FLANGE OVERSHOT RETRIEVAL TOOL
A tool for removing a first flange from a second flange comprises a housing having a central axis, a first end, and an open second end opposite the first end. The housing also includes a first access port extending radially therethrough. In addition, the tool comprises an annular basket grapple coaxially disposed within the second end of the housing and configured to coaxially receive and engage a first flange. The basket grapple has a first end, a second end opposite the first end, and a cutout extending radially therethrough. The outer surface of the basket grapple includes external threads that engage mating internal threads on the inner surface of the housing. Further, the tool comprises a key releasably coupled to the housing. The key is configured to selectively prevent relative rotation between the basket grapple and the housing.
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This application claims benefit of U.S. provisional patent application Ser. No. 61/478,667 filed Apr. 25, 2011, and entitled “Flange Overshot Retrieval Tool,” which is hereby incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot applicable.
BACKGROUND1. Field of the Invention
The invention relates generally to remedial devices and methods for hydrocarbon drilling and production operations. More particularly, the invention relates to devices and methods for removing a flange subsea.
2. Background of the Technology
In hydrocarbon drilling and production operations, it is common to have tubulars or pipes coupled together with mating flanges to form a flange joint. During maintenance and/or remedial operations, it may be necessary to separate the connected flanges to access passages or bores in the equipment, to advance other tools or devices through the equipment, to break down or remove the equipment, or to prepare one flange for connection to a different piece of equipment. For example, in the event of a subsea blowout, it may be necessary to separate a flanged connection between a riser and a riser flex joint so that a different piece of equipment can then be connected to the riser flex joint.
On land, such remedial operations may be relatively easy if the flange connection can be directly accessed and engaged at the surface with impact wrenches, tongs, or other suitable separation equipment. However, if the flange connection is remote from the associated surface operations (e.g., disposed downhole or subsea), it may be more difficult to sufficiently grasp and remove one flange of a flange connection from its mating flange.
Accordingly, there remains a need in the art for devices and methods to separate and remove a flange of a flange joint from its mating flange. Such devices and methods would be particularly well-received if they were suitable for remote, subsea remedial operations.
BRIEF SUMMARY OF THE DISCLOSUREThese and other needs in the art are addressed in one embodiment by a tool for removing a first flange from a second flange. In an embodiment, the tool comprises a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface. The housing also includes a first access port extending radially from the outer surface to the inner surface. In addition, the tool comprises an annular basket grapple coaxially disposed within the second end of the housing and configured to coaxially receive and engage a first flange. The basket grapple has a first end, a second end opposite the first end, a radially inner surface, a radially outer surface, and a cutout extending radially through the basket grapple from the outer surface to the inner surface. The outer surface of the basket grapple includes external threads that engage mating internal threads on the inner surface of the housing. Further, the tool comprises a key releasably coupled to the housing. The key has a first position extending radially through the access port and the cutout, and a second position removed from the cutout. The key is configured to prevent relative rotation between the basket grapple and the housing in the first position and allow relative rotation between the basket grapple and the housing in the second position.
These and other needs in the art are addressed in another embodiment by a method for removing a first flange of a subsea flange joint from a second flange of the subsea flange joint. In an embodiment, the method comprises (a) positioning a flange overshot retrieval tool over the subsea flange joint. The tool comprises a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface. The tool also comprises an annular basket grapple coaxially threaded into the second end of the housing. The basket grapple has a first end, and a second end opposite the first end. In addition, the method comprises (b) receiving the first flange into the basket grapple. Further, the method comprises (c) radially expanding the basket grapple during (b). Still further, the method comprises (d) removing the first flange from the flange joint after (b).
These and other needs in the art are addressed in another embodiment by a method. In an embodiment, the method comprises (a) lowering a flange overshot retrieval tool to a subsea flange joint including a first flange coupled to a second flange. The tool also comprises an annular basket grapple coaxially disposed in the second end of the housing. The basket grapple has a first end, and a second end opposite the first end. In addition, the method comprises (b) lowering the tool onto the first flange. Further, the method comprises (c) capturing the first flange with the basket grapple during (b). Still further, the method comprises releasing the first flange from the basket grapple subsea after (c).
Thus, embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings.
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.
Referring now to
Referring still to
Upper sub-housing 120 has a first or upper end 120a, a second or lower end 120b, a radially inner cylindrical surface 121, and a radially outer cylindrical surface 122. Upper end 120a comprises an annular flange 123 extending radially inward from surface 121, and lower end 120b comprises an annular flange 124 extending radially outward from outer surface 122. Upper flange 123 defines an annular shoulder 123a along inner surface 121 at upper end 120a, and lower flange 124 defines an annular shoulder 124a along outer surface 122 at lower end 120b. In addition, sub-housing 120 includes a plurality of circumferentially spaced through holes or apertures 126 axially positioned between flanges 123, 124. Each aperture 126 has a longitudinal axis 126a and extends radially through sub-housing 120 from inner surface 121 to outer surface 122. In this embodiment, apertures 126 are generally rectangular and oriented with axes 126a parallel to axes 105, 115. As will be described in more detail below, apertures 126 allow fluid to flow radially through sub-housing 120. Thus, for example, fluid within sub-housing 120 may flow through apertures 126 to the region outside sub-housing 120 and tool 100.
Referring still to
In this embodiment, plate 150 includes a central through bore 154 coaxially aligned with axes 105, 115 and a plurality of circumferentially spaced through bores 155 disposed about bore 154. Each bore 154, 155 extends axially through plate 150 from upper surface 151 to lower surface 152. Connection sub 140 extends coaxially through central bore 154. As will be described in more detail below, radially outer bores 155 allow fluid to flow axially through plate 150. Thus, for example, fluid within sub-housing 120 may flow axially through bores 155 to the region outside sub-housing 120 and tool 100.
As best shown in
Sub 140 is disposed within bore 154 and is rigidly attached to plate 150 (e.g., sub 140 may be welded to plate 150). In particular, sub 140 is fixed to plate 150 such that sub 140 does not move translationally or rotationally relative to plate 150.
Referring again to
Inner surface 131 includes an upper cylindrical portion 131a extending axially from upper flange 133 and a lower threaded portion 131b extending axially from lower end 130b. As seen more clearly in
Lower sub-housing 130 is disposed about upper sub-housing 120. In particular, flange 133 of lower sub-housing 130 engages outer surface 122 of upper sub-housing 120, and flange 124 of upper sub-housing 120 engages cylindrical portion 131b of inner surface 131. Further, shoulders 124, 133a axially abut. Lower sub housing 130 is attached to upper sub-housing 120 (e.g., sub-housing 130 may be welded to sub-housing 120). In particular, sub-housing 130 is fixed to sub-housing 120 such that sub-housing 130 does not move translationally or rotationally relative to sub-housing 120.
In this embodiment, an annular weight 170 is coupled to lower sub-housing 130. Specifically, weight 170 is disposed about sub-housing 130 and includes a radially inner annular shoulder 171 that axially abuts and engages upper end 130a.
Referring again to
Each foot 180 may be described as having a first or upper portion 183 extending between upper end 180a and finger 181 and a second or lower portion 184 extending between finger 181 and lower end 180b. Upper portion 183 of each foot 180 extends axially along outer surface 132 of lower sub-housing 130, and lower portion 184 of each foot 180 extends axially downward and radially outward from lower end 130b. As a result, lower portion of each foot 180 has a radially inner surface 185 that tapers axially downward and radially outward relative to sub-housing 130 and axes 105, 115. In particular, surface 185 of each foot 180 is oriented at an angle α measured from axes 105, 115 to surface 185 in side view (
As best shown in
Referring now to
As best shown in
Referring now to
Referring still to
As best shown in
Referring now to
Cutout 169 extends axially from upper end 160a, is circumferentially aligned with access port 138, and slidingly receives key 193 previously described. By positively engaging cutout 169, key 193 restricts and/or prevents basket grapple 160 from rotating relative to lower sub-housing 130 about axes 105, 115. However, when key 193 is radially withdrawn from cutout 169, basket grapple 160 is allowed to rotate relative to housing 110 about axes 105, 115. As best shown in
In general, the components of tool 100 (e.g., sub-housings 120, 130, connection sub 140, plate 150, basket grapple 160, etc.) may comprise any suitable material(s). These components preferably comprise strong, durable materials suitable for subsea use such as stainless steel.
Referring now to
During a “kick” or surge of formation fluid pressure in wellbore 301, one or more rams of BOP 320 and/or LMRP 340 are normally actuated to seal in wellbore 301 and protect personnel and hardware upstream of BOP 320 and LMRP 340. However, in some cases, BOP 320 and/or LMRP 340 may not contain wellbore 301, which may result in the discharge of such hydrocarbon fluids subsea. The emitted hydrocarbons fluids form a subsea hydrocarbon plume 360.
For subsea deployment and operation, one or more remote operated vehicles (ROVs) are preferably employed to position and monitor tool 100. In this embodiment, three ROVs 350 are employed to position and monitor tool 100. Each ROV 350 includes an arm 351 having a claw 352, a subsea camera 353 for viewing the subsea operations (e.g., the relative positions of tool 100 and joint 200, the positions and movement of arms 350 and claws 352, etc.), and an umbilical 354. Streaming video and/or images from cameras 353 are communicated to the surface or other remote location via umbilical 354 for viewing on a live or periodic basis. Arms 351 and claws 352 are controlled via commands sent from the surface or other remote location to ROV 350 through umbilical 354.
Referring first to
Moving now to
Next, referring to
As tool 100 is set down onto flange 201, feet 180, and in particular guide surfaces 185, help to guide and funnel upper flange 201 into lower end 110b of housing 110 and basket grapple 160. This may be particularly beneficial in cases where housing 110 is not perfectly coaxially aligned with joint 200 as tool 100 is lowered over upper flange 201. As tool 100 is positioned over joint 200 and lowered onto upper flange 201, apertures 126 in upper sub-housing 120 and bores 155 in plate 150 allow hydrocarbon fluids flowing from joint 200 to flow unrestricted through tool 100, thereby relieving well pressure and offering the potential to reduce the resistance to the coupling of tool 100 to flange 201. In addition, providing sufficient flow through area within tool 100 offers the potential to reduce the likelihood of hydrate formation within tool 100 and enhance visibility of tool 100. Although embodiments of tool 100 and the methods of using same described herein offer the potential to reduce hydrate formations and enhance visibility when employed to remove flange 201 from flange joint 200 that is emitting hydrocarbons, it should be appreciated that embodiments described herein may also be employed to remove a flange from a flange joint that is not emitting hydrocarbons.
As best shown in
Referring now to
In some cases, tool 100 may not be able to remove upper flange 201 subsea once it is seated within basket grapple 160 and an axial lifting force is applied to housing 110. For example, upper flange 201 may be firmly seized or corroded onto lower flange 202. In such cases, it is generally desirable to remove tool 100 from upper flange 201 so that another tool or procedure may be employed to remove flange 201. Accordingly, in this embodiment, several options are provided to remove tool 100 from upper flange 201 once it has been seated within basket grapple 160.
Referring now to
Referring now to
As previously described, circumferentially spaced shoulders 182 defined by fingers 181 function to retain basket grapple 160 within sub-housing 130. Accordingly, guide feet 180 are also removed from sub-housing 130 to allow housing 110 to be completely unthreaded from basket grapple 160. ROVs 350 remove guide feet 180 by unthreading bolts 187 via rotation of corresponding T-handles 188.
Once key 193 is removed from cutout 169 and guide feet 180 have been removed from sub-housing 130, housing 110 is simultaneously moved axially downward relative to basket grapple 160 by string 370 or under its own weight, and rotated from the surface with string 370. As sub-housing 130 moves axially downward relative to basket grapple 160, surfaces 135b, 164b move together and surfaces 135a, 164a move apart, thereby removing the camming forces applied to fingers 168c by surfaces 135a and creating radial clearance between surfaces 135a, 164b. Since basket grapple 160 is secured to upper flange 201 via engagement of teeth 167a and flange 201, housing 110 is allowed to rotate relative to basket grapple 160. As a result, housing 110 is unthreaded and backed off basket grapple 160 and may be removed to the surface leaving basket grapple 160 behind. With housing 110 removed from basket grapple 160 and upper flange 201, basket grapple 160 can be directly accessed by ROVs 350 and removed from upper flange 201 (e.g., by cutting basket grapple 160 off flange 201).
Referring now to
To access basket grapple 160 within housing 110 to create the second cut in basket grapple 160, ROVs 350 withdraw key 193 from cutout 169 by first unthreading bolts 187 coupling door 190 to lower sub-housing 130 via rotation of corresponding T-handles 188, and then pulling door 190 and key 193 from sub-housing 130 with handle 192. With key 193 removed from cutout 169, housing 110 is simultaneously moved axially downward relative to basket grapple 160 by string 370 or under its own weight, and rotated about 180° with string 370. Since basket grapple 160 is secured to upper flange 201 via engagement of teeth 167a and flange 201, housing 110 is allowed to rotate relative to basket grapple 160, thereby rotating a slot 168 that is positioned about 180° from cutout 169 and ends 160c, d into circumferential alignment with access port 138. Next, ROVs 350 access the slot 168 through port 135 and cut basket grapple 160 axially from upper end 160a to that slot 168, thereby dividing basket grapple 160 into two separate pieces, each extending about 180° about axes 105, 115. Next, housing 110 is slowly lifted axially upward with string 370. Since basket grapple 160 is cut into multiple pieces, it is loosely disposed about flange 201 and teeth 167a are not biased into positive engagement with flange 201. As a result, basket grapple 160 is lifted upward along with housing 110 from flange 201.
Referring now to
With feet 180 removed from housing 110, an axial lifting force is applied to housing 110 with string 140. Initially, the upward movement of housing 110 relative to basket grapple 160 cams fingers 168c radially inward, thereby causing teeth 167 to bite into flange 201. In general, the camming force applied to fingers 168c increases as the lifting force is increased. However, due to the relatively small radial overlap of threads 134, 163, at a sufficient lifting force, threads 134, 163 will plastically deform, thereby allowing housing 110 to be forcefully lifted from basket grapple 160. With housing 110 removed from basket grapple 160 and upper flange 201, basket grapple 160 can be directly accessed by ROVs 350 and removed from upper flange 201 (e.g., by cutting basket grapple 160 off flange 201).
Although tool 100 has been shown and described as being deployed on string 370, tool 100 may also be deployed on wireline or cable. However, it should be appreciated that wireline deployment may limit the ability to rotate housing 110 subsea, and thus, the options for releasing basket grapple 160 subsea that require rotation of housing 110 may not be available.
While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.
Claims
1. A tool for removing a first flange from a second flange, the tool comprising:
- a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface, wherein the housing includes a first access port extending radially from the outer surface to the inner surface;
- an annular basket grapple coaxially disposed within the second end of the housing and configured to coaxially receive and engage a first flange, wherein the basket grapple has a first end, a second end opposite the first end, a radially inner surface, a radially outer surface, and a cutout extending radially through the basket grapple from the outer surface to the inner surface;
- wherein the outer surface of the basket grapple includes external threads that engage mating internal threads on the inner surface of the housing; and
- a key releasably coupled to the housing, wherein the key has a first position extending radially through the first access port and the cutout, and a second position removed from the cutout, wherein the key is configured to prevent relative rotation between the basket grapple and the housing in the first position and allow relative rotation between the basket grapple and the housing in the second position.
2. The tool of claim 1, wherein the basket grapple includes a plurality of circumferentially spaced slots, wherein a each slot extends axially from the second end of the basket grapple and extends radially through the basket grapple from the outer surface of the basket grapple to the inner surface of the basket grapple;
- wherein the plurality of slots define a plurality of circumferentially adjacent fingers configured to flex radially outward.
3. The tool of claim 2, wherein the cutout extends axially from the first end of the basket grapple and one of the plurality of slots extends axially from the second end of the basket grapple to the cutout.
4. The tool of claim 2, wherein the inner surface of the basket grapple includes a plurality of teeth positioned on each finger, wherein the teeth are configured to engage a first flange.
5. The tool of claim 1, further comprising a door releasably coupled to the housing and covering the first access port, wherein the key extends from the door.
6. The tool of claim 5, wherein the door is coupled to the housing with a bolt, wherein the bolt includes a handle extending radially from the housing, wherein the handle is configured to allow a remotely operated vehicle to remove the bolt and manipulate the position of the housing subsea.
7. The tool of claim 1, wherein the housing includes a plurality of circumferentially spaced through slots axially positioned between the first end of the housing and the basket grapple, wherein each through slot in the housing extends radially through the housing from the inner surface of the housing to the outer surface of the housing;
- wherein a plate is mounted to the first end of the housing, the plate including a plurality of circumferentially spaced through bores;
- wherein the through slots in the housing and the through bores in the plate are configured to allow fluid flow from the inside of the housing to the outside of the housing.
8. The tool of claim 1, further comprising a plurality of circumferentially spaced guide feet coupled to the second end of the housing, wherein each foot has a first end engaging the housing, a second end extending from the second end of the housing, and a guide surface extending from the second end of the foot.
9. The tool of claim 8, wherein each foot is removably coupled to the housing and includes a finger extending radially inward along the second end of the housing, wherein the fingers of the plurality of guide feet are configured to prevent the basket grapple from moving axially through the second end of the housing.
10. The tool of claim 9, wherein each guide foot is removably coupled to the housing with a bolt, wherein the bolt includes a handle extending radially from the housing, and wherein the handle is configured to allow a remotely operated vehicle to remove the bolt subsea.
11. A method for removing a first flange of a subsea flange joint from a second flange of the subsea flange joint, the method comprising:
- (a) positioning a flange overshot retrieval tool over the subsea flange joint, wherein the tool comprises: a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface; an annular basket grapple coaxially threaded into the second end of the housing, wherein the basket grapple has a first end, and a second end opposite the first end;
- (b) receiving the first flange into the basket grapple;
- (c) radially expanding the basket grapple during (b); and
- (d) removing the first flange from the flange joint after (b).
12. The method of claim 11, further comprising:
- (e) preventing the rotation of the housing relative to the basket grapple with a key extending radially through the housing and the basket grapple.
13. The method of claim 11, wherein (b) further comprises guiding the first flange into the second end of the housing with a plurality of circumferentially spaced guide feet coupled to the second end of the housing;
- wherein each foot has a first end engaging the housing, a second end extending from the second end of the housing, and a guide surface extending axially downward and radially outward from the second end of the housing;
- wherein each guide foot includes a finger extending radially inward along the second end of the housing, wherein the fingers of the plurality of guide feet are configured to prevent the basket grapple from moving axially through the second end of the housing.
14. The method of claim 11, wherein the tool is positioned with a pipe string.
15. The method of claim 11, wherein the basket grapple further comprises a plurality of circumferentially spaced slots extending axially from the second end of the basket grapple;
- wherein the plurality of slots define a plurality of fingers at the second end of the basket grapple, each finger including a plurality of teeth disposed on the inner surface of the basket grapple;
- wherein (c) further comprises flexing the plurality of fingers radially outward during (b).
16. The method of claim 15, further comprising biasing the teeth radially inward into engagement with the first flange during (b).
17. A method comprising:
- (a) lowering a flange overshot retrieval tool to a subsea flange joint including a first flange coupled to a second flange, wherein the tool comprises: a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface; an annular basket grapple coaxially disposed in the second end of the housing, wherein the basket grapple has a first end, and a second end opposite the first end;
- (b) lowering the tool onto the first flange;
- (c) capturing the first flange with the basket grapple during (b); and
- (d) releasing the first flange from the basket grapple subsea after (c).
18. The method of claim 17, wherein (a) comprises lowering the tool with a pipe string; and
- wherein (d) further comprises: rotating the housing and the basket grapple relative to the first flange with the pipe string; and
- unthreading the basket grapple from the first flange.
19. The method of claim 17, wherein (a) comprises lowering the tool with a pipe string; and
- wherein (d) further comprises: rotating the housing relative to the basket grapple and the first flange with the pipe string; and unthreading the housing from the basket grapple.
20. The method of claim 19, wherein (d) further comprises:
- removing a plurality of guide feet coupled to the second end of the housing with one or more subsea remotely operated vehicles;
- allowing the housing to rotate relative to the basket grapple by removing a key extending radially through the housing and the basket grapple with the one or more subsea remotely operated vehicles.
21. The method of claim 20, further comprising:
- (e) lifting the housing from the basket grapple and the first flange.
22. The method of claim 17, further comprising:
- rotating the housing relative to the basket grapple and the first flange with a pipe string;
- accessing the basket grapple subsea through a port extending radially through the housing; and
- cutting the basket grapple subsea through the port with a subsea remotely operated vehicles.
Type: Application
Filed: Apr 25, 2012
Publication Date: Oct 25, 2012
Applicant: BP Corporation North America Inc. (Houston, TX)
Inventor: Paul Edward Anderson (Peyton, CO)
Application Number: 13/455,806
International Classification: E21B 19/16 (20060101); E21B 29/12 (20060101);