed to allow fluids to exit the space 22 when locking sleeve 18 is forced into the unlocked position. In embodiments, other means of actuation can be employed to drive the locking sleeve 18, such as electric motors, magnetic force or any suitable mechanical -7 actuation. When in the locked position, the locking sleeve 18 applies a force to the locking dogs 16 to lock the bulkhead 8 in the mated position. [0029] In an embodiment, the penetrator 2 also comprises a sleeve keeper 20 adjacent to the locking sleeve 18. As shown in FIGS. 1 and 2, the sleeve keeper 20 can be configured to allow the locking sleeve 18 to slide back and forth in a space 22 formed between the sleeve keeper 20 and the bulkhead 8. [0030] In an embodiment, the systems of the present disclosure can include an emergency disconnection system that can be used to move the bulkhead from a mated position to an unmated position in the event that a malfunction occurs in the normal disconnection mode. For example, the sleeve keeper 20 and locking sleeve 18 can be configured to rotate relative to the bulkhead 8 to allow emergency release of the locking dogs 16 from the locking sleeve 18. In an embodiment, the location of the conduit 28 (FIG. 2) can potentially allow the hydraulic connection (not shown) to the conduit 28 to be cut prior to rotating sleeve keeper 20, if necessary, in order to release pressure on sleeve keeper 20 and locking sleeve 18. [0031] As shown in the embodiment of FIG. 3, the locking sleeve 18 can include an unlock profile 24 that can be positioned over the locking dogs 16 by the rotation of the sleeve keeper 20 and locking sleeve 18 in order to provide clearance for the locking dogs 16 and allow the locking ring 14 to move out of the groove 12 and into an unmated position. The degree of rotation of the sleeve keeper 20 and the locking sleeve 18 for providing the desired release can be any suitable amount, such as, for example, 60 degrees, 90 degrees or 180 degrees. In an embodiment, a release lever 26 attached to the sleeve keeper 20 can be used to apply a force sufficient to rotate the sleeve keeper 20 and locking sleeve 18. Any suitable alternative means that can provide the desired rotation can be used in place of release lever 26. The force applied to rotate the sleeve keeper 20 can be transferred to the locking sleeve by any desired means, including well known means, such as, for example, a slot and keyway arrangement (not shown). [0032] FIG. 3 illustrates the penetrator 2 with a portion 8A of the bulkhead 8 in a position to be locked, but with the locking ring 14 and locking dogs 16 in a released position by the rotation of sleeve keeper 20 and locking sleeve 18. At this point, a hydraulic actuation means can be employed to force bulkhead 8 into an unlocked position and thereby uncouple the couplings 10 from the penetrator receiver assembly 4. A lower portion 8B of the bulkhead 8 illustrates the bulkhead 8 in the resulting unlocked position.

-8 [0033] The hydraulic actuation means can be any suitable means, such as, for example, hydraulic pressure applied via conduits 8C and 8D. Alternatively, pressure can be applied inside the piston chamber 6B so as to expel the bulkhead 8 away from the Christmas tree 5 and uncouple the couplings 10. Any suitable means can be employed to apply pressure inside the pressure chamber 6B, such as by a port constrained by a burst disc (not shown) that can be burst when it is time to expel the bulkhead 8. [0034] As shown in FIG. 3, when bulkhead 8 is forced into the mated position, couplers 10 move forward relative to the housing 6. FIG. 2 illustrates bulkhead 8 in a mated position, with the couplers 10 pushed forward in housing 6 so as to connect with receptacles 32, thereby providing the desired connection between the hydraulic and electrical communication system 34 of the Christmas tree 5 and the bulkhead hydraulic couplings and bulkhead electrical connections 10 of the penetrator 2. Thus, when the bulkhead 8 is in the mated position, the penetrator 2 can provide the hydraulic and electrical connections to a hydraulic control source and/or an electrical power source (not shown) that can be used for controlling production from the subsea Christmas tree 5. For example, hydraulic and electrical communications via the penetrator 2 can be employed for controlling a downhole completion valve (not shown) and/or for monitoring reservoir activity. When bulkhead 8 is in an unmated position, as shown in FIG. 1, the couplers 10 are pushed back in housing 6 so as not to connect with receptacles 32, thereby disconnecting the subsea Christmas tree 5 from the hydraulic and electrical connections provided by the penetrator 2. [0035] In an exemplary process of operating the penetrator 2, the penetrator 2 can be moved into position proximate the Christmas tree 5 so as to be aligned with the receptacles 32 in the penetrator receiver assembly 4, as shown in FIG. 1. The housing 6 can be attached to the Christmas tree 5 with bolts or other means, if desired. The bulkhead 8 can then be moved relative to the housing 6 until the couplings 10 mate with the receptacles 32 of the penetrator receiver assembly 4, as shown in FIG. 2. The bulkhead 8 can then be locked in a desired position relative to the housing using any desired locking means. The locking can be carried out by, for example, using the locking ring 14 and the groove 12, as described herein, to fix the bulkhead in position relative to the housing 6. The locking sleeve 18 can then be positioned so as to apply force to the one or more locking dogs 16 proximate the locking ring and thereby lock the bulkhead in the mated position. [0036] If it is desired to disconnect the penetrator 2 from the Christmas tree 5, the locking sleeve 18 can be repositioned to release the locking dogs 16 and locking ring 14. This can -9 occur by any suitable means, such as applying hydraulic pressure through a hydraulic conduit 8C or by other means disclosed herein. Alternatively, if the locking sleeve 18 cannot be repositioned using hydraulic pressure, force can be applied to release lever 26 to rotate sleeve keeper 20 and locking sleeve 18 until the unlock profile 24 aligns to release the locking dogs 16 and locking ring 14, as discussed above. Any suitable means, such as the hydraulic or other means disclosed herein, can then be used to provide a force sufficient to move the bulkhead 8. into an unmated position. [0037] Although various embodiments have been shown and described, the present disclosure is not so limited and will be understood to include all such modifications and variations as would be apparent to one skilled in the art.

Claims

1. A penetrator for association with a subsea Christmas tree and constructed to provide detachable hydraulic and electrical connections to such a Christmas tree, the penetrator comprising: a housing attachable to a Christmas tree; a bulkhead slidable within the housing and having a bulkhead hydraulic coupling and a bulkhead electrical connection arranged for mating with equivalent coupling and connector on the Christmas tree; and locking means for locking the bulkhead in a position relative to the housing with the couplings and connectors mated, wherein the locking means comprises a groove positioned in a surface of the bulkhead proximate to the housing, wherein the locking means further comprises a locking ring positioned in the housing so as to be capable of mating with the groove, and wherein the locking means further comprises one or more locking dogs and a locking sleeve configured to apply a force to the locking dogs to lock the bulkhead in the mated position.

2. The penetrator of claim 1, further comprising a sleeve keeper adjacent to the locking sleeve, the sleeve keeper being configured to allow emergency release of the locking means.

3. The penetrator of claim 2, wherein the sleeve keeper is configured to rotate the locking sleeve relative to the bulkhead to release the locking dogs and the locking sleeve.

4. The penetrator of claim 3, further comprising a release lever attached to the sleeve keeper.

5. The penetrator of claim 1, wherein the penetrator is configured to hydraulically move the bulkhead between a mated position and an unmated position.

6. A subsea Christmas tree assembly for controlling production from a subsea oil or gas well, the Christmas tree assembly comprising: a hydraulic and electrical communication system for controlling a downhole completion valve and monitoring reservoir activity; a penetrator receiving assembly positioned on a Christmas tree; and a penetrator configured to connect to the penetrator receiving assembly, the penetrator comprising: - 11 a housing attachable to the Christmas tree; a bulkhead positioned within the housing and having a bulkhead hydraulic coupling and a bulkhead electrical connection arranged for mating with equivalent coupling and connector on the Christmas tree; and a locking means for locking the bulkhead in a position relative to the housing with the couplings that connectors mated, wherein the locking means comprises a groove positioned in a surface of the bulkhead proximate to the housing, wherein the locking means further comprises a locking ring positioned in the housing so as to be capable of mating with the groove, and wherein the locking means further comprises one or more locking dogs and locking sleeve configured to apply a force to the locking dogs to lock the bulkhead in the mated position.

7. The subsea Christmas tree assembly of claim 6, further comprising a sleeve keeper adjacent to the locking sleeve, the sleeve keeper being configured to allow emergency release of the locking means.

8. The subsea Christmas tree assembly of claim 7, wherein the sleeve keeper is configured to rotate the locking sleeve relative to the bulkhead to release the locking dogs and the locking sleeve.

9. The subsea Christmas tree assembly of claim 8, further comprising a release lever attached to the sleeve keeper.

10. The subsea Christmas tree assembly of claim 6, wherein the penetrator is configured to hydraulically move the bulkhead between a mated position and an unmated position.

11. A method of operating a penetrator, the method comprising: attaching a penetrator proximate to a receptacle of a Christmas tree, the penetrator comprising: a housing attachable to a Christmas tree; a bulkhead slidable within the housing and having a bulkhead hydraulic coupling and a bulkhead electrical connection arranged for mating with equivalent coupling and connector on the Christmas tree; and locking means for locking the bulkhead in a position relative to the housing with the couplings and connectors mated, wherein the locking means comprises a groove positioned in a surface of the bulkhead proximate to the housing, wherein the locking means further -12 comprises a locking ring positioned in the housing so as to be capable of mating with the groove, and wherein the locking means further comprises one or more locking dogs and a locking sleeve configured to apply a force to the locking dogs to lock the bulkhead in the mated position.

12. The method of claim 11, further comprising: positioning the locking ring in the groove; and positioning the locking sleeve so as to apply force to the one or more locking dogs .

13. The method of claim 12, further comprising moving the bulkhead and locking the bulkhead by hydraulic actuation.