PLUG RETRIEVAL AND DEBRIS REMOVAL TOOL
An apparatus adapted for removing a plug (12) from a subsea Christmas tree (10) is disclosed which includes a housing (84), a distal end of the apparatus that is adapted to engage the plug (12) and a fluid passage (83) formed in the housing (84) for use in directing a stream of fluid toward the plug (12) to remove debris (90) from above the plug (12). Also disclosed is a method for removing debris (90) from a subsea Christmas tree (10) including connecting a marine riser and a blowout preventer (BOP) (60) to a subsea Christmas tree (10), lowering a plug removal tool (80) through the marine riser to the Christmas tree (10), the plug removal tool (80) having a fluid passage (83) formed therein, and forcing a fluid down the marine riser and through the fluid passage (83) in the plug removal tool (80) to wash out debris (90) in the Christmas tree (10).
1. Field of the Invention
The present invention is generally related to the field of subsea wells and tools, and more particularly, to methods and tools for retrieving wire line plugs from subsea wells, which allows debris to be removed from on top of the plugs and riser hydrostatic pressure effects to be overcome.
2. Description of the Related Art
A horizontal Christmas tree is a device that is commonly employed on many subsea wells. Such horizontal trees utilize wire line plugs. All suppliers of this type of tree have problems with debris accumulating on the plugs. A solution, which allowed the plugs to be pulled without preliminary debris clearing, and or under conditions where riser hydrostatic pressure is greater than wellhead pressure would be a significant completive advantage.
Debris from drilling and the completion riser systems accumulate on top of horizontal Christmas trees settling in the upper bore of the tubing hanger over the wire line plugs. The wire line plugs must be removed to allow access to the well bore. Removal of the debris is costly with current methods and increases in cost with water depth and rig rates, both of which are increasing. Furthermore, in deep water applications, the hydrostatic pressure in the completion riser is sometimes in excess of the wellhead pressure. This produces a downward load on the load on the wireline plug which can be larger than the wire tensile capacity. This prevents or complicates plug retrieval.
When clearing out debris from the wellhead or Christmas tree, the normal practice is to run a wire line bailer or pump to remove the debris. It is also possible to run coiled tubing into the well to wash out the debris before the wire line operations are performed. The use of coiled tubing allows a higher pulling load to be applied to the plug overcoming some of the riser-wellhead pressure balance problems. Special pulling tools may also be used to the same effect.
The current practice is an incomplete solution to the problem because the bailing tool must be run to establish if debris is present above the plug. It is then run repeatedly, which removes a limited amount of debris with each trip of the tool from the surface to the top of the debris, until it fails to retrieve debris, which indicates clearance. All of these trips cost additional time and money if the clearance can be accomplished without a separate wire line operation. Coiled tubing can be run into the well through the production riser to wash the debris from above the top of the plugs. This is considered to be a prohibitively expensive procedure due to extra equipment mobilization and the complexity of the operation. Special pulling tools, like the normal wireline pulling tools, cannot be used until the debris has been removed by separate operations.
The present invention is directed to an apparatus and methods for solving, or at least reducing the effects of, some or all of the aforementioned problems.
SUMMARY OF THE INVENTIONThe following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
In one illustrative embodiment, an apparatus adapted for removing a plug from a subsea Christmas tree is disclosed which comprises a housing, a distal end of the apparatus that is adapted to engage the plug, and a fluid passage formed in the housing that is adapted for use in directing a stream of fluid toward the plug to remove debris from above the plug.
In another illustrative embodiment, an apparatus adapted for removing a plug from a subsea Christmas tree is disclosed which comprises a housing, a distal end of the apparatus that is adapted to engage the plug, a fluid passage formed in the housing, the exit of which defines a nozzle that is adapted for use in directing a stream of fluid toward the plug to remove debris from above the plug, and a tubing hanger running tool having a bore formed therein, wherein the housing is moveably positioned within the bore.
In yet another illustrative embodiment, the invention consists of a wire line plug pulling tool with a fluid path which begins above an enlarged outside diameter section and exits at or close to the end of the tool which engages the wire line plug. The tool's enlarged outer section interacts with a reduced internal bore of the completion riser assembly, which creates a fluid flow restriction past the outside of the tool. This restriction forces any fluid pumped down the production riser through the fluid path of the tool exiting at high velocity at the end of the tool, thereby washing debris away from the pulling tool and plug interface. Furthermore, fluid pressure applied by this restriction creates a net upward or pulling load on the tool when the central wash port is closed.
No known method or tool combines the ability to remove debris from the tool-plug interface with the tool that is used to pull the plug and/or produce a net upward or pulling load on the tool using pressure from the surface.
In one illustrative embodiment, a method for removing debris from a subsea Christmas tree is disclosed which comprises connecting a marine riser and a blowout preventer (BOP) to a subsea Christmas tree, lowering a plug removal tool through the marine riser to the Christmas tree, the plug removal tool having a fluid passage formed therein, and forcing a fluid down the marine riser and through the fluid passage in the plug removal tool to wash out debris in the Christmas tree.
The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTIONIllustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present invention will now be described with reference to the attached figures. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
It should be apparent to those skilled in the art that changes can be made without departing from the scope of the invention. For example, a variety of tubing hanger running tools may be employed.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.
Claims
1. An apparatus adapted for removing a plug (12) from a subsea Christmas tree (10), comprising:
- a housing (84);
- a distal end of said apparatus that is adapted to engage said plug (12); and
- a fluid passage (83) formed in said housing (84) that is adapted for use in directing a stream of fluid toward said plug (12) to remove debris from above said plug (12).
2. The apparatus of claim 1, further comprising a tubing hanger running tool (70) having a bore (75) formed therein, wherein said housing (84) is moveably positioned within said bore (75).
3. The apparatus of claim 2, wherein said housing (84) sealingly engages said bore (75).
4. The apparatus of claim 2, wherein a seal is established between said housing (84) and said bore (75).
5. The apparatus of claim 2, wherein said tubing hanger running tool (70) further comprises a flow port (77) formed therein that defines a portion of a fluid flow passage that is adapted for removing said fluid introduced through said fluid passage (83) in said housing (84).
6. The apparatus of claim 5, wherein said flow port (77) in said tubing hanger running tool (70) is adapted to engage an external choke and kill line (62).
7. The apparatus of claim 1, wherein said apparatus further comprises a proximal end that is adapted to be coupled to a wireline device.
8. The apparatus of claim 1, wherein a distal end of said fluid passage defines a nozzle.
9. An apparatus adapted for removing a plug (12) from a subsea Christmas tree (10), comprising:
- a housing (84);
- a distal end of said apparatus that is adapted to engage said plug (12);
- a fluid passage (83) formed in said housing (84), the exit of which defines a nozzle that is adapted for use in directing a stream of fluid toward said plug (12) to remove debris from above said plug (12); and
- a tubing hanger running tool (70) having a bore (75) formed therein, wherein said housing (84) is moveably positioned within said bore (75).
10. The apparatus of claim 9, wherein said housing (84) sealingly engages said bore (75).
11. The apparatus of claim 9, wherein a seal is established between said housing (84) and said bore (75).
12. The apparatus of claim 9, wherein said tubing hanger running tool (70) further comprises a flow port (77) formed therein that defines a portion of a fluid flow passage that is adapted for removing said fluid introduced through said fluid passage (83) in said housing (84).
13. The apparatus of claim 12, wherein said flow port (77) in said tubing hanger running tool (70) is adapted to engage an external choke and kill line (62).
14. The apparatus of claim 9, wherein said apparatus further comprises a proximal end that is adapted to be coupled to a wireline device.
15. An apparatus for removing a plug (12) from a subsea Christmas tree (10), comprising:
- a tool housing (84) having a central passage (83) formed therethrough and a plug engaging means (86), said plug engaging means comprising a constricted nozzle adapted for washing out debris from above the plug (12); and
- a tubing hanger running tool (70).
16. The apparatus of claim 15, wherein said tubing hanger running tool (70) comprises a central passage (75), the tool housing (84) being movable but sealingly engaged within the passage (75).
17. The apparatus of claim 16, wherein said tubing hanger running tool (70) includes a shoulder (74).
18. The apparatus of claim 15, wherein said tubing hanger running tool (70) includes at least one flow port (77).
19. The apparatus of claim 18, wherein said apparatus includes a passage (73) connecting the flow port (77) with an external choke and kill line (62).
20. A method for removing debris (90) from a subsea Christmas tree (10), comprising:
- connecting a marine riser and a blowout preventer (BOP) (60) to said subsea Christmas tree (10);
- lowering a plug removal tool (80) through the marine riser to the Christmas tree (10), said plug removal tool (80) having a fluid passage (83) formed therein; and
- forcing a fluid down the marine riser and through said fluid passage (83) in said plug removal tool (80) to wash out debris (90) in said Christmas tree (10).
21. The method of claim 20, further comprising lowering a tubing hanger running tool (70) through the marine riser to the Christmas tree (10).
22. The method of claim 21, wherein said tubing hanger running tool (70) and said plug removal tool (80) are lowered at the same time.
23. The method of claim 21, wherein said tubing hanger running tool (70) and said plug removal tool (80) are lowered at different times.
24. The method of claim 21, wherein said tubing hanger running tool (70) comprises a flow port (77) formed therein, and wherein the method further comprises forcing said fluid through said flow port (77) in said tubing hanger running tool (70).
25. The method of claim 24, further comprising forcing fluid through a choke and kill line (62) of said Christmas tree (10).
26. A method for removing debris (90) from a subsea Christmas tree (10), comprising:
- connecting a marine riser and a blowout preventer (BOP) (60) to said subsea Christmas tree (10);
- lowering a running tool (70) through the marine riser to the Christmas tree (10);
- lowering a plug removal tool (80) towards engagement with the running tool (70); and
- forcing fluid down the riser, the fluid flowing through a passage (83) in the plug removal tool (80) to wash out debris (90) in the Christmas tree (10).
27. The method of claim 26, wherein the plug removal tool (80) is lowered together with the running tool (70).
Type: Application
Filed: Dec 8, 2006
Publication Date: Sep 24, 2009
Inventor: John E. Lawson (Todmorden)
Application Number: 12/093,387
International Classification: E21B 23/00 (20060101); E21B 23/04 (20060101);