AIR-FREIGHTABLE CONTAINMENT CAP FOR CONTAINING A SUBSEA WELL
A modular containment cap for containing a subsea wellbore discharging hydrocarbons comprises a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end. In addition the containment cap comprises an upper assembly including a spool piece having an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, and a first spool piece valve disposed in the throughbore. The first spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece. The upper end of the spool body is releasably connected to the lower end of the spool piece, and the first throughbore of the spool body is coaxially aligned with and in fluid communication with the throughbore of the spool piece.
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This application claims benefit of U.S. provisional patent application Ser. No. 61/498,269 filed Jun. 17, 2011, and entitled “Air-Freightable Containment Cap for Containing a Subsea Well,” which is hereby incorporated herein by reference in its entirety. This application also claims benefit of U.S. provisional patent application Ser. No. 61/500,679 filed Jun. 24, 2011, and entitled “Subsea Containment Cap Adapter,” 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 systems and methods for containing a subsea wellbore that is discharging hydrocarbons. More particularly, the invention relates to systems and methods for capping a subsea wellbore at the flex joint of the lower marine riser package, the blowout preventer (BOP), or wellhead, and controlling the discharge of hydrocarbons into the surrounding sea. Still more particularly, the invention relates to a modular, air-freightable system for capping a subsea blowout preventer or lower marine riser package and controlling the discharge of hydrocarbons into the surrounding sea.
2. Background of the Technology
In offshore drilling operations, a blowout preventer (BOP) is installed on a wellhead at the sea floor and a lower marine riser package (LMRP) is mounted to the BOP. In addition, a drilling riser extends from a flex joint at the upper end of LMRP to a drilling vessel or rig at the sea surface. A drill string is then suspended from the rig through the drilling riser, LMRP, and the BOP into the well bore. A choke line and a kill line are also suspended from the rig and coupled to the BOP, usually as part of the drilling riser assembly.
During drilling operations, drilling fluid, or mud, is delivered through the drill string, and returned up an annulus between the drill string and casing that lines the well bore. In the event of a rapid influx of formation fluid into the annulus, commonly known as a “kick,” the BOP and/or LMRP may actuate to seal the annulus and control the well. In particular, BOPs and LMRPs comprise closure members capable of sealing and closing the well in order to prevent the release of gas or liquids from the well. Thus, the BOP and LMRP are used as devices that close, isolate, and seal the wellbore. Heavier drilling mud may be delivered through the drill string, forcing fluid from the annulus through the choke line or kill line to protect the well equipment disposed above the BOP and LMRP from the pressures associated with the formation fluid. Assuming the structural integrity of the well has not been compromised, drilling operations may resume. However, if drilling operations cannot be resumed, cement or heavier drilling mud may be delivered into the well bore to kill the well.
In the event that the wellbore is not sealed, a blowout may occur. The blowout may damage subsea equipment and/or connections between subsea equipment. This can be especially problematic if it results in the discharge of hydrocarbons into the surrounding sea water. In addition, it may be challenging to rectify remotely as the discharge may be hundreds or thousands of feet below the sea surface.
In the event such a subsea blowout results in the discharge of hydrocarbons into the surrounding sea, the amount of time it takes to cap and/or shut-in the well is important (i.e., the more time it takes, the more hydrocarbons are discharged into the surrounding water). One possible approach to capping and shutting-in a subsea well is to obtain a second BOP, lower the second BOP subsea, couple the second BOP to the upper end of the subsea BOP or LMRP that is discharging hydrocarbons, and then utilize the second BOP to shut-in the well. However, due to their sheer size and weight, most conventional BOPs are not transportable by air. Accordingly, identifying, obtaining, and transporting a suitable conventional BOP for use in capping a subsea blowout may be time consuming and inefficient.
Accordingly, there remains a need in the art for systems and methods to cap a subsea well. Such systems and methods would be particularly well-received if they offered the potential to cap a subsea well discharging hydrocarbon fluids and were air-freightable.
BRIEF SUMMARY OF THE DISCLOSUREThese and other needs in the art are addressed in one embodiment by a modular containment cap for containing a subsea wellbore discharging hydrocarbons into the surrounding sea. In an embodiment, the containment cap comprises a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end. In addition the containment cap comprises an upper assembly including a spool piece having an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, and a first spool piece valve disposed in the throughbore. The first spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece. The upper end of the spool body is releasably connected to the lower end of the spool piece, and the first throughbore of the spool body is coaxially aligned with and in fluid communication with the throughbore of the spool piece.
These and other needs in the art are addressed in another embodiment by a method for containing and/or producing a subsea wellbore discharging hydrocarbons into the surrounding sea. A wellhead is disposed at the sea floor at the upper end of the wellbore, a subsea BOP is mounted to the wellhead, an LMRP is mounted to the BOP, and a riser extends from the LMRP. In an embodiment, the method comprises (a) selecting a subsea landing site from one of the BOP, the LMRP, or the wellhead. In addition, the method comprises (b) preparing the landing site for connection to a modular containment cap. The containment cap comprises a lower assembly including a spool body and an upper assembly including a spool piece. Further, the method comprises (c) transporting the lower assembly and the upper assembly to an offshore location. Still further, the method comprises (d) lowering the lower assembly subsea and releasably connecting the lower assembly to the landing site. Moreover, the method comprises (e) lowering the upper assembly subsea and releasably connecting the upper assembly to the lower assembly. Moreover, the method comprises (f) shutting in the wellbore with the containment cap after (d) and (e).
These and other needs in the art are addressed in another embodiment by a containment cap for containing a subsea wellbore discharging hydrocarbons into the surrounding sea. In an embodiment, the containment cap comprises a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end. In addition, the containment cap comprises a valve assembly slidingly disposed in the first throughbore. The valve assembly comprises a tubular body and a first spool body valve. The tubular body has an upper end extending from the first throughbore, a lower end disposed within the first throughbore, and a throughbore extending between the upper end and the lower end of the tubular body. The first spool body valve is disposed along the throughbore of the tubular body and is configured to control the flow of fluids through the throughbore of the tubular body. Further, the containment cap comprises a plurality of annular seal assemblies radially positioned between the spool body and the tubular body. Each seal assembly is configured to restrict the flow of fluids between the tubular body and the spool body.
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 suggest in any way 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 component couples to a second component, that connection may be through a direct engagement between the two components, or through an indirect connection via other intermediate devices, components, and/or connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the given axis, and a radial distance means a distance measured perpendicular to the given axis.
Referring now to
Downhole operations are carried out by a tubular string 116 (e.g., drillstring, production tubing string, coiled tubing, etc.) that is supported by derrick 111 and extends from platform 110 through riser 115, LMRP 140, BOP 120, and into cased wellbore 101. A downhole tool 117 is connected to the lower end of tubular string 116. In general, downhole tool 117 may comprise any suitable downhole tool(s) for drilling, completing, evaluating and/or producing wellbore 101 including, without limitation, drill bits, packers, testing equipment, perforating guns, and the like. During downhole operations, string 116, and hence tool 117 coupled thereto, may move axially, radially, and/or rotationally relative to riser 115, LMRP 140, BOP 120, and casing 131.
BOP 120 and LMRP 140 are configured to controllably seal wellbore 101 and contain hydrocarbon fluids therein. Specifically, BOP 120 has a central or longitudinal axis 125 and includes a body 123 with an upper end 123a releasably secured to LMRP 140, a lower end 123b releasably secured to wellhead 130, and a main bore 124 extending axially between upper and lower ends 123a, b. Main bore 124 is coaxially aligned with wellbore 101, thereby allowing fluid communication between wellbore 101 and main bore 124. In this embodiment, BOP 120 is releasably coupled to LMRP 140 and wellhead 130 with hydraulically actuated, mechanical wellhead-type connections 150. In general, connections 150 may comprise any suitable releasable wellhead-type mechanical connection such as the H-4® profile subsea system available from VetcoGray Inc. of Houston, Tex., the DWHC profile subsea system available from Cameron International Corporation of Houston, Tex., and the HC profile subsea system available from FMC Technologies of Houston, Tex. Typically, such wellhead-type mechanical connections (e.g., connections 150) comprise an upward-facing male connector or “hub,” labeled with reference numeral 150a herein, that is received by and releasably engages a complementary, downward-facing mating female connector or receptacle, labeled with reference numeral 150b herein. In addition, BOP 120 includes a plurality of axially stacked sets of opposed rams—one set of opposed blind shear rams or blades 127 for severing tubular string 116 and sealing off wellbore 101 from riser 115 and two sets of opposed pipe rams 128, 129 for engaging string 116 and sealing the annulus around tubular string 116. In other embodiments, the BOP (e.g., 120) may also include one or more sets of opposed blind rams for sealing off wellbore when no string (e.g., string 116) or tubular extends through the main bore of the BOP (e.g., main bore 124). Each set of rams 127, 128, 129 is equipped with sealing members that engage to prohibit flow through the annulus around string 116 and/or main bore 124 when rams 127, 128, 129 is closed.
Opposed rams 127, 128, 129 are disposed in cavities that intersect main bore 124 and support rams 127, 128, 129 as they move into and out of main bore 124. Each set of rams 127, 128, 129 is actuated and transitioned between an open position and a closed position. In the open positions, rams 127, 128, 129 are radially withdrawn from main bore 124 and do not interfere with tubular string 116 or other hardware that may extend through main bore 124. However, in the closed positions, rams 127, 128, 129 are radially advanced into main bore 124 to close off and seal main bore 124 (e.g., rams 127) or the annulus around tubular string 116 (e.g., rams 128, 129). Each set of rams 127, 128, 129 is actuated and transitioned between the open and closed positions by a pair of actuators 126. In particular, each actuator 126 hydraulically moves a piston within a cylinder to move a drive rod coupled to one ram 127, 128, 129.
Referring still to
Referring now to
As previously described, in this embodiment, BOP 120 includes three sets of rams (one set of shear rams 127 and two sets of pipe rams 128, 129), however, in other embodiments, the BOP (e.g., BOP 120) may include a different number of rams (e.g., four sets of rams), different types of rams (e.g., two sets of shear rams and two sets of pipe rams, one or more sets of opposed blind rams), an annular BOP (e.g., annular BOP 142a), or combinations thereof. It should be appreciated that BOP 120 is exemplary only and that any subsea BOP preferably includes at least three sets of rams including at least two sets of pipe rams and at least one set of blind-shear rams. Likewise, although LMRP 140 is shown and described as including one annular BOP 142a, in other embodiments, the LMRP (e.g., LMRP 140) may include a different number of annular BOPs (e.g., two sets of annular BOPs), different types of rams (e.g., shear rams), or combinations thereof.
Referring now to
Referring now to
In this embodiment, each assembly 210, 250, 290 is sized and configured to be air-freightable on its own or in conjunction with another assembly 210, 250, 290. In other words, each assembly 210, 250, 290 has a weight and dimensions suitable for air transport. Conventional cargo aircraft such as the Antonov AN124 and Boeing 747 have a maximum payload capacity of about 120 tons (240×103 lbs.), and cargo bays sized to accommodate cargo having a maximum width of up to about 21 ft. and a maximum height of up to about 14 ft. In embodiments described herein, lower assembly 210 has a weight of about 70 tons (140×103 lbs.), upper assembly 250 has a weight of about 40 tons (80×103 lbs.), and kill-flowback assembly 290 has a weight of about 7.5 tons (15×103 lbs.). In addition, each assembly 210, 250, 290 is sized such that it can be oriented to have a width less than 21 ft. and a height less than 14 ft. For example, although upper assembly 250 may have a height greater than 14 ft., it is dimensioned such that it can be laid down and fit within the confines of the cargo bay during shipment and then erected after transport for deployment. Accordingly, any two of the three assemblies 210, 250, 290 may be transported together by air in a single cargo aircraft. The assembly 210, 250, 290 not transported with another assembly 210, 250, 290 may be transported in a separate cargo aircraft. As previously described, conventional capping stacks are not sized and configured to be transported by air because their weight exceeds the payload capacity of conventional cargo aircraft and/or their dimensions cannot be accommodated by conventional cargo aircraft cargo bays. Consequently, transport of such conventional capping stacks must be accomplished by land and/or sea vessel, which, depending on the relative locations of the offshore blowout and the capping stack, may be time consuming. For example, if there is a subsea blowout in the Gulf of Mexico, and the most suitable capping stack for containing that blowout is located in the Middle East, it may take days or even weeks to transport the capping stack by land and sea to the offshore location in the Gulf of Mexico. However, embodiments of containment caps described herein (e.g., cap 200) are air-freightable, and thus, may be transported around the globe in a matter of hours or short number of days (e.g., one to two days maximum). As a result, embodiments described herein offer the potential to more efficiently and timely contain a subsea blowout, thereby reducing the total volume of subsea hydrocarbon emissions.
Referring now to
Spool body 221 includes a first pipe spool or spool piece 222 and a second pipe spool or spool piece 230 attached to and extending perpendicularly from spool piece 222. Spool piece 222 has a central or longitudinal axis 223, a first or upper end 222a, a second or lower end 222b opposite end 222a, a vertical flow bore or throughbore 224 extending axially between ends 222a, b, and a horizontal flow bore 225 extending perpendicularly from bore 224. Upper end 222a of first spool piece 222 defines the upper end of spool body 221, and lower end 222b of first spool piece 222 defines the lower end of spool body 221. Throughbore 224 is coaxially disposed within spool piece 222. In other words, throughbore 224 has a central axis coincident with axis 223. Throughbore 224 has a minimum inner diameter equal to or greater than the inner diameter of wellbore 101, through bore 142, and main bore 124, and thus, throughbore 224 may be described as having a “full bore diameter” and providing “full bore access.”
Upper end 222a of spool piece 222 comprises an upward-facing hub 150a and lower end 222b comprises a downward-facing receptacle 150b. Hub 150a at upper end 222a extends axially upward from frame 211 and is configured to mate, engage, and interlock with a downward-facing complementary connector 150b on upper assembly 250, thereby forming a releasable wellhead-type, hydraulically actuated mechanical connection 150 between assemblies 210, 250. As will be described in more detail below, receptacle 150b at lower end 222b is configured to mate, engage, and interlock with an upward-facing complementary hub 150a on a transition spool 330, BOP 120, or wellhead 130, thereby forming a releasable wellhead-type, hydraulically actuated mechanical connection 150 between lower assembly 210 and flex joint adapter 145, BOP 120, or wellhead 130, respectively.
Referring still to
Throughbore 232 is coaxially aligned with and contiguous with horizontal bore 225. Thus, throughbore 232 is in fluid communication with bore 225. Together, bores 225, 232 define a horizontal branch or flow path in spool body 221 that extends perpendicularly from vertical main bore 224. As best shown in
Lower assembly 210 also includes a choke valve 234 positioned between a fluid conduit 235 and spool piece 230. Fluid conduit 235 has a first end 235a coupled to choke valve 234, a second end 235b distal choke valve 234, and a flow bore 236 extending between ends 235a, b. Ends 230b, 235a are coupled to choke valve 234, and bores 232, 236 are in fluid communication with choke valve 234. Thus, choke valve 234 controls the flow rate of fluids between bores 232, 236. In general, choke valve 234 may comprise any suitable choke or choke valve for regulating the rate of fluid flow between bores 232, 236. In this embodiment, choke valve 234 is a Willis CC40 Control Choke with SLCA Hydraulic Stepping Actuator capability (non-functional) or mechanical stepping capability with torque tool available from Cameron International Corporation of Houston, Tex. The choke valve 234 has a retrievable insert that can be removed and replaced subsea.
Second end 235b of fluid conduit 235 comprises an upward-facing hub 239a configured to mate, engage, and interlock with a downward-facing connector of a flow line to form a releasable flow line connection therebetween. Thus, with each valve 233 open, fluid in throughbore 224 is free to flow through bores 225, 232, choke valve 234, and bore 236 to hub 239a at end 235b, where the fluid may be discharged into the surrounding sea or flowed into another device connected to hub 239a at end 235b. For example, as will be described in more detail below, when lower assembly 210 is coupled to wellbore 101 and each valve 233 is open, hydrocarbons discharged from wellbore 101 may be flowed from bore 224 through bores 225, 232, choke valve 234, and bore 236 to hub 239a at end 235b, where the hydrocarbons may be discharged into the surrounding sea or produced to another device connected to hub 239a at end 235b. Alternatively, with each valve 233 open, fluid may be supplied and/or pumped from a device connected to hub 239a through bore 236, choke valve 234, and bores 232, 225 into bore 224. For example, as will be described in more detail below, when lower assembly 210 is coupled to wellbore 101, chemicals or kill weight fluids may be supplied and/or pumped from a device connected to hub 239a through bore 236, choke valve 234, and bores 232, 225 into hydrocarbons in bore 224.
As best shown in
Referring still to
Each flow line 241, 242, 243 includes a primary valve 245 for controlling the flow of chemicals through that particular flow line 241, 242, 243. Namely, each valve 245 has an open position allowing fluid flow therethrough and a closed position restricting and/or preventing fluid flow therethrough. Consequently, fluid flow through a particular flow line 241, 242, 243 is restricted and/or prevented if its corresponding valve 245 is closed, and fluid flow through a particular flow line 241, 242, 243 is permitted if its corresponding valve 245 is opened. In general, each valve 245 may comprise any type of valve suitable for the anticipated fluid pressures and fluids in flow lines 241, 242, 243 including, without limitation, ball valves, gate valves, and butterfly valves. Further, each valve 245 may be manually actuated, hydraulically actuated, mechanically actuated, or electrically actuated valves. In this embodiment, each valve 245 is a hydraulically actuated gate valve rated for a 15 k psi pressure differential. Each valve 245 may be controlled and hydraulically actuated subsea with an ROV. In addition, in this embodiment, valve 245 on each flow line 242, 243 includes a check valve that allows one-way fluid communication from inlet receptacle 248 to bore 224. Valve 245 on flow line 241 does not include a check valve so that pressure testing and sampling of bore 232 may be performed. Each flow line 242, 243 also includes a pressure gauge 246 positioned between valve 245 and its inlet receptacle 248. Gauges 246 measure the fluid pressure within flow lines 242, 243. Secondary valves 247 are positioned along flow lines 242, 243 between gauges 246 and inlet receptacle 248, and an additional secondary valve 247 is positioned at inlet receptacle 248. Secondary valves 247 provide a secondary means to valves 245 for controlling fluid flow through flow lines 241, 242, 243. In general, each valve 247 may comprise any type of valve suitable for the anticipated fluid pressures and fluids in flow lines 241, 242, 243 including, without limitation, ball valves, gate valves, and butterfly valves. Further, each valve 247 may be manually actuated, hydraulically actuated, mechanically actuated, or electrically actuated valves. In this embodiment, each valve 247 is a manually operated needle valve rated for a 15 k psi pressure differential. Each valve 247 may be manually operated subsea with an ROV. Alternatively, each valve 247 may be hydraulically controlled from the surface with hydraulic flow lines or flying leads extending from the surface and coupled to valves 247 via a panel located on lower assembly 210.
Referring still to
Referring now to
Spool piece 260 has a central or longitudinal axis 261, a first or upper end 260a, a second or lower end 260b opposite end 260a, and a flow bore or throughbore 262 extending axially between ends 260a, b. Flow bore 262 is coaxially disposed within spool piece 260. In other words, flow bore 262 has a central axis coincident with axis 261. In this embodiment, spool piece 260 is oriented such that axis 261 and flow bore 262 extend vertically. In addition, in this embodiment, flow bore 262 has a minimum inner diameter that is less than the minimum inner diameter of throughbore 224 and wellbore 101.
Upper end 260a of spool piece 260 comprises an upward-facing hub 150a and lower end 260b comprises a downward-facing receptacle 150b. Hub 150a at upper end 260a extends axially upward from pad 252 and is configured to mate, engage, and interlock with a complementary downward-facing connector 150b on assembly 290, thereby forming a releasable wellhead-type, hydraulically actuated mechanical connection 150 between assemblies 250, 290. Further, receptacle 150b at lower end 260b is configured to mate, engage, and interlock with a complementary upward-facing hub 150a at upper end 222a of spool piece 221, thereby forming a releasable wellhead-type, hydraulically actuated mechanical connection 150 between assemblies 210, 250.
As best shown in
Referring now to
Each flow line 271, 272 includes a pair of valves 273, arranged series, for controlling the flow of chemicals through that particular flow line 271, 272. Namely, each valve 273 has an open position allowing fluid flow therethrough and a closed position restricting and/or preventing fluid flow therethrough. Consequently, fluid flow through a particular flow line 271, 272 is restricted and/or prevented if one or both of its valves 273 is closed, and fluid flow through a particular flow line 271, 272 is permitted if both of its corresponding valves 273 are opened. In general, each valve 273 may comprise any type of valve suitable for the anticipated fluid pressures and fluids in flow lines 271, 272 including, without limitation, ball valves, gate valves, and butterfly valves. Further, each valve 273 may be manually actuated, hydraulically actuated, mechanically actuated, or electrically actuated valves. In this embodiment, each valve 273 is a manually operated needle valve rated for a 15 k psi differential. Each valve 273 may be manually operated subsea with an ROV. In this embodiment, return line 272 includes a pressure gauge 246 positioned between valves 273 and access member 265. Gauge 246 measure the fluid pressure within return line 272.
Referring still to
In this embodiment, systems 270, 280 utilize separate supply and return lines. Namely, system 270 includes supply line 271 and return line 272, and system 280 includes supply line 281 and return line 282. However, in other embodiments, the fluid monitoring system (e.g., system 280) may utilize the same supply and return lines as the chemical injection system (e.g., system 270). For example, sensor package 285 may be configured to plug into hot stab receptacle 248, receive wellbore fluids via supply line 271 and return wellbore fluids via return line 272. In other words, ends 286a, b of flow line 286 may be configured as ports in a hot stab connector that is coupled to receptacle 248 with inlet end 286a in fluid communication with supply line 271 and outlet end 286b in fluid communication with return line 272.
Referring now to
Spool piece 292 has a central or longitudinal axis 294, a first or upper end 292a, a second or lower end 292b opposite end 292a, and a flow bore or throughbore 295 extending axially between ends 292a, b. Flow bore 295 is coaxially disposed within spool piece 292. In other words, flow bore 295 has a central axis coincident with axis 294. In this embodiment, spool piece 292 is oriented such that axis 294 and flow bore 295 extend vertically. In this embodiment, flow bore 295 has an inner diameter that is the same as the inner diameter of flow bore 262.
Upper end 292a of spool piece 292 extends axially upward from frame 291 and comprises an upward-facing flange 296, and lower end 292b comprises a downward-facing receptacle 150b. Flange 296 is configured to mate, engage, and connect with a downward-facing flange on a flow conduit that supplies kill weight fluids to cap 200 and/or produces hydrocarbons from wellbore 101. In this embodiment, two exemplary conduits 298, 299 are shown in
Referring again to
In this embodiment, containment cap 200 is designed to be deployed subsea and landed on riser flex joint 143 of LMRP 140, on mandrel 151 of LMRP 140, on BOP 120, or on wellhead 130, depending on which is the most suitable landing site. For example, in
Referring briefly to
Referring now to
For subsea deployment and installation of containment cap 200, one or more remote operated vehicles (ROVs) are preferably employed to aid in positioning assemblies 210, 250, 290, monitoring assemblies 210, 250, 290 and BOP 120, and operating assemblies 210, 250, 290 (e.g., actuating valves 233, 263, operating chemical injection systems, etc.). In this embodiment, three ROVs 170 are employed to position assemblies 210, 250, 290, monitor assemblies 210, 250, 290 and BOP 120, and operate assemblies 210, 250, 290. Each ROV 170 includes an arm 171 having a claw 172, a subsea camera 173 for viewing the subsea operations (e.g., the relative positions of assemblies 210, 250, 290, BOP 120, plume 160, the positions and movement of arms 170 and claws 172, etc.), and an umbilical 174. Streaming video and/or images from cameras 173 are communicated to the surface or other remote location via umbilical 174 for viewing on a live or periodic basis. Arms 171 and claws 172 are controlled via commands sent from the surface or other remote location to ROV 170 through umbilical 174.
Before connecting cap 200 to BOP 120, LMRP 140 is removed from BOP 120 by decoupling connection 150 between BOP 120 and LMRP 140, and then lifting LMRP 140 from BOP 120 with wireline, a pipestring, one or more ROVs 170, or combinations thereof. In addition, any tubulars or debris extending from upper end 123a of BOP 120 are cut off substantially flush with upper end 123a with one or more ROVs 170.
Referring first to
Moving now to
Moving now to
As assembly 210 is positioned immediately above BOP 120, hydrocarbons emitted from BOP 120 are free to flow unrestricted through bore 224. In addition, prior to moving assembly 210 laterally over BOP 120, valves 233 in lines 237, 238 are closed, and valves 233 in bores 225, 232 are opened to allow hydrocarbon fluids emitted by BOP 120 to flow through bore 232, choke 234, and bore 236. Valves 233 in bores 225, 232 may be transitioned to the open position and valves 233 in lines 237, 238 may be transitioned to the closed position at the surface 102 prior to deployment, or subsea via one or more ROVs 170. Thus, as assembly 210 is moved laterally over BOP 120 and lowered into engagement with BOP 120, emitted hydrocarbon fluids flow freely through bores 224, 225, 232, 236. As a result, open valves 233 offer the potential to reduce the resistance to the axial insertion of hub 150a into receptacle 150b and coupling of lower assembly 210 to BOP 120. In other words, open valves 233 in bores 225, 232 allow the relief of well pressure during installation of lower assembly 210. With a sealed, secure connection between lower assembly 210 and BOP 120, ROVs 170 decouple running tool 215 from lower assembly 210. Running tool 215 and adapter 216 may then be removed to the surface with pipestring 180.
Referring now to
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Prior to moving upper assembly 250 laterally over lower assembly 210 and BOP 120, valves 263 are transitioned to the open position also allowing hydrocarbon fluids emitted by BOP 120 and lower assembly 210 to flow through bore 262. Valves 263 may be transitioned to the open position at the surface 102 prior to deployment, or subsea via one or more ROVs 170. Thus, as upper assembly 250 is moved laterally over lower assembly 210 and lowered into engagement with lower assembly 210, emitted hydrocarbon fluids flow freely through bore 262. As a result, open valves 263 offer the potential to reduce the resistance to the axial insertion of hub 150a into receptacle 150b and coupling of upper assembly 250 to lower assembly 210. In other words, open valves 263 allow the relief of well pressure during installation of upper assembly 250. It should also be appreciated that aligned bores 224, 262 enable re-entry of BOP 120 and wellbore 101.
Referring now to
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Prior to moving assembly 290 laterally over upper assembly 250 and BOP 120, flow bore 295 is maintained opened to allow hydrocarbon fluids emitted by BOP 120 and assemblies 210, 250 to flow through bore 295. Thus, as kill-flowback assembly 290 is moved laterally over upper assembly 250 and lowered into engagement with upper assembly 250, emitted hydrocarbon fluids flow freely through bore 295, thereby offering the potential to reduce the resistance to the axial insertion of hub 150a into receptacle 150b and coupling of assembly 290 to upper assembly 250. In other words, open flow bore 295 allows the relief of well pressure during installation of kill-flowback assembly 290. A conduit 298, 299 may be coupled to upper end 292a of spool piece 292 (to supply kill weight fluids or produce wellbore 101) once assembly 290 is securely connected to upper assembly 250.
In the manner described, cap 200 is deployed and installed on BOP 120. However, as best shown in
Referring now to
To shut-in wellbore 101, valves 233 in flow lines 237, 238 are both closed, and valves 233 in bores 225, 232 are both maintained opened while upper valve 263 is transitioned closed. As upper valve 263 is transitioned closed, the pressure of wellbore fluids within lower assembly 210 are monitored with pressure transducer 227 and the pressure of wellbore fluids within upper assembly 250 are monitored with pressure sensor 287. As long as the formation fluid pressures within assemblies 210, 250 are within acceptable limits, upper valve 263 continues to be closed until it is fully closed. Once upper valve 263 is closed, lower valve 263 may also be fully closed to provide redundancy. With both valves 263 closed, fluid flow through bore 262 is restricted and/or prevented, however, since valves 233 in bores 225, 232 are opened, formation fluids are free to flow through bores 224, 225, 232, 236 and choke valve 234. Next, valve 233 in bore 232 is transitioned closed. As that valve 233 is transitioned closed, the pressure of wellbore fluids within lower assembly 210 are monitored with pressure transducer 227. As long as the formation fluid pressures within assembly 210 is within acceptable limits, valve 233 in bore 232 continues to be closed until it is fully closed. Once valve 233 in bore 232 is closed, valve 233 in bore 225 may also be fully closed to provide redundancy. With each valve 233, 263 closed, wellbore 101 is contained and shut-in. It should be appreciated that inclusion of choke valve 234 and the staged shut-in of wellbore 101 via sequential closure of valves 233, 263 enables a “soft” shut-in, thereby offering the potential to reduce the likelihood of an abrupt formation pressure surge, which may damage subsea components (e.g., BOP 120, assembly 210, assembly 250, assembly 290) and lead to another subsea blowout.
Once wellbore 101 is shut-in and generally under control, and the necessary infrastructure for producing wellbore 101 are in place (e.g., hydrocarbon storage vessels, risers, manifolds, flow lines, etc. are installed), wellbore 101 may be produced via kill-flowback assembly 290 and/or conduit 235. For example, depending on the particular circumstances, wellbore 101 may be produced through flowback assembly 290 with valves 233 closed and valves 263 opened, produced through conduit 235 with valves 233 opened and valves 263 closed, or produced through both assembly 290 and conduit 235 with all valves 233, 263 opened.
As previously described, lower assembly 210 includes chemical injection system 240, and upper assembly 250 includes a chemical injection system 270. Injection systems 240, 270 may be used prior to, during, or after shutting-in wellbore 101 to inject chemicals into bores 224, 262, respectively, and wellbore 101. For example, chemicals such as glycol and/or methanol may be injected to reduce hydrate formations within assemblies 210, 250 which might otherwise hamper or prevent the ability to install assemblies 210, 250. As another example, chemical dispersants may be injected into hydrocarbons flowing through assemblies 210, 250 after installation to mitigate volume of oil and volatile organic compounds generated at the sea surface.
Containment cap 200 previously described may also be installed onto mandrel 151 or flex joint 143 of LMRP 140. Installation of cap 200 onto flex joint 143 of LMRP 140 will now be described. As shown in
Referring to
Referring still to
Mule shoe 340 is a tubular extending axially downward from flange 334. In this embodiment, shoe 340 also includes a plurality of circumferentially spaced elongate through slots 343 extending radially from the outer cylindrical surface of shoe 340 to bore 331. In the embodiment, slots 343 are oriented parallel to axis 335. In other embodiments, the slots in the mule shoe (e.g., slots 343 in mule shoe 340) may be omitted. Moreover, although this embodiment of transition spool 330 includes mule shoe 340, in other embodiments, the mule shoe (e.g., mule shoe 340) is completely eliminated. In such embodiments, a plurality of guide pins (e.g., guide pins 338) facilitate the alignment and coupling of the transition spool (e.g., spool 320) and the flex joint (e.g., flex joint 143)
As will be described in more detail below, during installation of transition spool 330 onto flex joint 143, mule shoe 340 is coaxially aligned with joint 143 and axially advanced into joint 143 until flanges 145a, 334 axially abut. During insertion of mule shoe 340 into flex joint 143, through slots 343 provide a flow path for hydrocarbon fluids discharged from wellbore 101 through BOP 120 and LMRP 140, thereby offering the potential to relieve wellbore pressure during installation.
To facilitate the alignment and insertion of mule shoe 340 into flex joint 143, lower end 330b is angled or tapered in side view (i.e., when viewed perpendicular to axis 335). Specifically, lower end 330b is oriented at an angle β relative to axis 335. Angle β is preferably between 30° and 60°. In this embodiment, angle β is 45°. Tapered lower end 330b also facilitates the axial advancement of mule shoe 340 into another component (e.g., flex joint 143) that is bent or angled relative to vertical and/or that contain pipes or tubulars disposed therein. For example, mule shoe 340 may be inserted into another component and slowly axially advanced. As shoe 340 is advanced, tapered end 330b slidingly engages the component, thereby guiding shoe 340 into the component. In addition, tapered end 330b slidingly engages and guides tubulars within the component into bore 331. In other words, tapered end 330b enables mule shoe 340 to wedge itself radially between the component and the tubulars disposed therein. This may be particularly advantageous in instances where mule shoe 340 is coupled to a component that contains damage tubulars or pipes that cannot be removed.
To prepare flange 145a for sealing engagement with flange 334, riser 115 is removed from flex joint 143, and any tubulars or debris extending upward from flange 145a are preferably cut off substantially flush with flange 145a. In addition, riser adapter 145 is preferably oriented vertically and locked in the vertical position prior to coupling transition spool 330, lower assembly 210, upper assembly 250, kill-flowback assembly 290, or combinations thereof to riser adapter 145. This offers the potential to simplify installation of these components as well as reduce moments experienced by adapter 145 following installation of these components. More specifically, since riser adapter 145 is designed to angularly deflect and pivot relative to base 144, the moments exerted on riser adapter 145 following attachment of such components may cause riser adapter 145 to undesirably pivot and/or break. However, by straightening flex joint 143 (i.e., orienting riser adapter 145 vertically) and locking riser adapter 145 in place, such moments can be reduced and resisted without adapter 145 pivoting or breaking. In general, riser adapter 145 may be oriented vertically and locked in the vertical orientation by any suitable systems and/or methods. Examples of suitable systems and methods for orienting riser adapter 145 vertically and locking riser adapter 145 in the vertical orientation are disclosed in U.S. patent application No. 61/482,132 filed May 3, 2011, and entitled “Adjustment and Restraint System for a Subsea Flex Joint,” which is hereby incorporated herein by reference in its entirety for all purposes.
Referring briefly to
Each hydraulic cylinder assembly 310 includes a cylinder member 311 that rests in the upper pocket 302 and a piston member 312 extending from cylinder member 311. Piston member 312 is hydraulically actuated to extend or retract relative to cylinder member 311. Piston member 312 includes a contact member 313 for engaging the outer surface of riser adapter 145. Upon actuation, piston member 312 can be extended axially from cylinder member 311 to exert a radial force on riser adapter 145 to pivot riser adapter 145 to the vertical position. In general, hydraulic cylinder assembly 310 may be any one of several robustly rated cylinders, including, for example, Enerpac® RC-502 hydraulic cylinders and/or Enerpac® RC-504 hydraulic cylinders which have an approximately 50-ton cylinder capacity. Hydraulic cylinders with various other capacities and characteristics are also contemplated and known to one having ordinary skill.
Base members 301 and cylinder assemblies 310 are positioned about riser adapter 145 with one or more subsea ROVs (e.g., ROVs 170). In particular, base members 301 and cylinder assemblies 310 are circumferentially positioned and spaced to exert the appropriate radial forces on riser adapter 145 to vertically orient riser adapter 145.
Referring now to
Referring now to
To adjust the angle between riser adapter 145 and base 144, caps 341 are mounted on the studs extending upward from base 144, and one or more assemblies 345 are circumferentially disposed about riser adapter 145. In particular, assemblies 345 are radially positioned between caps 341 and riser adapter 145 with housing 346a engaging caps 341, piston member 348 extending radially inward from housing 346a towards riser adapter 145, and flange 346b engaging the inner surface of base 144. Next, assemblies 347 are actuated to extend piston members 348 radially inward into engagement riser adapter 145. Continued actuation of assemblies 347 causes piston members 348 to exert a radial force on riser adapter 145 to pivot riser adapter 145 to the desired vertical position. In general, hydraulic cylinder assembly 345 may be any one of several robustly rated cylinders, including, for example, Enerpac® RC-502 hydraulic cylinders and/or Enerpac® RC-504 hydraulic cylinders which have an approximately 50-ton cylinder capacity. Hydraulic cylinders with various other capacities and characteristics are also contemplated and known to one having ordinary skill.
Caps 341 and cylinder assemblies 345 are positioned about riser adapter 145 with one or more subsea ROVs (e.g., ROVs 170). In particular, caps 341 and cylinder assemblies 345 are circumferentially positioned and spaced to exert the appropriate radial forces on riser adapter 145 to vertically orient riser adapter 145.
Once adapter 145 is oriented vertically, it is preferably locked in the vertical orientation so that it does not bend or flex during or after installation of a containment cap. For example, systems 300, 340 can be uniformly circumferentially disposed about riser adapter 145 to exert balanced radial forces that maintain riser adapter 145 in the vertical orientation. Alternatively, rigid wedges may be disposed in the annulus radially positioned between riser adapter 145 and base 144, and uniformly circumferentially spaced about riser adapter 145 once adapter 145 is vertically oriented to maintain adapter 145 in the vertical orientation.
Referring now to
As best shown in
Referring now to
Referring first to
Moving now to
Due to its own weight, spool 330 is substantially vertical, whereas riser adapter 145 may be oriented at an angle relative to vertical. Thus, it is to be understood that perfect coaxial alignment of mule shoe 340 and flex joint 143, as well as perfect alignment of pins 338 and mating holes in flange 145a, may be difficult.
With mule shoe 340 positioned immediately above and generally coaxially aligned with riser adapter 145, and guide pins 338 aligned with corresponding holes in flange 145a, wireline 181 lower spool 330 axially downward, thereby inserting and axially advancing pins 338 into corresponding holes 148 and inserting and axially advancing mule shoe lower end 330b into riser adapter 145 until flange 334 axially abuts and engages flange 145a as shown in
With mule shoe 340 sufficiently seated in riser adapter 145 and flange 334 abutting mating flange 145a, holes 334a are coaxially aligned with corresponding holes 147 in flange 145a and plug 337 is disposed in mud boost outlet 149b. Next, one ROV 170 cuts band 336, thereby allowing bolts 334b to drop into holes 147. One or more ROVs 170 may also help facilitate the lowering of bolts 334b into holes 147 if necessary. Bolts 334b may then be tightened with ROVs 170 to rigidly secure spool 330 to riser adapter 145. With a sealed, secure connection between spool 330 and riser adapter 145, ROVs 170 decouple leads 253 from transition spool 330. Leads 253 may then be removed to the surface with wireline 181.
Once transition spool 330 is securely coupled to riser adapter 145, assemblies 210, 250, 290 are deployed in the same manner as previously described with respect to
Once wellbore 101 is shut-in and generally under control, and the necessary infrastructure for producing wellbore 101 are in place (e.g., hydrocarbon storage vessels, risers, manifolds, flow lines, etc. are installed), wellbore 101 may be produced via flowback assembly 290 and/or conduit 235. In addition, injection systems 240, 270 may be used prior to, during, or after shutting-in wellbore 101 to inject chemicals into bores 224, 262, respectively, and wellbore 101. Although
Referring now to
As previously described, lower assembly 210 is air-freightable. In this embodiment, valve assembly 450, cap 470, and coupling 480 are also air-freightable. Thus, lower assembly 210, valve assembly 450, cap 470, and coupling 480 are each sized and configured to be transported by air on its own or with one or more of assembly 210, assembly 450, cap 470, and coupling 480. In other words, lower assembly 210, valve assembly 450, cap 470, and coupling 480 each has a weight and dimensions suitable for air transport. In this embodiment, valve assembly 450 has a weight under 30 tons, and thus, may be transported along with lower assembly 210.
Referring still to
Valve assembly 450 is partially disposed within main bore 224—upper end 451a extends axially from bore 224, and lower end 451b is disposed in bore 224. An annular insert 460 is coaxially disposed within bore 224 axially between assembly 450 and an annular shoulder 224a within bore 224. Insert 460 has a first or upper end 460a, a second or lower end 460b opposite end 460a, and a flow passage 461 extending axially between ends 460a, b. Upper end 460a comprises a cylindrical recess or counterbore 462 that receives lower end 451b, and lower end 460b comprises a reduced outer diameter portion that extends into bore 224 below shoulder 224a. Thus, insert 460 is seated in bore 224 against shoulder 224a, and tubular body 451 is seated in recess 462. A plurality of annular seal assemblies 470 are radially disposed between tubular body 451 and spool piece 222. Seal assemblies 470 restrict and/or prevent fluids from flowing axially between body 451 and spool piece 222.
Referring still to
Containment cap 400 is deployed subsea and installed on wellhead 130, BOP 120, or LMRP 140 to contain and shut-in wellbore 101, and/or produce wellbore 101. To simplify deployment, containment cap 400 is preferably deployed and installed subsea as a single unit in a single trip. In other words, in this embodiment, valve assembly 450 is preferably installed in lower assembly 210, and cap 470 coupled to lower assembly 210 with coupling 480 at the surface 102, and then the entire pre-assembled cap 400 lowered subsea. To install cap 400 onto BOP 120, riser 115 is removed from LMRP 140, and LMRP 140 is removed from BOP 120. Then, cap 400 is lowered subsea on a pipestring 180 or wireline 181 coupled to hub 239a, and securely attached to BOP 120 with wellhead-type connection 150. To install cap 400 onto wellhead 130, riser 115 is removed from LMRP 140, LMRP 140 is removed from BOP 120, and BOP 120 is removed from wellhead 130. Then, cap 400 is lowered subsea on a pipestring 180 or wireline 181 coupled to hub 239a, and securely attached to wellhead 130 with wellhead-type connection 150. To install cap 400 onto LMRP 140, riser 115 is removed from LMRP 140, then transition spool 330 is lower subsea and securely attached to riser adapter 145 as previously described. Next, cap 400 is lowered subsea and securely attached to transition spool 330 with wellhead-type connection 150. In each case, cap 400 is preferably lowered subsea laterally offset from wellbore 101 and outside of plume 160, and then moved laterally over the landing site (e.g., BOP 120, transition spool 330, or wellhead 130) and coupled thereto with a wellhead type-connection 150. One or more ROVs 170 may be employed to facilitate the installment of cap 400.
Although cap 400 is preferably assembled at the surface 102, and then lowered subsea as a single unit, in other embodiments, lower assembly 210 and valve assembly 450 may be lowered subsea separately, and then assembled into cap 400 subsea. For instance, lower assembly 210 may be lowered subsea and installed on wellhead 130, BOP 120, or transition spool 330 as previously described, and then valve assembly 450 may be lowered subsea with wireline 181 or pipestring 180, installed in bore 224, and secured to assembly 210 with cap 470 and annular coupling 480.
Referring still to
To shut-in wellbore 101, valves 233 in flow lines 237, 238 are both closed, and valves 233 in bores 225, 232 are both maintained opened while upper valve 454 is transitioned closed. As upper valve 454 is transitioned closed, the pressure of wellbore fluids within lower assembly 210 are monitored with pressure transducer 226 and the pressure of wellbore fluids within upper assembly 250 are monitored with pressure sensor 287. As long as the formation fluid pressures within assemblies 210, 450 are within acceptable limits, upper valve 454 continues to be closed until it is fully closed. Once upper valve 454 is closed, lower valve 454 may also be fully closed to provide redundancy. With both valves 454 closed, fluid flow through bore 453 is restricted and/or prevented, however, since valves 233 in bores 225, 232 are opened, formation fluids are free to flow through bores 224, 225, 232, 236 and choke valve 234. Next, valve 233 in bore 232 is transitioned closed. As that valve 233 is transitioned closed, the pressure of wellbore fluids within lower assembly 210 are monitored with pressure transducer 226. As long as the formation fluid pressures within assembly 210 is within acceptable limits, valve 233 in bore 232 continues to be closed until it is fully closed. Once valve 233 in bore 232 is closed, valve 233 in bore 225 may also be fully closed to provide redundancy. With each valve 233, 454 closed, wellbore 101 is contained and shut-in. Accordingly, in this embodiment, valves 454 of assembly 450 perform the same function(s) as valves 263 of upper assembly 250 previously described. It should be appreciated that inclusion of choke valve 234 and the staged shut-in of wellbore 101 via sequential closure of valves 233, 454 enables a “soft” shut-in, thereby offering the potential to reduce the likelihood of an abrupt formation pressure surge, which may damage subsea components (e.g., BOP 120, assembly 210, assembly 450, assembly 290) and lead to another subsea blowout.
Once wellbore 101 is shut-in and generally under control, and the necessary infrastructure for producing wellbore 101 are in place (e.g., hydrocarbon storage vessels, risers, manifolds, flow lines, etc. are installed), wellbore 101 may be produced via hub 239a at upper end 470a of cap 470 and/or conduit 235. For example, depending on the particular circumstances, wellbore 101 may be produced through cap 470 with valves 233 closed and valves 454 opened, produced through conduit 235 with valves 233 opened and valves 454 closed, or produced through both cap 470 and conduit 235 with all valves 233, 454 opened.
As previously described, lower assembly 210 includes chemical injection system 240. Injection systems 240 may be used prior to, during, or after shutting-in wellbore 101 to inject chemicals into bores 224, 453, respectively, and wellbore 101. For example, chemicals such as glycol may be injected to reduce hydrate formations within assemblies 210, 450.
In the manner described, embodiments of containment caps described herein (e.g., caps 200, 400) may be deployed subsea from a surface vessel and installed on a subsea wellhead (e.g., wellhead 130), BOP (e.g., BOP 120) or LMRP (e.g., LMRP 140) that is emitting hydrocarbon fluids into the surrounding sea. Once securely installed subsea, a series of valves are actuated and closed to achieve a “soft” shut-in of the wellbore. Pressure and temperature sensors are included to measure the pressure and temperature of the wellbore fluids, thereby enabling an operator to manage the opening and closing of valves in a manner that reduces the likelihood of a blowout while attempting to shut-in the wellbore. For example, while shutting in the wellbore, the valves are preferably closed in a sequential order while the wellbore pressure is continuously monitored. In the event closure of a particular valve triggers an undesirable increase in wellbore pressure, that valve (or another valve) may be immediately opened to relieve the increased wellbore pressure, thereby offering the potential to avert a blowout while shutting in the well. Likewise, after the well is shut-in, the wellbore pressure may be monitored so that a valve may be opened in the event of an unexpected spike in wellbore pressure to relieve such wellbore pressure increase.
Referring now to
If the selected landing site is mandrel 151 of LMRP 140 or riser adapter 145, the connection between riser 115 and riser adapter 145 is broken, and riser 115 is removed from riser adapter 145 according to block 506. If the selected landing site is riser adapter 145, then the appropriate transition spool (e.g., transition spool 330), as needed, is deployed and installed subsea according to block 510. However, if the landing site is LMRP mandrel 151, then flex joint 143 (including riser adapter 145) is removed at block 535. Thereafter, appropriate transition spool (e.g., transition spool 330), as needed, is deployed and installed subsea on mandrel 151 at block 536. On the other hand, if the selected landing site is BOP 120, riser 115 is removed from riser adapter 145, connection 150 between LMRP 140 and BOP 120 is broken, and LMRP 140 is removed from BOP 120 according to block 507. Still further, if the selected landing site is wellhead 130, riser 115 is removed from riser adapter 145, connection 150 between LMRP 140 and BOP 120 is broken, LMRP 140 is removed from BOP 120, connection 150 between BOP 120 and wellhead 130 is broken, and BOP 120 is removed from wellhead 130 according to block 508.
It should be appreciated that identification of the landing site also influences whether a transition spool (e.g., transition spool 330) is necessary to couple the containment cap to landing site. For example, if the landing site includes a connector or hub (e.g., hub 150a) configured to mate and engage receptacle 150b at lower end 222b, then a transition spool is not necessary. On the other hand, if the landing site comprises a connector or hub that is not configured to mate and engage receptacle 150b at lower end 222b, then a transition spool is necessary to transition from receptacle 150b at lower end 222b to the particular type of connector or hub at the landing site.
Moving now to block 515, before, during, or after preparation of the landing site according to blocks 506, 507, 508, the transition spool (e.g., transition spool 330) and the containment cap components (e.g., assemblies 210, 250, 290 of containment cap 200, or assemblies 210, 450, cap 470, and coupling 480 of containment cap 400) are transported to the offshore deployment location. In general, the transition spool and containment cap components may be transported by air to a suitable onshore staging site, and then transported offshore by a boat or surface vessel. Air transport of the transition spool and/or any one or more of the components of the containment cap may be particularly desirable for transition spools and/or components stored or housed at a geographic locale that is distant the offshore deployment location since long range air transport is typically much faster than long range sea or land transport.
Once the transition spool (if necessary) and the assemblies of the containment cap 200, 400 have been transported to the offshore site, they may be deployed and installed subsea to form cap 200, 400 as previously described in block 520. Next, in block 525, wellbore 101 is contained and shut-in with containment cap 200, 400 as previously described. With wellbore 101 under control, flowback assembly 290 and/or conduit 235 may be used to produce wellbore 101 according to block 530.
Previously described was an embodiment in which a particular transition spool 330 was employed in order to couple containment cap 200 to riser adapter 145 of a particular flex joint 143. However, manufacturers have developed numerous types of riser flex joints, lower marine riser packages, BOPs, and wellheads. In particular, there are a number of potentially different connector profiles across riser flex joints, lower marine riser packages, BOPs, and wellheads. As previously described, in some cases, the landing site on the riser adapter, LMRP, BOP, or wellhead may have a connector or hub with a profile designed to directly mate and engage with receptacle 150b disposed at lower end 222b. However, in other cases, the landing site may have a connector or hub with a profile that is not compatible with receptacle 150b at lower end 222b. In such embodiments, a transition spool is employed to transition between the connector profile at the landing site and receptacle 150b at lower end 222b. Consequently, a variety of differently configured transition spools are required to transition between receptacle 150b at end 222b to the numerous connector profiles at the landing site. This may be best explained with reference to
More particularly,
Referring now to
Lower spool 620 has a central axis 625, a first or upper end 620a, and a second or lower end 620b. In addition, lower portion 620 includes an annular flange 621 at upper end 620a, a connector 624 at lower end 620b, a frustoconical body 622 extending axially from flange 621, and a tubular body 623 extending from body 622 to connector 624. A through bore 626 extends axially through spool 620 from upper end 620a to lower end 620b. Flange 621 is configured the same as flange 613 previously described. In particular, flange 621 includes an annular planar facing surface 627 having an annular groove (not shown) and a plurality of circumferentially-spaced holes 629 extend axially therethrough. Connector 624 at lower end 620b is configured to mate and sealingly engage with a complementary connector on the landing site (e.g., riser adapter 145, LMRP mandrel 151, BOP 120, wellhead 130). Due to the number of possible connectors across the various landing sites, connector 624 may comprise any one of a number of possible connectors described in more detail below. For connection to a flange at the landing site, connector 624 may comprise a mating flange including alignment pins to facilitate the alignment of the mating flanges.
To connect upper spool 610 to lower spool 620, an annular seal 630 formed of inconel or other suitable material is positioned in the annular grooves in facing surfaces 616, 627, spools 610, 620 are coaxially aligned, and flanges 613, 621 are pushed into engagement with each other. With holes 618, 629 aligned, threaded studs 631 and hex nuts 632 fasten together upper and lower spools 610, 620.
Referring now to
In
As will thus be understood, a single containment cap (e.g., cap 200, 400) can be employed so as to shut in and contain a well by placement of the cap at any one of four locations (on the well head 130, on the BOP 120, on the mandrel 151 of LMRP 140, or on the riser adapter 145). This may be accomplished by maintaining an inventory of multiple transition spools 600, with such transition spools 600 having identical upper portions 610 and differing lower portions 620 to accommodate different landing sites. As used herein, the term “inventory” when used as a noun means a collection of goods held in stock. Similarly, the word “inventory” when used as a verb and the phrase “maintaining an inventory” mean keeping the collection of goods on hand and ready for disposition. For a given well, the connector profiles of wellhead, the BOP, the mandrel of LMRP and of the riser adapter are all known such that the proper transition spool(s) 600 may be maintained at the surface vessel or drilling rig 110, or at a more distant storage facility. For example, a storage facility can be used for housing and maintaining one of each type of transition spool 600 that might be necessary for use with all the wells in a given region, such as the Gulf of Mexico. The inventory would include, in addition to the appropriate transition spools 600, at least one containment cap 200, 400 (preferably stored in its modular form). Should a well blowout occur, the modular components of the containment cap, as well as the transition spools necessary may be identified, selected from the inventory, and shipped expeditiously to the well site for use in capping the well.
Referring to
Referring now to
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 modular containment cap for containing a subsea wellbore discharging hydrocarbons into the surrounding sea, comprising:
- a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end;
- an upper assembly including a spool piece having an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, and a first spool piece valve disposed in the throughbore, wherein the first spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece;
- wherein the upper end of the spool body is releasably connected to the lower end of the spool piece, and wherein the first throughbore of the spool body is coaxially aligned with and in fluid communication with the throughbore of the spool piece.
2. The containment cap of claim 1, wherein the spool body of the lower assembly further comprises:
- a second throughbore extending from the first throughbore;
- a first spool body valve disposed in the second throughbore; and
- wherein the first spool body valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.
3. The containment cap of claim 1, wherein the upper assembly further comprising a second spool piece valve disposed in the throughbore of the spool piece of the upper assembly, wherein the second spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece of the upper assembly;
- wherein the spool body of the lower assembly further comprises a second spool body valve disposed in the second throughbore, wherein the second spool body valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.
4. The containment cap of claim 2, wherein the second throughbore has a first end intersecting the first throughbore and a second end distal the first throughbore, wherein the second end of the second throughbore is coupled to a choke valve.
5. The containment cap of claim 4, wherein the lower assembly further comprises a fluid conduit extending from the choke valve, wherein the fluid conduit has a first end coupled to the choke valve and a second end distal the choke valve, and wherein the second end of the fluid conduit comprises an upward-facing hub configured to releasably engage a mating downward-facing receptacle.
6. The containment cap of claim 2, wherein the first throughbore of the spool body is configured to provide full bore access to the wellbore.
7. The containment cap of claim 2, further comprising:
- a kill-flowback assembly including a spool piece having an upper end, a lower end opposite the upper end, and a throughbore extending from the upper end to the lower end;
- wherein the upper end of the spool piece of the upper assembly is releasably connected to the lower end of the spool piece of the kill-flowback assembly, and wherein the throughbore of the spool piece of the upper assembly is coaxially aligned with and in fluid communication with the throughbore of the spool piece of the kill-flowback assembly.
8. The containment cap of claim 7, wherein the kill-flowback assembly includes a fluid conduit coupled to the upper end of the spool piece of the kill-flowback assembly, wherein the fluid conduit is configured to produce the wellbore or supply kill fluids to the wellbore.
9. The containment cap of claim 7, wherein the lower assembly, the upper assembly, and the kill-flowback assembly are each configured to be air freightable.
10. The containment cap of claim 9, wherein the lower assembly has a first weight, the upper assembly has a second weight, and the kill-flowback assembly has a third weight;
- wherein the first weight, the second weight, and the third weight are each less than 120 tons.
11. The containment cap of claim 10, wherein the sum of any two of the first weight, the second weight, and the third weight is less than 120 tons.
12. The containment cap of claim 10, wherein the lower assembly, the upper assembly, and the kill-flowback assembly each has a maximum height, a maximum width, and a maximum length; and
- wherein at least one of the maximum height, the maximum width, and the maximum length of each of the lower assembly, the upper assembly, and the kill-flowback assembly is less than 21 ft. and at least a different one of the maximum height, the maximum width, and the maximum length of each of the lower assembly, the upper assembly, and the kill-flowback assembly is less than 14 ft.
13. The containment cap of claim 7, wherein the lower assembly comprises a frame coupled to the spool body, the upper assembly comprises a frame coupled to the spool piece of the upper assembly, and the kill-flowback assembly comprises a frame coupled to the spool piece of the kill-flowback assembly; and
- wherein the frame of the lower assembly is configured to support the spool body, the frame of the upper assembly is configured to support the spool piece of the upper assembly, and the frame of the kill-flowback assembly is configured to support the spool piece of the kill-flowback assembly.
14. The containment cap of claim 2, wherein the lower end of the spool body comprises a downward-facing receptacle configured to engage an upward-facing hub to form a wellhead-type connection;
- wherein the upper end of the spool body comprises an upward-facing hub that releasably engages a mating downward-facing receptacle at the lower end of the spool piece to form a wellhead-type connection between the spool body and the spool piece; and
- wherein the upper end of the spool piece comprises an upward-facing hub configured to engage a downward-facing receptacle to form a wellhead-type connection.
15. A method for containing and/or producing a subsea wellbore discharging hydrocarbons into the surrounding sea, wherein a wellhead is disposed at the sea floor at the upper end of the wellbore, a subsea BOP is mounted to the wellhead, an LMRP is mounted to the BOP, and a riser extends from the LMRP, the method comprising:
- (a) selecting a subsea landing site from one of the BOP, the LMRP, or the wellhead;
- (b) preparing the landing site for connection to a modular containment cap, wherein the containment cap comprises a lower assembly including a spool body and an upper assembly including a spool piece;
- (c) transporting the lower assembly and the upper assembly to an offshore location;
- (d) lowering the lower assembly subsea and releasably connecting the lower assembly to the landing site;
- (e) lowering the upper assembly subsea and releasably connecting the upper assembly to the lower assembly;
- (f) shutting in the wellbore with the containment cap after (d) and (e).
16. The method of claim 15, wherein the spool body of the lower assembly has an upper end, a lower end opposite the upper end, a first throughbore extending from the upper end to the lower end, a second throughbore extending from the first throughbore, a first spool body valve disposed in the second throughbore, and a second spool body valve disposed in the second throughbore;
- wherein the spool piece of the upper assembly has an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, a first spool piece valve disposed in the throughbore, and a second spool piece valve disposed in the throughbore;
- wherein the upper end of the spool body is releasably connected to the lower end of the spool piece, and wherein the first throughbore of the spool body is in fluid communication with the throughbore of the spool piece.
17. The method of claim 16, further comprising:
- opening the first spool body valve and the second spool body valve before (d); and
- opening the first spool piece valve and the second spool piece valve before (e).
18. The method of claim 17, wherein (f) comprises:
- (f1) closing the first spool piece valve;
- (f2) closing the first spool body valve after (f1).
19. The method of claim 18, wherein (f) further comprises:
- closing the second spool piece valve after (f1); and closing the second spool body valve after (f2).
20. The method of claim 18, further comprising:
- flowing at least a portion of the hydrocarbon fluids through the first throughbore and the second throughbore before (f);
- flowing at least a portion of the hydrocarbon fluids through the throughbore of the spool piece before (f);
- restricting the flow of the hydrocarbon fluids through the throughbore of the spool piece after (f1);
- flowing at least a portion of the hydrocarbon fluids through the second throughbore after (f1); and
- restricting the flow of the hydrocarbon fluids through the first throughbore and the second throughbore after (f2).
21. The method of claim 15, wherein the LMRP has an upper end including a riser flex joint connected to the riser, and wherein the subsea landing site is a riser adapter of the flex joint; and
- wherein (b) comprises removing the riser from the riser flex joint before (d).
22. The method of claim 21, further comprising:
- lowering a transition spool subsea and connecting it to the riser flex joint; and
- wherein (d) comprises lowering the lower assembly subsea and releasably connecting the lower assembly to the transition spool.
23. The method of claim 22, wherein the transition spool has a longitudinal axis, an upper end, a lower end comprising a mule shoe, and an annular flange axially disposed between the upper end and the mule shoe.
24. The method of claim 15, wherein the subsea landing site is an upward-facing hub at an upper end of the BOP or an upper end of the wellhead;
- wherein (d) comprises releasably connecting a downward-facing receptacle at a lower end of the lower assembly with the upward-facing hub.
25. The method of claim 16, further comprising:
- lowering a kill-flowback assembly subsea and releasably connecting the kill-flowback assembly to the upper assembly after (e).
26. The method of claim 25, wherein (f) further comprises:
- Pumping kill weight fluids through the kill-flowback assembly, the upper assembly, and the lower assembly into the wellbore.
27. The method of claim 25, further comprising:
- (g) producing the hydrocarbons through the kill-flowback assembly.
28. The method of claim 15, wherein (c) comprises:
- (c1) transporting the lower assembly and the upper assembly by air from a first land location to a second land location.
29. The method of claim 27, wherein (c) further comprises:
- (c2) transporting the lower assembly and the upper assembly from the second location to an onshore location; and
- (c3) transporting the lower assembly and the upper assembly from the onshore location to the offshore location by surface vessel.
30. A containment cap for containing a subsea wellbore discharging hydrocarbons into the surrounding sea, comprising:
- a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end;
- a valve assembly slidingly disposed in the first throughbore, wherein the valve assembly comprises a tubular body and a first spool body valve, wherein the tubular body has an upper end extending from the first throughbore, a lower end disposed within the first throughbore, and a throughbore extending between the upper end and the lower end of the tubular body;
- wherein the first spool body valve is disposed along the throughbore of the tubular body and is configured to control the flow of fluids through the throughbore of the tubular body;
- a plurality of annular seal assemblies radially positioned between the spool body and the tubular body, wherein each seal assembly is configured to restrict the flow of fluids between the tubular body and the spool body.
31. The containment cap of claim 30, wherein the spool body of the lower assembly further comprises:
- a second throughbore extending from the first throughbore;
- a first valve disposed in the second throughbore; and
- wherein the first valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.
32. The containment cap of claim 31, wherein the valve assembly further comprises a second spool body valve disposed along the throughbore of the tubular body and configured to control the flow of fluids through the throughbore of the tubular body;
- wherein the spool body of the lower assembly further comprises a second valve disposed in the second throughbore;
- wherein the second valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.
33. The containment cap of claim 31, further comprising an annular insert disposed in the first throughbore and axially positioned between the tubular body and an annular shoulder in the first throughbore, wherein the lower end of the tubular body is seated in a cylindrical recess in the insert.
34. The containment cap of claim 30, further comprising a cap disposed about the upper end of the tubular body, wherein the cap has an upper end comprising an upward-facing hub, a lower end comprising a downward-facing hub, and a flow passage extending from the lower end to the upper end;
- wherein the flow passage is in fluid communication with the throughbore of the tubular body.
35. The containment cap of claim 34, further comprising an annular coupling member disposed about the lower end of the cap and the upper end of the spool body, wherein the coupling member has an upper end comprising an upward-facing receptacle and a lower end comprising a downward-facing receptacle;
- wherein the downward-facing hub at the lower end of the cap releasably engages the receptacle at the upper end of the coupling member, and an upward-facing hub at the upper end of the spool body releasably engages the receptacle at the lower end of the coupling member.
36. The containment cap of claim 31, wherein the second throughbore has a first end intersection the first throughbore and a second end distal the first throughbore, wherein the second end of the second throughbore is coupled to a choke valve.
37. The containment cap of claim 36, wherein the lower assembly further comprises a fluid conduit extending from the choke valve, wherein the fluid conduit has a first end coupled to the choke valve and a second end distal the choke valve, and wherein the second end of the fluid conduit comprises an upward-facing hub configured to releasably engage a mating downward-facing receptacle.
38. The containment cap of 31, wherein the first throughbore of the spool body is configured to provide full bore access to the wellbore.
39. The containment cap of claim 35, wherein the lower assembly, the valve assembly, the cap, and the coupling member are each configured to be air freightable.
40. The containment cap of claim 39, wherein the lower assembly has a first weight and the valve assembly has a second weight;
- wherein the sum of the first weight and the second weight is less than 120 tons.
Type: Application
Filed: May 10, 2012
Publication Date: Dec 20, 2012
Applicant: BP Corporation North America Inc. (Houston, TX)
Inventors: Robert Winfield Franklin (Katy, TX), Richard Harland (Houston, TX), Stuart Douglas Rettie (Houston, TX), Roy Bryant Shilling, III (Houston, TX)
Application Number: 13/468,872
International Classification: E21B 33/035 (20060101);