WO2015153818A2

WO2015153818A2 - Systems for sub-ambient pressure assisted actuation of subsea hydraulically actuated devices and related methods

Info

Publication number: WO2015153818A2
Application number: PCT/US2015/023959
Authority: WO
Inventors: Jeremy MAUNUS; Matthew Blieske; Guy Robert Babbitt
Original assignee: Transocean Innovation Labs Ltd
Priority date: 2014-04-01
Filing date: 2015-04-01
Publication date: 2015-10-08
Also published as: WO2015153818A3; US20150308212A1

Abstract

This disclosure includes systems and methods for actuation of subsea hydraulically actuated devices. Some systems use or include one or more subsea reservoirs, each having a body defining an interior volume configured to contain a sub-ambient internal pressure, the body defining an outlet in fluid communication with the interior volume, and a hydraulic power delivery system including one or more subsea valves configured to selectively allow fluid communication between the outlet of at least one of the reservoir(s) and a first port of the hydraulically actuated device. In some systems, the hydraulic power delivery system includes a rigid sliding member configured to unseal a selectively sealed outlet of at least one of the reservoir(s). In some systems, the subsea valve(s) are configured to alternatively allow fluid communication between the outlet of the at least one of the reservoir(s) and the first or a second port of the hydraulically actuated device.

Description

SYSTEMS FOR SUB-AMBIENT PRESSURE ASSISTED ACTUATION OF SUBSEA HYDRAULIC ALLY ACTUATED DEVICES AND RELATED METHODS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 61/973,782, entitled "SYSTEMS AND METHODS FOR LOW-PRESSURE ACTUATION OF SUBSEA HYDRAULIC RAMS," filed April 1, 2014, the content of which is incorporated by reference in its entirety.

BACKGROUND

1. Field of Invention

[0002] The present invention relates generally to subsea blowout preventers, and more specifically, but not by way of limitation, to systems and methods for sub-ambient pressure assisted actuation of subsea hydraulically actuated devices.

2. Description of Related Art

[0003] A blowout preventer (BOP) is a mechanical device, usually installed redundantly in stacks, used to seal, control, and/or monitor oil and gas wells. Typically, a blowout preventer includes a number of devices, such as, for example, rams, annulare, accumulators, test valves, failsafe valves, kill and/or choke lines and/or valves, riser joints, hydraulic connectors, and/or the like, many of which may be hydraulically actuated.

[0004] Such hydraulically actuated devices (amongst others) typically require sources of high pressure for actuation. In subsea applications, and particularly those in which the subsea environment is used as a pressure sink, pressure requirements for such sources of high pressure generally increase with depth below the sea surface.

[0005] Examples of sub-ambient pressure assisted actuation of subsea hydraulically actuated devices are disclosed in U.S. Patent Nos.: (1) 8,387,706; and (2) 8,602,109.

SUMMARY

[0006] Some embodiments of the present systems are configured to allow for sub-ambient pressure assisted actuation of two or more functions of a subsea hydraulically actuated device (e.g., an open function and a close function of a ram-type BOP) (e.g., through one or more subsea valves configured to alternatively allow fluid communication between one or more pressure sinks at sub-ambient pressures and: (1) a first port of the hydraulically actuated device; or (2) a second port of the hydraulically actuated device). Some embodiments of the present systems are configured, through one or more sealed reservoirs, each configured to contain a sub- ambient internal pressure, and a rigid sliding member configured to unseal at least one of the one or more reservoirs, to prevent internal pressure(s) of the one or more reservoirs from equalizing with other system pressures prior to use, reduce the risk of leakage from and/or into the one or more reservoirs prior to use, facilitate replacement of at least one of the one or more reservoirs, and/or the like.

[0007] Some embodiments of the present systems for actuating a subsea hydraulically actuated device comprise: one or more subsea reservoirs, each comprising a body defining an interior volume configured to contain an internal pressure that is lower than a pressure of a subsea environment outside of the body, the body defining an outlet in fluid communication with the interior volume, and a hydraulic power delivery system comprising one or more subsea valves, where the one or more subsea valves are configured to selectively allow fluid communication between the outlet of at least one of the one or more reservoirs and a first port of the hydraulically actuated device. In some embodiments, the one or more subsea valves are configured to alternatively allow fluid communication between the outlet of at least one of the one or more reservoirs and a first port of the hydraulically actuated device or a second port of the hydraulically actuated device.

[0008] In some embodiments, the outlet of at least one of the one or more subsea reservoirs is selective sealed, and the hydraulic power delivery system comprises a rigid sliding member (e.g., a ram, rod, penetrator, and/or the like) configured to unseal the outlet of at least one of the one or more reservoirs. In some embodiments, the outlet of at least one of the one or more reservoirs comprises a diaphragm, and the rigid sliding member is configured to puncture the diaphragm to unseal the outlet of at least one of the one or more reservoirs. In some embodiments, the rigid sliding member comprises a ram slidably disposed within a bore and movable between a first position and a second position, the ram configured to puncture the diaphragm of at least one of the one or more reservoirs as the ram is moved between the first position and the second position, where fluid communication between the bore and the outlet is permitted when the ram is in the second position.

[0009] In some embodiments, the one or more subsea valves are configured to selectively allow fluid communication between a pressure source and the first port of the hydraulically actuated device. In some embodiments, the one or more subsea valves comprises a first three- way valve configured to selectively allow fluid communication between the pressure source and the first port of the hydraulically actuated device and selectively allow fluid communication between the outlet of at least one of the one or more reservoirs and the first port of the hydraulically actuated device. In some embodiments, the one or more subsea valves comprises a first two-way valve configured to selectively allow fluid communication between the pressure source and the first port of the hydraulically actuated device and a second two-way valve configured to selectively allow fluid communication between the outlet of at least one of the one or more reservoirs and the first port of the hydraulically actuated device.

[0010] In some embodiments, the one or more subsea valves are configured to selectively allow fluid communication between a pressure source and the second port of the hydraulically actuated device. In some embodiments, the one or more subsea valves comprises a second three- way valve configured to selectively allow fluid communication between the pressure source and the second port of the hydraulically actuated device and selectively allow fluid communication between the outlet of at least one of the one or more reservoirs and the second port of the hydraulically actuated device. In some embodiments, the one or more subsea valves comprises a third two-way valve configured to selectively allow fluid communication between the pressure source and the second port of the hydraulically actuated device and a fourth two-way valve configured to selectively allow fluid communication between the outlet of at least one of the one or more reservoirs and the second port of the hydraulically actuated device.

[0011] In some embodiments, the pressure source comprises sea water from a subsea environment. In some embodiments, the pressure source comprises a subsea pump. In some embodiments, the pressure source comprises a hydraulic power unit.

[0012] In some embodiments, at least one of the one or more reservoirs comprises an accumulator. In some embodiments, the accumulator comprises a piston-type accumulator. In some embodiments, the accumulator comprises a bladder-type accumulator. In some embodiments, at least one of the one or more reservoirs is pressure-compensated. In some embodiments, the one or more reservoirs comprises two or more reservoirs. In some embodiments, the one or more reservoirs are coupled to a BOP stack. In some embodiments, at least one of the one or more reservoirs is configured to be retrievable by a remotely-operated underwater vehicle (ROV). [0013] In some embodiments, at least one of the one or more subsea valves comprises a hydraulically piloted subsea valve. In some embodiments, at least one of the one or more subsea valves comprises an electrohydraulic servo valve. In some embodiments, the one or more subsea valves are coupled to a manifold.

[0014] In some embodiments, the hydraulically actuated device comprises a BOP, the first port comprises an open port, and the second port comprises a close port. Some embodiments comprise a battery configured to supply electrical power to the hydraulic power delivery system. Some embodiments comprise one or more sensors configured to capture data indicative of at least one of pressure, flow rate, and temperature of hydraulic fluid within the hydraulic power delivery system.

[0015] Some embodiments of the present methods for actuating a subsea hydraulically actuated device comprise: unsealing a sealed outlet of a subsea reservoir, the reservoir defining an interior volume in fluid communication with the outlet, the interior volume containing an internal pressure that is lower than a pressure of a subsea environment outside of the reservoir, and placing the outlet of the reservoir into fluid communication with a first port of the hydraulically actuated device. In some embodiments, unsealing the sealed outlet of the reservoir comprises puncturing a seal of the reservoir. Some embodiments comprise placing a second port of the hydraulically actuated device into fluid communication with a pressure source.

[0016] Some embodiments of the present methods for actuating a subsea hydraulically actuated device comprise: selecting a first port from at least two ports of the hydraulically actuated device and placing the selected first port into fluid communication with an interior volume of a subsea reservoir, the interior volume containing an internal pressure that is lower than a pressure of a subsea environment outside of the reservoir. Some embodiments comprise placing a second port of the at least two ports of the hydraulically actuated device into fluid communication with a pressure source. Some embodiments comprise selecting a second port from the at least two ports of the hydraulically actuated device and placing the selected second port into fluid communication with the interior volume of the subsea reservoir. Some embodiments comprise placing the selected first port into fluid communication with a pressure source.

[0017] The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are "coupled" may be unitary with each other. The terms "a" and "an" are defined as one or more unless this disclosure explicitly requires otherwise. The term "substantially" is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed embodiment, the term "substantially" may be substituted with "within [a percentage] of what is specified, where the percentage includes .1, 1, 5, and 10 percent.

[0018] Further, a device or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described.

[0019] The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), '¾ave" (and any form of have, such as '¾as" and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, an apparatus that "comprises," '¾as," "includes," or "contains" one or more elements possesses those one or more elements, but is not limited to possessing only those elements. Likewise, a method that "comprises," "has," "includes," or "contains" one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps.

[0020] Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of - rather than comprise/include/contain/have - any of the described steps, elements, and/or features. Thus, in any of the claims, the term "consisting of or "consisting essentially of can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb.

[0021] The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments.

[0022] Some details associated with the embodiments are described above and others are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. Views in the figures are drawn to scale (unless otherwise noted), meaning the sizes of the elements depicted in a view are accurate relative to each other for at least the embodiment depicted in the view.

[0024] FIG. 1 is a diagram of a first embodiment of the present systems for actuating a subsea hydraulically actuated device.

[0025] FIG. 2 is a diagram of a second embodiment of the present systems for actuating a subsea hydraulically actuated device.

[0026] FIG. 3 is a diagram of a third embodiment of the present systems for actuating a subsea hydraulically actuated device.

[0027] FIGs. 4A and 4B are perspective and cross-sectional perspective views, respectively, of a reservoir, which may be suitable for use in some embodiments of the present systems.

[0028] FIG. 5 is a diagram of a reservoir bank, which may be suitable for use in some embodiments of the present systems.

[0029] FIG. 6A is a cross-sectional side view of an accumulator, which may be suitable for use in some embodiments of the present systems.

[0030] FIG. 6B is a cross-sectional side view of an accumulator, which may be suitable for use in some embodiments of the present systems.

[0031] FIG. 7 is a perspective view of an opening mechanism, which may be suitable for use in some embodiments of the present systems.

[0032] FIG. 8A is a cross-sectional side view of the opening mechanism of FIG. 7, shown with a rigid sliding member in a first position.

[0033] FIG. 8B is a cross-sectional side view of the opening mechanism of FIG. 7, shown with a rigid sliding member in a second position.

[0034] FIG. 8C is a cross-sectional perspective view of the opening mechanism of FIG. 8A.

[003S] FIG. 8D is a cross-sectional perspective view of the opening mechanism of FIG. 8B.

[0036] FIG. 9 is a perspective view of a ram, which may be suitable for use as a rigid sliding member in some embodiments of the present opening mechanisms.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0037] Referring now to the drawings, and more particularly to FIG. 1, shown therein and designated by the reference numeral 10a is a first embodiment of the present systems. In the embodiment shown, system 10a is configured for actuating a subsea hydraulically actuated device 14. The present systems can be configured to actuate any suitable hydraulically actuated device(s) (e.g., 14), such as, for example, ram(s), annular(s), accumulators), test valve(s), failsafe valve(s), kill and/or choke line(s) and/or valve(s), riser joint(s), hydraulic connector(s), and/or the like. Such hydraulically actuated devices (e.g., 14) may include ports through which pressure (e.g., pressurized fluid) may be conveyed to actuate one or more functions of the hydraulically actuated devices. For example, in this embodiment, hydraulically actuated device 14 comprises a ram-type BOP (only partially depicted), having a first port 18 (e.g., a ram-close port) and a second port 22 (e.g., a ram open port). In the depicted embodiment, hydraulically actuated device 14 comprises a first chamber 26 (e.g., a ram-close chamber) in fluid communication with first port 18 and a second chamber 30 (e.g., a ram-open chamber) in fluid communication with second port 22 , where a piston 34 separates and is in fluid communication with each of the first and second chambers. To illustrate, in the embodiment shown, as a pressure within first chamber 26 is increased and/or as a pressure within second chamber 30 is reduced, differences of internal pressures between the first chamber and the second chamber may cause piston 34 to move such that hydraulically actuated device 14 may actuate or begin to actuate a first function (e.g., a ram-close function). To further illustrate, in this embodiment, as a pressure within second chamber 30 is increased and/or as a pressure within first chamber 26 is reduced, differences of internal pressures between the first chamber and the second chamber may cause piston 34 to move such that hydraulically actuated device 14 may actuate or begin to actuate a second function (e.g., a ram-open function).

[0038] In the depicted embodiment, system 10a comprises a hydraulic power delivery system 38a. In this embodiment, hydraulic power delivery system 38a is configured to allow fluid communication between one or more ports (e.g., 18, 22) of one or more hydrauUcally actuated devices (e.g., 14) and one or more pressure sources (e.g., sources at a higher pressure than one or more pressure sinks) and/or one or more pressure sinks (e.g., sources at sub-ambient pressures, or pressures lower than a pressure of a subsea environment, for example, a subsea environment in which one or more reservoirs 46 are disposed) to cause actuation of the one or more hydrauUcally actuated devices. In these ways and others, pressure requirements for a given pressure source to effectively actuate a hydrauUcally actuated device may be reduced, a pressure differential (e.g., between one or more pressure sources and one or more pressure sinks) available to actuate a hydraulically actuated device may be increased, and/or the like.

[0039] As will be described in more detail below, such fluid communication may be controlled via operation of one or more subsea valves (e.g., 58a, 58b, and/or the like), ones of which (e.g., up to and including each of which) may be coupled to (e.g., at least partially disposed within) a manifold 62a. Subsea valves of the present systems may comprise any suitable valve, such as, for example a spool valve, poppet valve, ball valve, electrohydraulic servo valve, and/or the like, in any suitable configuration, such as, for example, two-position two-way (2P2W), 2P3W, 2P4W, 3P4W, and/or the like, and may or may not be piloted (e.g., hydraulically, electrically, mechanically, and/or the like).

[0040] Provided by way of example, in the embodiment shown, hydraulic power delivery system 38a is configured to allow fluid communication between one or more ports (e.g., 18 and/or 22) of hydraulically actuated device 14 and a subsea environment 42a (e.g., a pressure source) and/or one or more subsea reservoirs 46 (e.g., which may be configured as a pressure sink, described in more detail below). In embodiments configured to use subsea environment 42a as a pressure source (e.g., 10a), one or more shuttle valves (e.g., 50) may be used to mitigated undesired hydraulic fluid loss to the subsea environment and/or one or more filters (e.g., 54) may be used to mitigate the introduction of contaminants from the subsea environment into a respective hydraulic power delivery system (e.g., 38a). However, the present systems (e.g., 10a, 10b, 10c, and/or the like) and/or respective hydraulic power delivery systems (e.g., 38a, 38b, 38c, and/or the like) may be used with any suitable pressure source(s) (e.g., subsea environment 42a, subsea pump(s) 42b, hydraulic power unit(s) 42c, which may be in fluid communication with the respective hydraulic power delivery systems via hot line(s), rigid conduit(s), and/or the like) and/or any suitable pressure sink(s) (e.g., one or more above sea reservoirs, one or more subsea reservoirs (e.g., 46), subsea pump(s), hydraulic power unit(s), and/or the like).

[0041] As mentioned above, in this embodiment, hydraulic power delivery system 38a comprises one or more subsea valves configured to selectively allow fluid communication between at least one of one or more reservoirs 46 and a first port (e.g., 18) of hydraulically actuated device 14. For example, in the depicted embodiment, hydraulic power delivery system 38a comprises a first three-way valve 58a configured to selectively allow fluid communication between at least one of one or more reservoirs 46 and the first port (e.g., 18) of hydraulically actuated device 14. In the embodiment shown, one or more subsea valves are configured to selectively allow fluid communication between a pressure source and the first port (e.g., 18) of hydraulically actuated device 14. For example, in this embodiment, first three-way valve 58a is configured to selectively allow fluid communication between subsea environment 42a and the first port (e.g., 18) of hydraulically actuated device 14.

[0042] In the depicted embodiment, one or more subsea valves are configured to selectively allow fluid communication between at least one of one or more reservoirs 46 and a second port (e.g., 22) of hydraulically actuated device 14. For example, in the embodiment shown, hydraulic power delivery system 38a comprises a second three-way valve 58b configured to selectively allow fluid communication between at least one of one or more reservoirs 46 and the second port (e.g., 22) of hydraulically actuated device 14. In this embodiment, one or more subsea valves are configured to selectively allow fluid communication between a pressure source and the second port (e.g., 22) of hydraulically actuated device 14. For example, in the depicted embodiment, second three-way valve 58b is configured to selectively allow fluid communication between subsea environment 42a and the second port (e.g., 22) of hydraulically actuated device 14. In some embodiments, one or more valves may be configured such that fluid communication between a pressure source (e.g., 42a) and a respective first port (e.g., 18 or 22) may cause fluid communication between a pressure sink (e.g., one or more subsea reservoirs 46) and a respective second port (e.g., 18 or 22, but not the first port).

[0043] In the embodiment shown, one or more subsea valves are configured to alternatively allow fluid communication between at least one of one or more reservoirs 46 and: (1) a first port (e.g., 18 or 22) of hydraulically actuated device 14; or (2) a second port (e.g., 18 or 22, but not the first port) of the hydraulically actuated device. For example, in this embodiment, first three- way valve 58a may be actuated to allow fluid communication between at least one of one or more reservoirs 46 and first port 18, and second three-way valve 58b may be actuated to block fluid communication between the at least one of the one or more reservoirs and second port 22. For further example, in the depicted embodiment, second three-way valve 58b may be actuated to allow fluid communication between at least one of one or more reservoirs 46 and second port 22, and first three-way valve 58a may be actuated to block fluid communication between the at least one of the one or more reservoirs and first port 18. [0044] In the embodiment shown, hydraulic power delivery system 38a comprises a subsea pump 66, which may be configured to recharge at least one of one or more reservoirs 46 (e.g., by removing hydraulic fluid from within the at least one of the one or more reservoirs, for example, when the at least one of the one or more reservoirs is at least partially filled with hydraulic fluid after use as a pressure sink). In this embodiment, hydraulic power delivery system 38a comprises one or more ROV stabs 70, which may be configured to allow ROV control of hydraulic power delivery system 38a and/or components thereof, such as, for example, one or more subsea valves (e.g., 58a, 58b, and/or the like).

[0045] Referring now to FIG. 2, shown therein and designated by the reference numeral 10b is a second embodiment of the present systems. In the embodiment shown, system 10b, and more particularly, hydraulic power delivery system 38b, is configured to provide pressure (e.g., pressurized fluid) from multiple pressure sources to ports (e.g., 18, 22) of hydraulically actuated device 14 (e.g., via operation of one or more subsea valves, such as, for example, 58c, 58d, 74, and/or the like, which may be coupled to a manifold 62b, for example, at least partially disposed within the manifold). For example, in this embodiment, one or more valves are configured to provide pressure (e.g., pressurized fluid) from one or more subsea pumps 42b (e.g., each of which may comprise an independent pressure source) and/or a hydraulic power unit 42c to a first port (e.g., 18) of hydraulically actuated device 14. For further example, in the depicted embodiment, one or more valves are configured to provide pressure (e.g., pressurized fluid) from one or more subsea pumps 42b (e.g., each of which may comprise an independent pressure source) and/or a hydraulic power unit 42c to a second port (e.g., 22) of hydraulically actuated device 14. In the embodiment shown, hydraulic power delivery system 38b comprises one or more isolation valves 74, which may be configured to isolate one or more pressure sources (e.g., one or more subsea pumps 42b, hydraulic power unit 42c, and/or the like) and/or one or more pressure sinks (e.g., one or more tanks 46) from one another.

[0046] As with system 10a, system 10b comprises three-way valves, 58c and 58d, each configured to selectively allow fluid communication between a respective pressure source and a respective port of hydraulically actuated device 14 and each configured to selectively allow fluid communication between a respective at least one of one or more reservoirs 46 and the respective port of the hydraulically actuated device. In this embodiment, three-way valves 58c and 58d are each hydraulically piloted (e.g., as shown) (e.g., by electrically actuated pilot valves, which may receive power from a battery 72, umbilical cable, and/or the like).

[0047] Referring now to FIG. 3, shown therein and designated by the reference numeral 10c is a third embodiment of the present systems. System 10c comprises sets of two or more two- way valves, each set configured to perform a same or similar function as a three-way valve (e.g., three-way valves 58a and/or 58b of system 10a, three-way valves 58c and/or 58d of system 10b, and/or the like). For example, in the embodiment shown, one or more subsea valves (e.g., 58c, 58f, 58g, 58h, 74, and/or the like) (e.g., which may be coupled to a manifold 62c, for example, at least partially disposed within the manifold) comprises a first two-way valve 58c configured to selectively allow fluid communication between a pressure source (e.g., one or more subsea pumps 42b) and a first port (e.g., 18) of hydraulically actuated device 14. In this embodiment, one or more subsea valves comprises a second two-way valve 58f configured to selectively allow fluid communication between at least one of one or more reservoirs 46 and the first port (e.g., 18) of hydraulically actuated device 14. In the depicted embodiment, one or more subsea valves comprises a third two-way valve 58g configured to selectively allow fluid communication between a pressure source (e.g., one or more subsea pumps 42b) and a second port (e.g., 22) of hydraulically actuated device 14. In the embodiment shown, one or more subsea valves comprises a fourth two-way valve 58h configured to selectively allow fluid communication between at least one of one or more reservoirs 46 and the second port (e.g., 22) of the hydraulically actuated device.

[0048] As with system 10a, in the embodiment shown, one or more subsea valves are configured to alternatively allow fluid communication between at least one of one or more reservoirs 46 and: (1) a first port (e.g., 18 or 22) of hydraulically actuated device 14; or (2) a second port (e.g., 18 or 22, but not the first port) of the hydraulically actuated device. For example, in this embodiment, second two-way valve 58f may be actuated to allow fluid communication between at least one of one or more reservoirs 46 and first port 18, and fourth two-way valve 58h may be actuated to block fluid communication between the at least one of the one or more reservoirs and second port 22. For further example, in the depicted embodiment, fourth two-way valve 58h may be actuated to allow fluid communication between at least one of one or more reservoirs 46 and second port 22, and second three-way valve 58f may be actuated to block fluid communication between the at least one of the one or more reservoirs and first port 18.

[0049] The use of two two-way valves (e.g., as opposed to a single three-way valve) may facilitate system 10c, and more particularly, hydraulic power delivery system 38c, in reducing potential single points of failure. Thus, implementation of two two-way valves (e.g., as in hydraulic power delivery system 38c) can increase reliability and fault tolerance over a single (e.g., three-way) valve configuration, despite potentially requiring more components. Additionally, two-way valves are generally less expensive and less complicated than three-way valves and may provide for a better seal and be more robust.

[0050] In this embodiment, system 10c comprises one or more sensors 78 configured to capture data indicative of at least one of hydraulic fluid pressure, temperature, flow rate, and/or the like. One or more sensors (e.g., 78) of the present systems can comprise any suitable sensor, such as, for example, a temperature sensor (e.g., a thermocouple, resistance temperature detector (RTDs), and/or the like), pressure sensor (e.g., a piezoelectric pressure sensor, strain gauges and/or the like), position sensor (e.g., a Hall effect sensor, linear variable differential transformer, potentiometer, and/or the like), velocity sensor (e.g., an observation-based sensor, accelerometer-based sensor, and/or the like), acceleration sensor, flow sensor, current sensor, and/or the like, whether external and/or internal to manifold 62c, hydraulic power delivery system 38c, and/or system 10c, and whether virtual and/or physical. Data captured by at least one of one or more sensors 78 may be communicated to (e.g., an above-sea) controller, used, at least in part, to control system 10c (e.g., one or more valves thereof), and/or the like.

[00S1] Referring additionally to FIGs. 4A and 4B, shown are perspective and cross-sectional perspective views, respectively, of a reservoir 46a, which may be suitable for use in some embodiments of the present systems (e.g., 10a, 10b, 10c, and/or the like) (e.g., as at least one of one or more reservoirs 46). In the embodiment shown, reservoir 46a comprises a body 82 defining an interior volume 86 configured to contain and/or containing an internal pressure that is lower than a pressure of a subsea environment outside of the body (e.g., a sub-ambient pressure). In this embodiment, body 82 defines an outlet 90 in fluid communication with interior volume 86. In the depicted embodiment, outlet 90 of reservoir 46a is selectively sealed. For example, in the embodiment shown, outlet 90 of reservoir 46a is sealingly covered by a diaphragm 94 (e.g., which may prevent fluid communication into and/or from interior volume 86 through and/or out of outlet 90). Diaphragm 94 may be coupled to body 82 in any suitable fashion, such as, for example, via integral formation (e.g., such that the diaphragm is unitary with at least a portion of the body), interlocking features of the diaphragm and/or body (e.g., a threaded coupling between the diaphragm and the body), one or more fasteners, welding, and/or the like.

[0052] Referring additionally to FIG. S, shown is a diagram of a reservoir bank 98, which may be suitable for use in some embodiments of the present systems (e.g., 10a, 10b, 10c, and/or the like). As shown, in this embodiment, one or more reservoirs 46 comprises two or more reservoirs (e.g., five (5) reservoirs, as shown). In the depicted embodiment, reservoir bank 98 and/or one or more reservoirs 46 (e.g., whether or not the one or more reservoirs are disposed in a reservoir bank) may be coupled to a BOP and/or BOP stack.

[0053] In some embodiments, respective reservoir banks (e.g., 98) and/or at least one of respective one or more reservoirs (e.g., 46) may be configured to be ROV retrievable. For example, in the embodiment shown, reservoir bank 98 comprises one or more isolation valves 102, each in fluid communication with a respective one of one or more reservoirs 46. In this embodiment, at least one of one or more isolation valves 102 may be actuated to block fluid communication to and/or from a respective at least one of one or more reservoirs 46 (e.g., thus facilitating removal of the respective reservoir(s) from reservoir bank 98 and/or from system 10a, 10b, 10c, and/or the like).

[0054] In some embodiments, at least one of respective one or more reservoirs (e.g., 46) may comprise an accumulator. For example, FIG. 6A shows a cross-sectional side view of a (e.g., piston-type) accumulator 46b, which may be suitable for use in some embodiments of the present systems (e.g., 10a, 10b, 10c, and/or the like). In the embodiment shown, accumulator 46b comprises a body 106 defining an interior volume 110. In this embodiment, accumulator 46b comprises a piston 114 slidably disposed within interior volume 110 and configured separate the interior volume into a first portion 118 and a second portion 122 (e.g., and the piston may be biased towards the first portion or second portion via one or more springs and/or the like).

[0055] In the depicted embodiment, first portion 118 is configured to contain and/or contains an internal pressure that is lower than a pressure of a subsea environment outside of body 106 (e.g., a sub-ambient pressure). In the embodiment shown, second portion 122 is configured to receive hydraulic fluid (e.g., via outlet 90, which may be selectively sealed, similarly to as described above for reservoir 46a). In this embodiment, when accumulator 46b is placed in fluid communication with a port (e.g., 18 or 22) of a hydraulically actuated device (e.g., 14), an internal pressure within second portion 122 may increase, causing piston 114 to move towards first portion 118 (e.g., thus compressing a fluid, such as a gas, within the first portion). As shown, accumulator 46b comprises a valve 124 (e.g., to facilitate filling and/or re-filling of first portion 118 with fluid at a sub-ambient pressure).

[0056] For further example, FIG. 6B shows a cross-sectional side view of a (e.g., bladder- type) accumulator 46c, which may be suitable for use in some embodiments of the present systems (e.g., 10a, 10b, 10c, and/or the like). In the embodiment shown, accumulator 46c comprises a body 126 defining an interior volume 130 containing a flexible bladder 134 (e.g., whether elastic and/or inelastic). In the depicted embodiment, flexible bladder 134 is disposed within body 126 such that a wall of the flexible bladder defines two portions of interior volume 130: a first portion 138 within flexible bladder 134, and a second portion 142 outside of the flexible bladder.

[0057] In the embodiment shown, first portion 138 is configured to contain and/or contains an internal pressure that is lower than a pressure of a subsea environment outside of body 126 (e.g., a sub-ambient pressure). In this embodiment, second portion 142 is configured to receive hydraulic fluid (e.g., via outlet 90, which may be selectively sealed, similarly to as described above for reservoir 46a). In the depicted embodiment, when accumulator 46c is placed in fluid communication with a port (e.g., 18 and/or 22) of a hydraulically actuated device (e.g., 14), an internal pressure within second portion 142 may increase, causing portions of flexible bladder 134 to displace towards first portion 138 (e.g., thus compressing a fluid, such as a gas, within the flexible bladder). As shown, accumulator 46c comprises an anti-extrusion poppet valve 146 configured to prevent extrusion of flexible bladder 134 out of outlet 90.

[0058] Referring now to FIGs. 7 and 8A-8D, shown are various views of an opening mechanism 150, which may be suitable for use in some embodiments of the present systems (e.g., 10a, 10b, 10c, and/or the like), and more particularly, in some embodiments of the present hydraulic power delivery systems (e.g., 38a, 38b, 38c, and/or the like). In the embodiment shown, opening mechanism 150 comprises a body 154 defining a first bore 158 and a second bore 162, the second bore configured to be in fluid communication with the first bore. In this embodiment, opening mechanism 150 is configured to be coupled to a respective one of one or more reservoirs 46 (e.g., reservoir 46a, as shown) such that first bore 158 is in fluid communication with interior volume 86 of the respective reservoir (e.g., when outlet 90 of the respective reservoir is unsealed). In the depicted embodiment, second bore 162 is configured to connect opening mechanism 150 in fluid communication with other components (e.g., at least one of one or more subsea valves 58, at least one of one or more isolation valves 74, and/or the like) of the present systems.

[0059] In the depicted embodiment, opening mechanism 150 comprises a rigid sliding member 166. For example, in the embodiment shown, rigid sliding member 166 is slidably disposed within first bore 158 and movable relative to body 154 between a first position (FIGs. 8A, 8C) and a second position (FIGs. 8B, 8D) (e.g., generally along a direction indicated by arrow 174); however, the rigid sliding member may be movable beyond the first position and/or the second position. In this embodiment, rigid sliding member 166 is sealingly, yet slidably, engaged with first bore 158, for example, via one or more O-rings 170. Such movement of rigid sliding member 166 relative to body 154 between the first position and the second position may be accomplished in any suitable fashion, such as, for example, via one or more hydraulic, electric, magnetic, and/or pneumatic actuators (e.g., screw-type actuators, linear actuators, and/or the like), application of hydraulic pressure (e.g., to second end 188 of ram 178, described in more detail below), and/or the like.

[0060] In the depicted embodiment, rigid sliding member 166 is configured to unseal outlet 90 of reservoir 46a. For example, in the embodiment shown, rigid sliding member 166 is configured to puncture diaphragm 94 of reservoir 46a as the rigid sliding member is moved between the first position and the second position (e.g., as shown). Thus, in this embodiment, when rigid sliding member 166 is at and/or near the second position, fluid communication may be allowed between interior volume 86 and first and second bores, 158 and 162, respectively.

[0061] Referring additionally to FIG. 9, shown is perspective view of ram 178, which may be suitable for use as a rigid sliding member in some embodiments of the present opening mechanisms (e.g., 150). In the embodiment shown, ram 178 comprises a body 182 having a first end 186 defining a puncturing tip, surface, or edge 190 (e.g., configured to puncture, cut, and/or otherwise rupture diaphragm 94 of reservoir 46a) and a second end 188.

[0062] In this embodiment, body 182 has dimensions that correspond to interior dimensions of first bore 158 such that ram 178 may be slidably disposed within the first bore. For example, in this embodiment, body 182 has a maximum transverse dimension 194 that corresponds to or substantially equals (e.g., is slightly smaller than) a maximum transverse dimension 198 of first bore 158. In this embodiment, body 182 comprises a substantially circular cross-section (e.g., which corresponds to a cross-section of first bore 158) (e.g., with the exceptions of portion(s) of the body that define one or more grooves 206 and/or neck portion 210, described in more detail below). However, in other embodiments, bodies (e.g., 182) of respective rams (e.g., 178) may comprise portions having any suitable cross-section(s), such as, for example, circular, elliptical, and/or otherwise rounded cross-section(s), triangular, rectangular, and/or otherwise polygonal cross-section(s), and/or the like. In embodiments where portions of bodies (e.g., 182) of respective rams (e.g., 178) and corresponding portions of respective first bores (e.g., 158) have non-circular cross-sections, such non-circular cross-sections may inhibit axial rotation of the respective rams relative to the respective first bores. In the depicted embodiment, first end 186 of body 182 has a maximum radius 202 (e.g., a transverse distance measured from a center of the body to an exterior surface of the body) that is substantially equal to one half of maximum transverse dimension 194 of the body. In at least this way, first end 186 of body 182 may facilitate proper alignment of and/or mitigate binding between ram 178 and first bore 158 (e.g., as ram 178 is moved between the first position and the second position).

[0063] In the embodiment shown, first end 186 of body 182 defines one or more grooves 206, which may be configured to allow fluid communication through first bore 158 and past first end 186. In this embodiment, each of one or more grooves 206 is linear (e.g., each of the one or more grooves is defined by faces that are substantially planar); however, in other embodiments at least one of one or more grooves (e.g., 206) of a respective ram (e.g., 178) may be non-linear, helical, and/or the like. In this embodiment, body 182 defines a neck portion 210 between first end 186 and second end 188 (e.g., a portion of the body between the first end and the second end that has a reduced transverse dimension relative to maximum transverse dimension 194). In the depicted embodiment, neck portion 210 of body 182 may be configured to enhance fluid communication between interior volume 86 and first and second bores, 158 and 162, respectively (e.g., when diaphragm 94 is punctured by ram 178) (e.g., by increasing a flow volume defined between ram 178 and body 182).

[0064] However, in some embodiments, at least one of respective one or more reservoirs (e.g., 46) may not be sealed (e.g., by a diaphragm 94), and an opening mechanism (e.g., 150) corresponding to the at least one reservoir may be omitted (e.g., and fluid communication with an interior volume 86 of the at least one reservoir may be controlled instead via one or more valves, such as, for example, an isolation valve 102).

[0065] For example, some embodiments of the present methods for actuating a subsea hydraulically actuated device (e.g., 14) comprise unsealing a sealed outlet (e.g., outlet 90, sealed by a diaphragm 94) of a subsea reservoir (e.g., 46a, accumulator 46b, and/or accumulator 46c), the reservoir defining an interior volume (e.g., 86, 110, and/or 130) in fluid communication with the outlet, the interior volume containing an internal pressure that is lower than a pressure of a subsea environment outside of the reservoir, and placing the outlet of the reservoir into fluid communication with a first port (e.g., 18 or 22) of the hydraulically actuated device. In some methods, unsealing the sealed outlet of the subsea reservoir comprises puncturing a seal (e.g., diaphragm 94) of the reservoir. Some methods comprise placing a second port (e.g., 18 or 22, but not the first port) of the hydraulically actuated device into fluid communication with a pressure source.

[0066] Some embodiments of the present methods for actuating a subsea hydraulically actuated device (e.g., 14) comprise selecting a first port (e.g., 18 or 22) from at least two ports (e.g., 18 and 22) of the hydraulically actuated device and placing the selected first port into fluid communication with an interior volume (e.g., 86, 110, and/or 130) of a subsea reservoir (e.g., 46a, accumulator 46b, and/or accumulator 46c), the interior volume containing an internal pressure that is lower than a pressure of a subsea environment outside of the reservoir. Some methods comprise placing a second port (e.g., 18 or 22, but not the first port) of the at least two ports of the hydraulically actuated device into fluid communication with a pressure source. Some methods comprise selecting a second port (e.g., 18 or 22, but not the first port) from the at least two ports of the hydraulically actuated device and placing the selected second port into fluid communication with the interior volume of the subsea reservoir. Some methods comprise placing the selected first port into fluid communication with a pressure source.

[0067] The above specification and examples provide a complete description of the structure and use of illustrative embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, elements may be omitted or combined as a unitary structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments.

ALTERNATIVE OR ADDITIONAL DESCRIPTIONS OF ILLUSTRATIVE

EMBODIMENTS

[0068] The following alternative or additional descriptions of features of one or more embodiments of the present disclosure may be used, in part and/or in whole and in addition to and/or lieu of, some of the descriptions provided above.

[0069] Some embodiments of the present systems comprise: a bank of accumulators, wherein said bank of accumulators comprises at least two hydraulic accumulators fluidically connected together and wherein the pressure within the hydraulic accumulators is less than ambient subsea pressure, at least one manifold valve, and at least one BOP ram fluidically connected to said bank of accumulators through the at least one manifold valve, wherein the at least one manifold valve actuates to expose the at least one BOP ram to ambient subsea pressure and open the connection to the bank of accumulators.

[0070] Some embodiments comprise ram chambers with dual ports. Some embodiments comprise two-way valves fluidically connected to each port. Some embodiments comprise hydraulically-piloted valves. In some embodiments, the hydraulically-piloted valves are solenoid-actuated. Some embodiments comprise servo-electric actuated valves.

[0071 ] Some embodiments comprise bladder-type accumulators. Some embodiments comprise piston-type accumulators. Some embodiments comprise pressure-compensated accumulators. Some embodiments comprise barrier-less tanks. In some embodiments, the bank of accumulators is ROV-retrievable. In some embodiments, the bank of accumulators is mounted directly to a LMRP/BOP stack. Some embodiments comprise multiple banks of accumulators. [0072] In some embodiments, the system is powered by an electrical power source. In some embodiments, an electrical umbilical connects the system to the electrical power source. Some embodiments comprise a battery for back-up power.

[0073] Some embodiments comprise at least one sensor. Some embodiments comprise at least one pressure transducer. Some embodiments comprise at least one thermocouple. Some embodiments comprise at least one position sensor.

* * *

[0074] The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) "means for" or "step for," respectively.

Claims

A system for actuating a subsea hydraulically actuated device, the system comprising: one or more subsea reservoirs, each comprising:

a body defining an interior volume configured to contain an internal pressure that is lower than a pressure of a subsea environment outside of the body, the body defining an outlet in fluid communication with the interior volume; where the outlet is selectively sealed; and

a hydraulic power delivery system comprising:

a rigid sliding member configured to unseal the outlet of at least one of the one or more reservoirs; and

one or more subsea valves;

where the one or more subsea valves are configured to alternatively allow fluid communication between the outlet of the at least one of the one or more reservoirs and a first port of the hydraulically actuated device or a second port of the hydraulically actuated device.

2. A system for actuating a subsea hydraulically actuated device, the system comprising: one or more subsea reservoirs, each comprising:

a hydraulic power delivery system comprising:

one or more subsea valves;

where the one or more subsea valves are configured to selectively allow fluid communication between the outlet of the at least one of the one or more reservoirs and a first port of the hydraulically actuated device.

3. The system of claim 2, where:

the outlet of the at least one of the one or more reservoirs comprises a diaphragm; and the rigid sliding member is configured to puncture the diaphragm to unseal the outlet of the at least one of the one or more reservoirs.

4. The system of claim 3, where the rigid sliding member comprises:

a ram slidably disposed within a bore and movable between a first position and a second position, the ram configured to puncture the diaphragm as the ram is moved between the first position and the second position;

where fluid communication between the bore and the outlet is permitted when the ram is in the second position. 5. The system of any of claims 2-4, where the one or more subsea valves are configured to alternatively allow fluid communication between the outlet of the at least one of the one or more reservoirs and the first port of the hydraulically actuated device or a second port of the hydrdulically actuated device. A system for actuating a subsea hydraulically actuated device, the system comprising: one or more subsea reservoirs, each comprising a body defining an interior volume configured to contain an internal pressure that is lower than a pressure of a subsea environment outside of the body, the body defining an outlet in fluid communication with the interior volume; and

a hydraulic power delivery system comprising:

one or more subsea valves;

where the one or more subsea valves are configured to alternatively allow fluid communication between the outlet of at least one of the one or more reservoirs and a first port of the hydraulically actuated device or a second port of the hydraulically actuated device.

The system of claim 6, where:

the outlet of the at least one of the one or more reservoirs is selectively sealed; and the hydraulic power delivery system comprises a rigid sliding member configured to unseal the outlet of the at least one of the one or more reservoirs.

The system of claim 7, where:

The system of claim 8, where the rigid sliding member comprises:

where fluid communication between the bore and the outlet is permitted when the ram is in the second position.

10. The system of any of 5-9, where:

the hydraulically actuated device comprises a blowout preventer (BOP);

the first port comprises an open port; and

the second port comprises a close port. 11. The system of any of 5-10, where the one or more subsea valves are configured to selectively allow fluid communication between a pressure source and the second port of the hydraulically actuated device. 12. The system of claim 11, where the one or more subsea valves comprises:

a third two-way valve configured to selectively allow fluid communication between the pressure source and the second port of the hydraulically actuated device; and a fourth two-way valve configured to selectively allow fluid communication between the outlet of the at least one of the one or more reservoirs and the second port of the hydraulically actuated device. 13. The system of claim 11, where the one or more subsea valves comprises a second three- way valve configured to:

selectively allow fluid communication between the pressure source and the second port of the hydraulically actuated device; and

selectively allow fluid communication between the outlet of the at least one of the one or more reservoirs and the second port of the hydraulically actuated device. 14. The system of any of claims 2-13, where the one or more subsea valves are configured to selectively allow fluid communication between a pressure source and the first port of the hydraulically actuated device. 15. The system of claim 14, where the one or more subsea valves comprises:

a first two-way valve configured to selectively allow fluid communication between the pressure source and the first port of the hydraulically actuated device; and a second two-way valve configured to selectively allow fluid communication between the outlet of the at least one of the one or more reservoirs and the first port of the hydraulically actuated device.

16. The system of claim 14, where the one or more subsea valves comprises a first three-way valve configured to:

selectively allow fluid communication between the pressure source and the first port of the hydraulically actuated device; and

selectively allow fluid communication between the outlet of the at least one of the one or more reservoirs and the first port of the hydraulically actuated device. 17 The system of any of claims 11-16, where the pressure source comprises sea water from a subsea environment. 18. The system of any of claims 11-17, where the pressure source comprises a subsea pump. 19. The system of any of claims 11-18, where the pressure source comprises a hydraulic power unit.

20. The system of any of claims 2-19, where at least one of the one or more reservoirs comprises an accumulator.

21. The system of claim 20, where the accumulator comprises a piston-type accumulator.

22. The system of claim 20, where the accumulator comprises a bladder-type accumulator.

23. The system of any of claims 2-22, where the one or more reservoirs comprises two or more reservoirs.

24. The system of any of claims 2-23, where the one or more reservoirs are coupled to a BOP stack.

25. The system of any of claims 2-24, where the one or more reservoirs are configured to be retrievable by a remotely-operated underwater vehicle (ROV).

26. The system of any of claims 2-25, where at least one of the one or more subsea valves comprises a hydraulically piloted subsea valve.

27. The system of any of claims 2-26, where at least one of the one or more subsea valves comprises an electrohydraulic servo valve.

28. The system of any of claims 2-27, where the one or more subsea valves are coupled to a manifold.

29. The system of any of claims 2-28, comprising a battery configured to supply electrical power to the hydraulic power delivery system.

30. The system of any of claims 2-29, comprising one or more sensors configured to capture data indicative of at least one of pressure, flow rate, and temperature of hydraulic fluid within the hydraulic power delivery system.

31. A method for actuating a subsea hydraulically actuated device, the method comprising: unsealing a sealed outlet of a subsea reservoir, the reservoir defining an interior volume in fluid communication with the outlet, the interior volume containing an internal pressure that is lower than a pressure of a subsea environment outside of the reservoir; and

placing the outlet of the reservoir into fluid communication with a first port of the hydraulically actuated device.

32. The method of claim 31, where unsealing the sealed outlet of the subsea reservoir comprises puncturing a seal of the reservoir.

33. The method of claim 31 or 32, comprising:

placing a second port of the hydraulically actuated device into fluid communication with a pressure source.

34. A method for actuating a subsea hydraulically actuated device, the method comprising: selecting a first port from at least two ports of the hydraulically actuated device; and placing the selected first port into fluid communication with an interior volume of a subsea reservoir, the interior volume containing an internal pressure that is lower than a pressure of a subsea environment outside of the reservoir.

35. The method of claim 34, comprising placing a second port of the at least two ports of the hydraulically actuated device into fluid communication with a pressure source.

36. The method of claim 35, comprising:

selecting a second port from the at least two ports of the hydraulically actuated device; and

placing the selected second port into fluid communication with the interior volume of the subsea reservoir

37. The method of claim 36, comprising placing the selected first port into fluid communication with a pressure source.