Modular blowout preventer

Abstract

A modular blowout preventer includes a first chamber, a main body, and a second chamber all mated together and held fast via a plurality of braces linking the first chamber to the second chamber. The main body having a through bore and a passage transverse to the through bore running across all three modular components. A shearing element is configured to sever objects in the through bore.

Description

MODULAR BLOWOUT PREVENTERCross-Reference to Related Applications

[0001] Not applicable.Background

[0002] Blowout preventers (BOPs) for oil and gas wells are used to prevent potentially catastrophic events known as blowouts, where high well pressures and uncontrolled flow from a subsurface formation into the well can expel tubing (e.g., drill pipe and well casing), tools and drilling fluid out of a well. Blowouts present a serious safety hazard to drilling crews, the drilling rig and the environment and can be extremely costly. Typically BOPs have “rams” that are opened and closed by actuators. The most common type of actuator is operated hydraulically to push closure elements across a through bore in a BOP housing to close the well. In some cases, the rams have shears to cut through a drill string or other tool which may be in the well at the time it is necessary to close the BOP.

[0003] Pyrotechnic gas pressure operated BOPs have also been implemented. An example of such a pyrotechnic gas pressure operated BOP is described in U.S. Patent 10,465,466 issued to Kinetic Pressure Control, Ltd. Such BOPs are referred to as “kinetic” BOPs. FIG. 1 shows a side view of a conventional kinetic BOP 100. The unit consists of a main body section 10. On one end of the main body section 10, a pressure housing 12 is mounted and rigidly secured via a series of massive tie rods 14 that screw into the main body section at one end. At the other end of the tie rods 14, the rod ends pass through holes in an end cap 16 and are secured via nuts 18. On the opposite end of the main body section 10, a receiving housing 20 is mounted and rigidly secured via a series of massive tie rods 22 that screw into the main body section at one end. At the other end of the tie rods 22, the rod ends pass through holes in an end cap 24 and are secured via nuts 26.

[0004] Since kinetic BOPs use internal pyrotechnic charges to generate the propulsion force required to shear objects in the through bore, such BOPs experience high internal pressures as the charge is ignited resulting in rapid gas expansion. To safely contain such rapidly expanding gas pressures, the BOPs are generally formed from high-strength metals (e.g., steel) with thick walls. In addition to the high-strength component materials, the BOPs are also implemented with the massive tie rods 14, 22to maintain the components securely in place, ensuring system integrity. In some embodiments, the tie rods 14, 22 are torqued in the range of several thousand pounds per foot. Accordingly, the manufacturing and production costs of such kinetic BOPs are high, and disassembly for testing / maintenance is time consuming, commonly requiring specialized tools. A need remains for improved kinetic BOP systems.Summary

[0005] One aspect of the present disclosure is a blowout preventer including a main body having a through bore. A first chamber transverse to the through bore is disposed at one end of the main body. A second chamber transverse to the through bore is disposed at a second end of the main body opposite the first chamber. A first brace is disposed at one side of the main body, linking the first chamber to the second chamber. A second brace is disposed at a second side of the main body, linking the first chamber to the second chamber. A shearing element is configured to selectively cut objects disposed in the through bore.

[0006] Another aspect of the present disclosure is a blowout preventer including a main body having a through bore. A pressure chamber transverse to the through bore is disposed at one end of the main body. A receiving chamber transverse to the through bore is disposed at a second end of the main body opposite the pressure chamber. The pressure chamber is linked to the receiving chamber via a plurality of braces. The main body is sandwiched between the linked pressure chamber and receiving chamber.

[0007] Another aspect of this disclosure relates to a method for operating a blowout preventer. The blowout preventer comprises a main body having a through bore, a first chamber transverse to the through bore and disposed at one end of the main body, a second chamber transverse to the through bore and disposed at a second end of the main body opposite the first chamber, a first brace disposed at one side of the main body to link the first chamber to the second chamber, a second brace disposed at a second side of the main body to link the first chamber to the second chamber. The method comprises activating a shearing element to move across the through bore to cut an object disposed in the through bore.Brief Description of the Drawings

[0008] The following figures form part of the present specification and are included to further demonstrate certain aspects of the present disclosure and should not be used to limit the claimed subject matter. A more complete understanding of the disclosed embodiments and further features and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numerals may identify like elements.

[0009] FIG. 1 shows a side view of a conventional kinetic blowout preventer.

[0010] FIG. 2 shows a perspective view of a kinetic blowout preventer embodiment according to this disclosure.

[0011] FIG. 3 shows a schematic of a linking brace embodiment according to this disclosure.

[0012] FIG. 4 shows another perspective view of a kinetic blowout preventer embodiment according to this disclosure.

[0013] FIG. 5 shows a side view of a kinetic blowout preventer embodiment according to this disclosure.

[0014] FIG. 6 shows a cross section of a kinetic blowout preventer embodiment according to this disclosure in a pre-activation state.

[0015] FIG. 7 shows a cross section of a kinetic blowout preventer embodiment according to this disclosure in a post-activation state.Detailed Description

[0016] The foregoing description of the figures is provided for the convenience of the reader. It should be understood, however, that the embodiments are not limited to the precise arrangements and configurations shown in the figures. In the development of any actual embodiment, numerous implementation-specific decisions may need to be made to achieve the design-specific goals, which may vary from one implementation to another. It will be appreciated that such a development effort, while possibly complex and time-consuming, would nevertheless be a routine undertaking for persons of ordinary skill in the art having the benefit of this disclosure.

[0017] FIG. 2 shows a perspective view of a BOP 200 embodiment according to this disclosure. The apparatus has a main body 202 with a through bore 204 running from top to bottom along an axis perpendicular to a longitudinal axis. Tn this embodiment, the main body 202 is configured with a flange 206 extending from one surface for connection to a conventional tubular coupling (e.g., wellhead) as known in the art. The opposite surface is shown with a plurality of bolts 208 threaded thereon for coupling to a conventional tubular coupling. A first chamber 210 transverse to the through bore 204 is disposed at one end of the main body 202. A second chamber 212 transverse to the through bore 204 is disposed at a second end of the main body 202 opposite the first chamber. A first brace 214 is disposed at one side of the main body 202, linking the first chamber 210 to the second chamber 212. A second brace 216 is disposed at a second side of the main body 202, linking the first chamber 210 to the second chamber 212.

[0018] As shown in FIG. 2, some embodiments are implemented with a plurality of short tie rods 216 disposed along the exterior of the first chamber 210. The tie rods 216 couple into threaded orifices 218 formed in a mating surface 220 that abuts against the main body 202 at one end of the first chamber 210. At the opposite or distal end of the first chamber 210, the tie rod 216 ends pass through holes 222 in an end cap 224 and are securely fastened thereon with nuts 226. The tie rods 216 are tightened to apply a tension force along the longitudinal axis of the first chamber 210, enhancing the structural integrity of the chamber to sustain the rapid internal gas expansion during operation (further described below). Some embodiments may also be implemented with a locking mechanism 40 as described in U.S. Patent 11,480,031, assigned to Kinetic Pressure Control Ltd., and entirely incorporated herein by reference.

[0019] FIG. 3 shows a side view of a brace 214 embodiment of this disclosure. It will be understood that the first 214 and second 216 braces may be formed with identical configurations. As shown in FIG. 3, the brace has a general dog bone shape, with a narrow central region 230, a wide first end 232 and wide second end 234. One or more internal threaded receptacles 236 are formed on each end 232, 234 of the braces 214, 216. The braces 214, 216 may be formed of any suitable material that can sustain significant tensile stress (e.g., hardened metals, alloys, etc.).

[0020] FIG. 4 shows the BOP 200 embodiment of FIG. 2 from another perspective. The first chamber 210 is shown mated against the main body 202 on one end and the second chamber 212 mated to the opposite end of the main body. FIG. 4 shows a first brace 214 disposed on one side of the main body 202, linked at a first end 232 to the mating surface 220 at one end of the first chamber 210. In this embodiment, the first end 232 of the brace 214 is configured with multiple threaded receptacles 236 (see FIG. 3) to receive threaded studs 238. The threaded studs 238 pass through holes 240 formed in the mating surface 220. The mating surface 220 is held secure against the first end 232 of the brace 214 via a nut 242 tightened onto each stud 238, forming a rigid junction between the brace and the first chamber 210. The second end 234 of the first brace 214 is similarly coupled to a mating surface 244 at one end of the second chamber 212 via multiple studs 238 passing through holes 246 formed thereon and nuts 242 tightened onto the studs. A second brace 216 is disposed at the second side of the main body 202, likewise linking the first chamber 210 to the second chamber 212 on that side of the main body.

[0021] As shown in FIG. 4, embodiments may be implemented with the first 214 and / or second 216 brace configured with a cover 248 mounted onto the exterior surface of the brace body. The cover 248 may be used to shield wiring or electronic components associated with the BOP 200 and run along the brace 214, 216 for efficiency. The cover 248 may be formed of any suitable material and affixed to the brace 214, 216 via any means as known in the art (e.g., fasteners, adhesives, etc.).

[0022] FIG. 5 shows a side view of a BOP 200 embodiment of this disclosure. As shown in the figure, the main body 202 module is sandwiched between the first chamber 210 and second chamber 212. A first brace 214 is coupled to the first chamber 210 and second chamber 212 as described herein. Although not visible in FIG. 5, a second brace 216 on the back side of the BOP 200 likewise couples the first and second chambers 210, 212. In this manner, the main body 202 is free of any tensional stresses, improving the structural integrity of the module and its internal passages.

[0023] FIG. 6 shows a cross section of a BOP 200 embodiment of this disclosure. For clarity of illustration, the BOP 200 is shown without a brace 214, 216 and without tie rods 216. FIG. 6 shows the individual modular BOP 200 components, from left to right, the first chamber 210, main body 202, and second chamber 212. The main body 202has a through bore 204 running through the entire body to provide a wellbore when coupled onto a well. As shown in FIG. 6, the first chamber 210, the main body 202, and the second chamber 212 respectively each have a passage 250A, 250B, 250C formed therein oriented transversely to the through bore 204. When the three modular BOP 200 sections are mated together and linked via the first brace 214 and second brace 216, the three passages 250A, 250B, 250C align to form one transverse passage. A shearing element 252 is disposed in the transverse passage 250B to selectively cut an object (e.g., tubular, tool, wire, etc.) when the object is in the through bore 204. In some embodiments, the shearing element 252 consists of a ring cutter as described in International Patent Application PCT / US2020 / 048701 , assigned to Kinetic Pressure Control, Ltd. and entirely incorporated herein by reference.

[0024] The first chamber 210 module forms a pressure housing including a piston 254 and a gate 256 disposed therein. The gate 256 may be a flat plate shaped to enable longitudinal motion along the transverse passage 250A, 250B, 250C and to act in the same manner as a gate in a gate valve to close the through bore 204. A charge 258, which may be in the form of a pyrotechnic, heat, and / or percussively initiated chemical propellant, is located between the piston 254 and an end cap 260 at the distal end of the first chamber 210 opposite the main body 202. The charge 258 may be initiated, by an initiator 262 disposed in the end cap 260, to combust or react to produce high pressure gases, which in turn propel the piston 254 and thus the gate 256 through the first chamber 210 and into the shearing element 252. Kinetic energy from the piston 254 and the gate 256 are transferred to the shearing element 252 to propel the element across the through bore 204 to sever any objects in the bore. The gate 256 and shearing element 252 may remain in intimate contact as they travel across the through bore 204 allowing the force from the expanding gases to continue to act through the piston 254 and gate and onto the shearing element during shearing to increase severing effectiveness.

[0025] FIG. 7 shows a cross section view of the blowout preventer 200 after the charge 258 has been activated and the shearing element 252 has sheared through anything that may have been in the through bore 204. The front face of the piston 254 has now engaged an arresting mechanism 264 in the transverse passage 250A. In some embodiments, the arresting mechanism 264 is formed from an energy absorbing material that crumples as it absorbs the kinetic energy of the piston 254 and the gate 256. At this stage, the shearing element 252 has been propelled across the though bore204 to end up in the transverse passage 250C in the third chamber 212. Embodiments of the BOP 200 can be operated as described in U.S. Patent 11,028,664, assigned to Kinetic Pressure Control, Ltd. and entirely incorporated herein by reference.

[0026] The disclosed BOP 200 embodiments offer advantages over conventional BOP systems. By eliminating the need for massive cross-system tie rods (14, 22 in FIG. 1), the disclosed BOPs reduce manufacturing complexity and costs. The modular components of the disclosed BOPs are easier to assemble and disassemble for repair, maintenance, and testing operations. Elimination of the massive cross-system tie rods in the disclosed BOPs also reduces the stress imposed on the main body as the main body is now free of any tension stresses formerly imposed by the tie rods threaded into the main body from both ends. The main body 202 now resides tension free, sandwiched between two outer modular components 210, 212.

[0027] Considering the principles and example embodiments described and illustrated herein, it will be recognized that the example embodiments can be modified in arrangement and detail without departing from such principles. It will be appreciated by those skilled in the art that conventional electronics, software, controllers, and components may be used to implement the embodiments according to this disclosure. It will also be appreciated that BOP 200 components may be formed of any suitable materials (e.g., metal, composites, alloys, etc.). Embodiments of this disclosure may also be implemented for use at surface as well as in underwater applications and operations, in the oil and gas industry, and in other fields of endeavor.

Claims

ClaimsWhat is claimed is:

1. A blowout preventer (BOP) comprising: a main body having a through bore; a first chamber transverse to the through bore and disposed at one end of the main body; a second chamber transverse to the through bore and disposed at a second end of the main body opposite the first chamber; a first brace disposed at one side of the main body, linking the first chamber to the second chamber; a second brace disposed at a second side of the main body, linking the first chamber to the second chamber; and a shearing element configured to selectively cut objects disposed in the through bore.

2. The BOP of claim 1 wherein the first chamber consists of a pressure chamber.

3. The BOP of claim 1 wherein the main body, the first chamber, and the second chamber each comprise a passage transverse to the through bore.

4. The BOP of claim 3 wherein the shearing element is configured for movement along the transverse passage in the main body.

5. The BOP of claim 3 further comprising a piston disposed in the first chamber, configured to move a gate along the transverse passage in the main body.

6. The BOP of claim 5 wherein the gate is configured to propel the shearing element across the through bore.

7. The BOP of claim 1 further comprising at least one locking element disposed on the first chamber.

8. The BOP of claim 1 wherein the first brace and the second brace are each respectively coupled to the first and second chambers by a nut fastened to a stud.

9. The BOP of claim 1 wherein the first brace and the second brace are each configured in a generally dog bone shape.

10. The BOP of claim 1 further comprising a plurality of rods disposed on the first chamber and configured to apply a tension force along a longitudinal axis of the chamber.

11. The BOP of claim 1 wherein the first chamber is configured to house a gas generating charge.

12. The BOP of claim 1 further comprising an arresting mechanism.

13. A method for operating a blowout preventer (BOP), the BOP comprising a main body having a through bore, a first chamber transverse to the through bore and disposed at one end of the main body, a second chamber transverse to the through bore and disposed at a second end of the main body opposite the first chamber, a first brace disposed at one side of the main body to link the first chamber to the second chamber, a second brace disposed at a second side of the main body to link the first chamber to the second chamber, the method comprising activating a shearing element to move across the through bore to cut an object disposed in the through bore.

14. The method of claim 13 wherein the first chamber is configured with a plurality of rods disposed thereon to apply a tension force along a longitudinal axis of the chamber.

15. The method of claim 13 wherein the main body, the first chamber, and the second chamber each comprise a passage transverse to the through bore.

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