US20170107778A1

US20170107778A1 - Boltless Locking of BOP Bonnet

Info

Publication number: US20170107778A1
Application number: US14/886,706
Authority: US
Inventors: Kathiresan Krishnasamy; Raghavendra Muniswamy; Mareesan Bose; Manikandan Shenbagalingam
Original assignee: Hydril USA Distribution LLC
Current assignee: Hydril USA Distribution LLC
Priority date: 2015-10-19
Filing date: 2015-10-19
Publication date: 2017-04-20

Abstract

An apparatus for releasably connecting a bonnet to a body of a blowout preventer includes a latch plate that is mounted to the body of the blowout preventer. The latch plate has a plate profile on an outer surface of the latch plate. A clamping assembly extends through the bonnet and includes a clamping screw releasably secured to, and extending through the bonnet. A latch key is located at an inner end of the clamping screw, the latch key having a key profile shaped to mate with the plate profile and to resist relative movement between the latch key and the latch plate. The clamping assembly is moveable between an engaged position where the key profile mates with the plate profile, and a released position where the key profile is spaced apart from the plate profile.

Description

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure
The present disclosure relates in general to blowout preventers used in the hydrocarbon industry, and in particular to securing a bonnet to a blowout preventer.
2. Description of Related Art
Well control is an important aspect of oil and gas exploration. When drilling a well, for example, for oil and gas exploration applications, devices must be put in place to prevent injury to personnel and equipment associated with the drilling activities. One such well control device is a blowout preventer or BOP, which is typically installed at the surface or on the sea floor in deep water drilling arrangements. A BOP is generally used to seal a wellbore in order to control a “kick,” which occurs when a wellbore penetrates a geologic layer having a formation pressure substantially higher than the pressure maintained in the wellbore.
Common types of blowout preventers include annular blowout preventers and ram-type blowout preventers. Ram-type preventers typically comprise a body and at least two oppositely disposed ram assemblies secured to the blowout preventer body with a bonnet. The rams can be, for example, pipe rams (which, when activated, move to engage and surround drill pipe and well tools to seal the wellbore) or shear rams (which, when activated, move to engage and physically shear any drill pipe or well tools in the wellbore). The rams are typically located opposite of each other and, whether pipe rams or shear rams, the rams typically seal against one another proximate a center of the wellbore in order to completely seal the wellbore.
Blowout preventers must be regularly maintained. Moreover, it is often desirable to replace pipe rams with shear rams, or vice versa, to provide different well control options. Therefore, it is important that the blowout preventer includes bonnets that are easily removable so that interior components, such as the rams, may be accessed and maintained.
A traditional method of securing the bonnet with the body is by means of bolts which normally vary from 6 to 12 bolts, depending on the size and pressure rating of the blowout preventer. In ideal conditions, the time consumed to remove each bonnet bolt will be around 4-5 minutes, thereby consuming 30-45 minutes for every assembly or disassembly of the bonnet to the body.

SUMMARY OF THE DISCLOSURE

This application discloses systems and methods for releasably connecting a bonnet to a body of a blowout preventer that reduce the time required to remove and replace the bonnet on the body of the blowout preventer.
In an embodiment of the current disclosure, an apparatus for releasably connecting a bonnet to a body of a blowout preventer includes a latch plate that is mounted to the body of the blowout preventer, the latch plate having a plate profile on an outer surface of the latch plate. A clamping assembly extends through the bonnet. The clamping assembly has a clamping screw releasably secured to, and extending through the bonnet. The clamping assembly also includes a latch key located at an inner end of the clamping screw. The latch key has a key profile shaped to mate with the plate profile and to resist relative movement between the latch key and the latch plate. The clamping assembly is moveable between an engaged position where the key profile mates with the plate profile, and a released position where the key profile is spaced apart from the plate profile.
In an alternate embodiment of the current disclosure, a blowout preventer assembly with an apparatus for releasably connecting a bonnet to the blowout preventer is disclosed. The blowout preventer assembly includes a blowout preventer with a body. A latch plate is mounted to the body, the latch plate having a plate profile on an outer surface of the latch plate. A clamping assembly extends through the bonnet. The clamping assembly includes a clamping screw releasably secured to, and extending through the bonnet. The clamping assembly also includes a latch key located at an inner end of the clamping screw. A ram assembly extends radially from the body and is secured to the bonnet. The latch key has a key profile shaped to mate with the plate profile and to resist relative movement between the latch key and the latch plate in a direction along a central ram axis of the ram assembly. The clamping assembly is moveable between an engaged position where the key profile mates with the plate profile, and a released position where the key profile is spaced apart from the plate profile.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.

FIG. 1 is a perspective view of a blowout preventer with a latching apparatus for releasably connecting a bonnet to a body of the blowout preventer, in accordance with an embodiment of this disclosure, shown with a portion of the bonnet cut away to view the latching apparatus.

FIG. 2 is a detail view of a portion of a partial section perspective view of the blowout preventer of FIG. 1.

FIG. 3 is a top section view of the latching apparatus of FIG. 1, with the latching apparatus in a released position.

FIG. 4 is a top section view of the latching apparatus of FIG. 1, with the latching apparatus in an engaged position.

DETAILED DESCRIPTION OF THE DISCLOSURE

The systems and methods of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings which illustrate embodiments of the invention. The system and method if this disclosure may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and the prime notation, if used, indicates similar elements in alternative embodiments.
Referring to FIG. 1, blowout preventer 10 with latching apparatus 12 is shown. Blowout preventer 10 includes body 14 that has central bore 16 that extends from a bottom end of blowout preventer body 14 to a top end of blowout preventer body 14. In the example blowout preventer 10 of FIG. 1, there are two pairs of ram assemblies 18, for a total of four ram assemblies 18. Each ram assembly 18 extends radially from the body 14 of blowout preventer 10 so that central ram axis 20 is in a direction generally perpendicular to central bore 16. A pair of ram assemblies 18 includes two ram assemblies 18 that are located on opposite sides of blowout preventer 10 so that the rams within each ram assembly 18 of the pair of ram assemblies 18 can extend to mate within central bore 16.
Ram assemblies 18 can be blind rams, sealing rams, shear rams, blind shear rams, pipe rams, or other known types of rams used in blowout preventers 10. Blowout preventer 10 can include more than one type of ram assembly 18. In alternate embodiments, blowout preventer 10 can have only one pair of ram assemblies 18 or can have more than two pairs of ram assemblies 18.
Each ram assembly 18 is secured to body 14 of blowout preventer 10 with bonnet 22. Each ram assembly 18 can be secured to bonnet 22 with bolts or other known connection means. Bonnet 22 is then secured to body 14 of blowout preventer 10 with latching apparatus 12. In the example embodiment of FIG. 1, bonnet 22 has a front portion 24 to which the ram assembly 18 is secured. Bonnet 22 also has two side portions 26 located on opposite sides of front portion 24. When assembled with blowout preventer 10, front portion 24 will engage an outer face 28 of body 14 of blowout preventer 10 and side portions 26 will extend along recessed sides 30 of body 14 of blowout preventer 10. Recessed sides 30 are regions of blowout preventer body 14 that have a narrower width W, measured perpendicular to central ram axis 20, than the width of preventer body 14 through central bore 16.
Turning to FIGS. 2-4, latching apparatus 12 includes latch plate 32. Latch plate 32 is mounted to body 14 of blowout preventer 10. In the example embodiment of FIGS. 3-4, latch plate 32 is secured to blowout preventer body 14 with threaded members 34, such as screws, that extend through latch plate 32 and into blowout preventer body 14. Guide pins 36 can help to align latch plate 32 with blowout preventer body 14 while latch plate 32 is being attached to blowout preventer body 14 with threaded members 34. Guide pins 36 also extend through latch plate 32 and into blowout preventer body 14. Looking at FIG. 2, six members are shown extending through latch plate 32 on one side of latch plate 32. In such an embodiment, six other members would extend through latch plate 32 on the other side of plate 32 (not shown). On each side, five such members can be threaded members 34 and one can be a guide pin 36 so that each latch plate 32 has ten threaded members and two guide pins 36. The embodiment of FIGS. 1-4 is for example only and in other embodiments, a different combination of the number of threaded members 34 and guide pins 36 can be used to secure latch plate 32 to blowout preventer body 14. In other alternate embodiments, other means can be used for attaching latch plate 32 to blowout preventer body 14.
Latch plate 32 has plate profile 38 on an outer surface of latch plate 32. The shape and purpose of plate profile 38 will be discussed below.
Looking at FIGS. 3-4, latching apparatus 12 also includes clamping assembly 40 that extends through bonnet 22. Latching apparatus 12 includes clamping screw 42 and latch key 44. Clamping screw 42 extends through bonnet 22 and is releasably secured to bonnet 22. In the example embodiment, clamping screw 42 is threaded to bonnet 22 and has an internal bore 46. Clamping screw 42 can be a quarter turn fastener so that clamping screw 42 can be secured to and released from bonnet 22 by rotating clamping screw 42 less than one hundred and eighty degrees, and in certain embodiments, by rotating clamping screw 42 ninety degrees. In the example of FIGS. 1-2, each clamping assembly 40 includes two clamping screws 42. In alternate embodiments, one clamping screw 42 or more than two clamping screws 42 can be used for each clamping assembly 40.
In one embodiment, for each ram assembly 18, a latch plate 32 is located on a first side of the body 14 of the blowout preventer 10 and clamping assembly 40 extends through a first side of bonnet 22. A second latch plate 32 is located on a second side of body 14 of blowout preventer 10 and a second clamping assembly 40 extends through a second side of bonnet 22 for the same ram assembly 18. Therefore in the example embodiment of FIGS. 1-2, with four ram assemblies 18, there are eight latch plates 32 and eight clamping assemblies 40 in total.
Latch key 44 is located at an inner end of clamping screw 42. Latch key 44 has a key profile 48 that is shaped to mate with plate profile 38. Clamping assembly 40 is moveable between an engaged position (FIG. 4) where key profile 48 mates with plate profile 38, and a released position (FIG. 3) where key profile 48 is spaced apart from plate profile 38. Rotating clamping screw 42 in a first direction causes clamping screw 42 to travel in a direction into bonnet 22 and move key profile 48 into engagement with plate profile 38. Rotating clamping screw 42 in a second direction causes clamping screw 42 to travel in a direction out of bonnet 22 and move key profile 48 out of engagement with plate profile 38.
When key profile 48 mates with plate profile 38, the interaction of key profile 48 and plate profile 38 restricts relative movement between latch key 44 and latch plate 32. Key profile 48 is shaped to resist relative movement between latch key 44 and latch plate 32 in a radially outward direction D when clamping assembly 40 is in the engaged position. Radially outward direction D is parallel with central ram axis 20. When clamping assembly 40 is in the released position, bonnet 22 is removable from blowout preventer body 14 by moving bonnet 22 away from blowout preventer body 14 in the radially outward direction D.
In the example embodiments of FIGS. 3-4, key profile 48 and plate profile 38 are shown with generally saw tooth patterned shapes. Plate profile 38 has longer sloped surfaces that face generally outward away from central ram axis 20 and shorter slopes surfaces that face generally opposite to radially outward direction D. Key profile 48 has longer sloped surfaces that face generally inward towards central ram axis 20 and shorter slopes surfaces that face generally in radially outward direction D. It is the interaction of the shorter sloped surfaces of plate profile 38 and key profile 48 that resist relative movement between latch key 44 and latch plate 32 in a radially outward direction D when clamping assembly 40 is in the engaged position.
In the example embodiment of FIGS. 3-4, clamping assembly 40 also includes lock screw 50 that releasably secures latch key 44 to clamping screw 42. Lock screw 50 is housed within internal bore 46 of clamping screw 42 and carried by clamping screw 42. Lock screw 50 can have an end portion 52 that threads into latch key 44. Lock screw 50 and clamping screw 42 can be rotated relative to each other so that rotating one of lock screw 50 and clamping screw 42 will not cause the other to rotate. Lock screw 50 can have an opposite thread direction than clamping screw 42 so that, as an example, turning clamping screw 42 in a clockwise direction will cause clamping screw 42 to travel in a direction into bonnet 22, while turning lock screw 50 in a clockwise direction would cause lock screw 50 to travel in a direction out of latch key 44.
In an example of operation, latch plate 32 can be mounted to body 14 of blowout preventer 10. Clamping screw 42 can be located through bonnet 22 and fastened to latch key 44 by rotating lock screw 50 in a second direction, such as a counterclockwise direction. Bonnet 22 with ram assembly 18 can be placed on blowout preventer body 14, and clamping screw 42 can be rotated in a first direction, such as a clockwise direction, to move clamping assembly 40 to the engaged position where key profile 48 mates with plate profile 38. All of the clamping screws 42 of clamping assemblies 40 that are located on either side of blowout preventer body 14 will be rotated a quarter turn to move the clamping assemblies 40 to the engaged position.
With clamping assembly 40 in the engaged position, the mating of key profile 48 with plate profile 38 will resist relative movement between latch key 44 and latch plate 32 in radially outward direction D. Therefore ram assemblies 18 will remain tightly secured to blowout preventer body 14 even when forces between ram assemblies 18 and blowout preventer body 14 during operation of blowout preventer 10 would act against ram assemblies 18 in a radially outward direction D.
If there is a need or desire to remove bonnet 22 from blowout preventer body 14, clamping assembly 40 can be moved to the released position by rotating each of the clamping screws 42 a quarter turn in a second direction, such as a counterclockwise direction, and removing bonnet 22 with ram assembly 40 from blowout preventer body 14 in the radially outward direction D.
The terms “vertical”, “horizontal”, “upward”, “downward”, “above”, and “below” and similar spatial relation terminology are used herein only for convenience because elements of the current disclosure may be installed in various relative positions.
While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.

Claims

What is claimed is:

1. An apparatus for releasably connecting a bonnet to a body of a blowout preventer, the apparatus comprising:

a latch plate that is mounted to the body of the blowout preventer, the latch plate having a plate profile on an outer surface of the latch plate;

a clamping assembly that extends through the bonnet, the clamping assembly comprising:

a clamping screw releasably secured to, and extending through the bonnet; and

a latch key located at an inner end of the clamping screw, the latch key having a key profile shaped to mate with the plate profile and to resist relative movement between the latch key and the latch plate; and wherein

the clamping assembly is moveable between an engaged position where the key profile mates with the plate profile, and a released position where the key profile is spaced apart from the plate profile.

2. The apparatus according to claim 1, further comprising a lock screw releasably securing the latch key to the clamping screw.

3. The apparatus according to claim 1, wherein the latch plate is located on a first side of the body of the blowout preventer and the clamping assembly extends through a first side of the bonnet, and wherein the apparatus further comprises a second latch plate located on a second side of the body of the blowout preventer and a second clamping assembly extending through a second side of the bonnet.

4. The apparatus according to claim 1, wherein the clamping screw is threaded to the bonnet and has an internal bore housing a lock screw that releasably secures the latch key to the clamping screw.

5. The apparatus according to claim 1, wherein the clamping screw is a quarter turn fastener.

6. The apparatus according to claim 1, wherein the key profile is shaped to resist relative movement between the latch key and the latch plate in a radially outward direction when the clamping assembly is in the engaged position, and wherein the bonnet is removable from the body of the blowout preventer in the radially outward direction when the clamping assembly is in the released position.

7. A blowout preventer assembly with an apparatus for releasably connecting a bonnet to a blowout preventer, the blowout preventer assembly comprising:

a blowout preventer with a body;

a latch plate that is mounted to the body, the latch plate having a plate profile on an outer surface of the latch plate;

a clamping screw releasably secured to, and extending through the bonnet; and

a latch key located at an inner end of the clamping screw;

a ram assembly extending radially from the body and secured to the bonnet, the latch key having a key profile shaped to mate with the plate profile and to resist relative movement between the latch key and the latch plate in a direction along a central ram axis of the ram assembly; and wherein

8. The blowout preventer assembly according to claim 7, further comprising a lock screw releasably securing the latch key to the clamping screw, the lock screw being carried by the clamping screw.

9. The blowout preventer assembly according to claim 7, wherein the latch plate is located on a first side of the ram assembly, and wherein the apparatus further comprises a second latch plate located on a second side of the ram assembly.

10. The blowout preventer assembly according to claim 7, wherein the clamping screw is threaded to the bonnet and has an internal bore housing a lock screw that releasably secures the latch key to the clamping screw.

11. The blowout preventer assembly according to claim 7, wherein the clamping screw is a quarter turn fastener.

12. The blowout preventer assembly according to claim 7, wherein the bonnet and the ram assembly is removable from the body in the direction along the central ram axis of the ram assembly when the clamping assembly is in the released position.

13. A method for releasably connecting a bonnet to a body of a blowout preventer, the method comprising:

mounting a latch plate to the body of the blowout preventer, the latch plate having a plate profile on an outer surface of the latch plate;

extending a clamping assembly through the bonnet, the clamping assembly comprising a clamping screw releasably secured to, and extending through the bonnet, and a latch key located at an inner end of the clamping screw, the latch key having a key profile shaped to mate with the plate profile; and

moving the clamping assembly from a released position where the key profile is spaced apart from the plate profile to an engaged position where the key profile mates with the plate profile and resists relative movement between the latch key and the latch plate.

14. The method according to claim 13, further comprising releasably securing the latch key to the clamping screw with a lock screw.

15. The method according to claim 13, further comprising locating the latch plate on a first side of the body of the blowout preventer and extending the clamping assembly through a first side of the bonnet, and wherein the method further comprises locating a second latch plate on a second side of the body of the blowout preventer and extending a second clamping assembly through a second side of the bonnet.

16. The method according to claim 13, further comprising threading the clamping screw to the bonnet by rotating the clamping screw in a first direction and releasably securing the latch key to the clamping screw with a lock screw that is housed in an internal bore of the clamping screw, by rotating the lock screw in a second direction.

17. The method according to claim 13, further comprising releasably securing the clamping screw to the bonnet by rotating the clamping screw less than one hundred and eighty degrees.

18. The method according to claim 13, wherein the key profile is shaped to resist relative movement between the latch key and the latch plate in a radially outward direction when the clamping assembly is in the engaged position, the method further comprising moving the clamping assembly to the released position and removing the bonnet from the body of the blowout preventer in the radially outward direction.