Distributed subsea power grid

Abstract

An system, including a first subsea electric subsystem, a first energy storage device associated with and directly coupled to the first subsea electric subsystem, a second subsea electric subsystem, a second energy storage device associated with and directly coupled to the second subsea electric subsystem, and a conduit coupled to the first energy storage device and coupled to the second storage device, wherein the first energy storage device is indirectly coupled to the second energy storage device via the conduit.

Description

DISTRIBUTED SUBSEA POWER GRIDCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Non-Provisional Application claiming priority to U.S. Provisional Patent Application No. 63 / 604,880, entitled “Distributed Subsea Power Grid,” filed November 30, 2023, which is herein incorporated by reference.BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it may be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] There is growing interest in using subsea production systems that are fully electric instead of electrohydraulic. However, this may entail changes be made to the production system equipment in order to support a fully electric system. For example, hydraulic supply lines used in traditional hydroelectric systems would no longer be utilized, thus allowing for smaller umbilical diameters. Likewise, electric actuators, for example, would replace hydraulic ones and subsea energy storage systems would replace subsea hydraulic accumulators. The present disclosure relates generally to the subsea energy storage system that may be used with an electric production system.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The subject disclosure is further described in the following detailed description, and the accompanying drawings and schematics of non-limiting embodiments of the subject disclosure. The features depicted in the figures are not necessarily shown to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form, and some details of elements may not be shown in the interest of clarity and conciseness. These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0005] FIG. 1 shows interlinked subsea energy storage units (SESUs) on a tree or manifolds according to one or more aspects of the present disclosure;

[0006] FIGS. 2-4 show various interconnections between the SESUs according to one or more aspects of the present disclosure;

[0007] FIG. 5 shows interlinked SESUs configured in a power-sharing arrangement according to one or more aspects of the present disclosure;

[0008] FIG. 6 shows redundant power grids according to one or more aspects of the present disclosure; and

[0009] FIGS. 7-9 show a simplified SESU power grid connection according to one or more aspects of the present disclosure.DETAILED DESCRIPTION

[0010] One or more specific embodiments of the present disclosure will be described below. The particulars shown herein are by way of example, and for purposes of illustrative discussion of the embodiments of the subject disclosure only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the subject disclosure. In this regard, no attempt is made to show structural details of the subject disclosure in more detail than is necessary for the fundamental understanding of the subject disclosure, the description taken with the drawings making apparent to those skilled in the art how the several forms of the subject disclosure may be embodied in practice. Additionally, to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0011] When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” Also, any use of any form of the terms “connect,” “engage,” “couple,” “attach,” or any other term describing an interaction betweenelements is intended to mean either an indirect or a direct interaction between the elements described. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. The use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience but does not require any particular orientation of the components.

[0012] Certain terms are used throughout the 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.

[0013] Generally, for electrohydraulic subsea production systems, the power needed to actuate valves is supplied through an umbilical. However, in some circumstances, the power supplied through the umbilical in an electrohydraulic subsea production system is insufficient and / or otherwise costly to power an electric system subsea production system. For example, transmitting sufficient power through the umbilical of an electrohydraulic subsea production to actuate electric actuators in the closing of large bore valves in an electric subsea production system can be costly. Accordingly, it may be advantageous to have power sources located subsea. Similar to accumulators used for hydraulic actuators, a subsea energy storage unit (SESU) may power electric actuators to open and close a valve in an electric subsea production system. These SESUs can include a power storage device (e.g., a battery) as well as associated circuitry utilizing the charging and discharging of the power storage device. In this manner, use of the SESUs subseacan operate to overcome the potential issue of insufficient power being able to be provided at particular times (e.g., during a shut-down operation) via the umbilical while reducing costs associated with umbilical only powering of components in an electric subsea production system.

[0014] This SESU may be a single central SESU or a decentralized SESU system with individual SESUs attached to each component (for example electric actuators). The SESU may power all subsea components in the event of a loss of power. This can increase the importance of the SESU with respect to the design of the electric subsea production system, since it operates as an important component in the powering the actuation system and any other components. Moreover, in some embodiments, the capacity of the SESU should be sufficient to provide the power utilized for closing all critical valves, in the event of a shutdown. Due to this importance of the SESU, including powering systems that meet standards and requirements for subsea production systems (e.g., the American Petroleum Institute Standard 17F for subsea production control systems) can be challenging. For example, the storage (e.g., battery) should have sufficient capacity to power multiple (e.g., three) full tree cycles. Additionally, there may be additional power consumers, for example, an electric choke, electric downhole safety valve and sensors, etc. that drive a relatively large SESU capacity. The present disclosure describes a distributed power concept, for example, on system level to allow for implementation of an electric subsea production system.

[0015] The disclosed system herein incorporates a subsea energy storage system (e.g., a distributed power grid) that may be used with an electric production system. The subsea energy storage can include a SESU that can operate, for example, to open and close one or more valves or other components in a unit of subsea equipment. This SESU can operate as a single SESU in some embodiments. Alternatively, the SESU can be part of a decentralized power grid (i.e., adistributed power grid) that includes additional individual SESUs of units of the subsea equipment coupled to one another. Linking of the SESUs can operate to create the decentralized power grid (i.e., a distributed power grid). In some embodiments, the SESUs can be operated to balance power demand on the decentralized power grid through, for example, rerouting of power to a particular unit of need from other units in the decentralized power grid. In other embodiments, charging of SESUs can also be accomplished (i.e., SESU to SESU charging). This can be advantageous if, for example, there is high demand forecasted for a particular unit of the electric subsea production system. The SESU associated with that unit may be charged by other SESUs not forecasted to be in use and / or having low demand at that same time.

[0016] Referring now to FIG. 1, an electric production system 100 is illustrated. The electric production system 100 includes topside equipment 102, such as a master control station (MCS) and / or an electrical power unit (EPU). The MCS may, for example, operate as a controller or a processor that operates to execute one or more programs that include computer-executable instructions and associated data that may be configured to perform various functions of the embodiments described herein. In certain embodiments, to perform these various functions, the one or more programs that include computer-executable instructions are stored on a non-transitory machine medium, such as memory (e.g., semiconductor memory devices such as dynamic or static random access memories (DRAMs or SRAMs), erasable and programmable read-only memories (EPROMs), electrically erasable and programmable read-only memories (EEPROMs) and flash memories, etc.) and / or storage (e.g., solid state drives, magnetic disks such as fixed, floppy and removable disks; other magnetic media including tape; optical media such as compact disks (CDs) or digital video disks (DVDs); or other types of storage devices),

[0017] As noted above, the topside equipment 102 can also include an EPU that operates to distribute electrical power. For example, the EPU can receive an electrical supply from, for example, one or more generators, make desired adjustments to the received electrical supply through, for example, fdtering, regulating, amplifying, etc. the received power into a desired power signal having predetermined characteristics, such as voltage, current, and / or frequency. The EPU can additionally transmit the adjusted power to subsea equipment for use therein. In some embodiments, the topside equipment 102 can disposed on or be a part of, for example, a drill rig, a production platform, or another offshore vessel or platform.

[0018] As illustrated, the topside equipment 102 can be coupled to subsea equipment 104 via, for example, an umbilical 106. As illustrated, the subsea equipment 104 can be electric subsea equipment that operates without hydraulic components (e.g., components that are controlled by hydraulics or hydraulic control signals, for example, hydraulic actuators, etc.). For example, FIG. 1 illustrates the subsea equipment 104 as including an electric Christmas tree (eXT) 108, a manifold 110, and boosting components 112 (i.e., a boosting station). The eXT 108 generally operates to control and / or monitor production of hydrocarbons from and / or injection of fluids into a subsea well without the use of hydraulic components (i.e., components that are controlled via hydraulics). The eXT 108 can include, for example, a SESU 114, an electric Subsea Control Module (eSCM) 116, and flow control components 118. The eSCM 116 of the eXT 108 can provide control and / or monitoring functions of the eXT 108 and / or equipment installed therein. In operation, the eSCM 116 can operate to communicate with the topside equipment 102, for example, the MCS to provide actuation and position monitoring of valves of the flow control components 118, monitoring of pressures, temperatures and flow rates measured in or by the eXT 108, etc. The eSCM 116 may, for example, operate as a controller or a processor that operates toexecute one or more programs that include computer-executable instructions and associated data that may be configured to perform various functions of the embodiments described herein. In certain embodiments, to perform these various functions, the one or more programs that include computer-executable instructions are stored on a non-transitory machine medium, such as memory (e g., semiconductor memory devices such as dynamic or static random access memories (DRAMs or SRAMs), erasable and programmable read-only memories (EPROMs), electrically erasable and programmable read-only memories (EEPROMs) and flash memories, etc.) and / or storage (e.g., solid state drives, magnetic disks such as fixed, floppy and removable disks; other magnetic media including tape; optical media such as compact disks (CDs) or digital video disks (DVDs); or other types of storage devices).

[0019] As illustrated, the eXT 108 can further include a SESU 114. The SESU 114 can include a power storage device (e.g., a battery) as well as associated circuitry utilizing the charging and discharging of the power storage device. In some embodiments, the SESU 116 can be disposed in the eXT 108 (i.e., inside an enclosure of or otherwise a part of the eXT 108). In other embodiments, the SESU 114 can be external to the eXT 108 and electrically coupled to the eXT 108.

[0020] The eXT 108 can additionally include the flow control components 118. In some embodiments, these flow control components include electrical actuators that operate to open and close valves of the eXT 108 as directed by the eSCM 116.

[0021] Other components can be part of the subsea equipment 104. For example, a manifold 110 can be utilized. The manifold 110 can operate to divert and / or route the flow of hydrocarbons, for example, from the eXT 108 into additional flowlines to allow for their transfer to the topside. The manifold 110 can include an eSCM 116, similar that described above withrespect to the eXT 108, that operates to provide control and / or monitoring functions of the manifold 110 and / or equipment installed therein. In operation, the eSCM 116 can operate to communicate with the topside equipment 102, for example, the MCS to provide actuation and position monitoring of valves of the flow control components 118, etc.

[0022] As additionally illustrated, the manifold 110 can further include an SESU 114. The SESU 114 can include a power storage device (e.g., a battery) as well as associated circuitry utilizing the charging and discharging of the power storage device. In some embodiments, the SESU 114 can be disposed in the manifold 110 (i.e., inside an enclosure of or otherwise a part of the manifold 110). In other embodiments, the SESU 114 can be external to the manifold 1 lOand electrically coupled to the manifold 110.

[0023] The manifold 110 can additionally include the flow control components 118. In some embodiments, these flow control components include electrical actuators that operate to open and close valves of the manifold 110 as directed by the eSCM 116.

[0024] The subsea equipment 104 can also include boosting components 112. The boosting components 112 can include one or more pumps (e.g., electric pumps) and can operate to drive fluids within the system subsea equipment. The boosting components 112 can include an eSCM 116, similar that described above with respect to the eXT 108, that operates to provide control and / or monitoring functions of the boosting components 112 and / or equipment installed therein. In operation, the eSCM 116 can operate to communicate with the topside equipment 102, for example, the MCS to provide actuation and position monitoring of valves of the flow control components 118, etc.

[0025] As additionally illustrated, the boosting components 112 can further include anSESU 114. The SESU 114 can include a power storage device (e.g., a battery) as well as associated circuitry utilizing the charging and discharging of the power storage device. In some embodiments, the SESU 114 can be disposed in the boosting components 112 (i.e., inside an enclosure of or otherwise a part of the boosting components 112). In other embodiments, the SESU 114 can be external to the boosting components 112 and electrically coupled to the boosting components 112.

[0026] The boosting components 112 can additionally include the flow control components 118. In some embodiments, these flow control components include electrical actuators that operate to open and close valves of the manifold 110 as directed by the eSCM 116.

[0027] As described herein, the components of the eXT 108, the manifold 110, and the boosting components 112 are electrical components and do not include hydraulicly controlled components. As noted above, the topside equipment 102 can be coupled to the subsea equipment 104 via, for example, an umbilical 106. This umbilical 106 can provide a power signal (i.e., electrical power from the EPU) as well as control signals (i.e., from the MCS) to the eXT 108, the manifold 110, and the boosting components 112. The umbilical 106 can operate to provide power and control signals that are electrical only, i.e., no hydraulics are provided via the umbilical 106.

[0028] Additionally, a conduit 120 can be employed as part of the subsea equipment 104. The conduit 120 can be, for example, an electrical path, wiring, an enclosure housing wiring, or the like and operates to route power between the components of the subsea equipment. In some embodiments, the umbilical 106 (or the power lines therein) can be coupled to the conduit 120 to allow for power to flow to the SESUs 114 of the eXT 108, the manifold 110, and the boosting components 112. However, as will be discussed in greater detail below, the conduit 120 canadditionally and / or alternatively be utilized as a pathway to connect the SESUs 114 of the eXT 108, the manifold 110, and the boosting components 112, for example, to allow power to flow therebetween and / or to the respective eXT 108, the manifold 110, and the boosting components 112 as part of a power distribution infrastructure.

[0029] In this manner, FIG. 1 illustrates an example of interlinked SESUs 114 on the eXT 108 (i.e., a tree), manifold 110, and boosting components 112. Linking the SESUs 114 creates an independent and decentralized subsea power grid. This decentralization has many advantages. The SESUs 114 could balance the power demand by moving required power to the unit where it is used. This increases the uptime of the unit where the power is demanded. For example, the start-up of an eXT 108 after a shutdown could be accelerated from almost a day to a few minutes. Creating a subsea power grid also can increase the uptime of the electric production system 100 in case of a failure. If a SESU 114 on an eXT 108 fails, another SESU 114 located, for example, on a manifold 110 close by could provide power to be used in the operation of the eXT 108 (or vice versa). This also allows for production, for example, under maintenance operations.

[0030] If a SESU 114 on a manifold 110 or any other unit needs to be replaced, the power to continue operation could be sourced from any other SESU 114. The electric production system 100 would no longer have to shut down. Additionally, SESU 114 maintenance like cyclic depletion for recalibration purposes would not have an impact on the unit it is installed on. Furthermore, in case of a SESU 114 depletion, that SESU 114 could be recharged from other SESUs 114. This could be used to reduce the charging power / stress required from the umbilical 106, even further reducing the size of the umbilical 106. Thus, for example, charging from the umbilical 106 could be continued with high demands being covered by the SESUs 114 operating as distributed power sources in the power distribution infrastructure.

[0031] In this manner, decentralization and interlinked SESUs 114 supports moving more functionality from the platform topside to subsea. Interlinking the SESUs 114 creates an independent distributed power grid. Referring now to FIGS. 2-4, various interconnections between the SESUs 114 are shown as examples of distributed power grids of the subsea equipment 104. For example, FIG. 2 illustrates a distributed power grid 122 in which the conduit 120 is configured as a power rail. FIG. 3 illustrates a distributed power grid 124 as a circular grid and FIG. 4 illustrates a distributed power grid 126 as a star shaped grid. FIGS. 2-4 are provided as examples of manners in which to dispose the SESUs 114 as a distributed power grid 122, a distributed power grid 124, and a distributed power grid 126. However, it should be noted that additional and / or alternative configurations may be employed in distributing the SESUs 114 to create a decentralized power grid. Indeed, the interconnections between the SESUs 114 may be configured in any other shape or orientation to provide power to the components of the subsea equipment 104 (i.e., the subsea production system).

[0032] In some embodiments, the choice of the shape / component distribution selected may be driven by the locations of the manifold 110, eXT(s) 108, boosting components 112, and / or any other equipment utilizing power as part of the subsea equipment. Additionally, it should be appreciated that power can selectively flow bidirectionally in the conduit 120 between the SESUs 114, so that, for example, if one portion of the conduit 120 is damaged, power can still flow through the remaining portions of the conduit between SESUs 114.

[0033] The SESUs 114 power, for example, the valves, eSCM 116, sensors, etc. on an eXT108, manifold 110, or boosting components 112, respectively. However, by connecting the SESUs114 into a decentralized power grid, for example, as distributed power grid 122, distributed power grid 124, or distributed power grid 126, the SESUs 114 from one subsea unit can be used to poweranother subsea unit of the subsea equipment 104. In some embodiments, the umbilical 106 charges directly into the distributed power grid 122, the distributed power grid 124. In this situation, an umbilical termination assembly (UTA) connecting the umbilical 106 to the units of the subsea equipment 104 (e.g., eXT 108, manifold 110, and / or boosting components 112) can be omitted. However, as illustrated in FIG. 4, the umbilical 106 can instead be coupled to the distributed power grid 126 for charging via a unit, for example, an eXT 108 (e.g., Tree 3) or via a UTA coupled to the eXT 108. In other embodiments, the conduit 120 can be part of a UTA that is utilized. Regardless of the grid configuration, a SESU 114 failure will not interrupt the charging process, since power to any individual unit of the distributed power grid 122, the distributed power grid 124, and / or the distributed power grid 126 need not solely be provided via the umbilical 106, but can instead be rerouted from other SESUs 114 of the distributed power grid 122, the distributed power grid 124, and / or the distributed power grid 126, as will be described in greater detail below.

[0034] Turning now to FIG. 5, interlinked SESUs 114 configured in a power-sharing arrangement are shown as part of the distributed power grid 124. In some embodiments, management of charge and discharge can be undertaken topside via, for example the MCS. That is, the umbilical 106 can charge the individual SESUs 114, for example, in parallel and / or in a predetermined order (which can be serial). Once charged, and an increased power need is recognized from a single SESU 114, the increase in power to that SESU 114 can be provided from the distributed power grid 124. In some embodiments, the increase in power can be selectively transmitted from any one individual SESU 114 (e.g., from the SESU 114 of the boosting components 112 when, for example, the flow control components 118 of the boosting components 112 are not yet activated but the SESU 114 of the boosting components 112 is charged), from twoor more SESUs 114 of the distributed power grid 124, from a single SESU 1 14 and the umbilical106, and / or from two or more SESUs 114 of the distributed power grid 124 and the umbilical 106.

[0035] Thus, if there is a high local demand on one of the interlinked SESUs 114 (e.g., Tree 2), the idle or fully charged SESUs 114 on other components (e.g., Tree 3, Tree 4, Manifold 110) with or without umbilical 106 may send power to the SESU 114 of eXT 108 (e.g., Tree 2) avoid a deep discharge and eventually prevent a shutdown or loss of the subsystem (e.g., a eXT 108, manifold 110, boosting components 112, etc.). The same concept may also apply for a failure in one of the SESUs 114. The remaining SESUs 114 of the distributed power grid 124 may cover the failure and provide the required power at the specific unit. In this manner, the SESUs 114 in FIG. 5 represent a central-SESU and decentral-SESU concept on the eXT 108 or manifold 110 or other subsystems. In some embodiments, the power transmitted to a unit (e.g., to Tree 2) can be evenly split amongst the other units providing power (e.g., each of Tree 3, Tree 4, Manifold 110, and umbilical 106 provide 25% of the power transmitted to Tree 2). In other embodiments, the power transmitted to any one unit (e.g., Tree 2) can be unevenly and selectively provided by some or all of the other units (e.g., Tree 3, Tree 4, and Manifold 110 provide 30% of the power transmitted to Tree 2 and umbilical 106 provides 10% of the power transmitted to Tree 2).

[0036] As illustrated, the umbilical 106 can supply continuous low power to the power grid (i.e., distributed power grid 124). However, the power transmitted may be insufficient to meet demands of an event for a particular SESU 114. Accordingly, the above described process for routing of power to the SESU 114 in need is accomplished. Because subsea actuation is a rare event, the SESUs 114 have sufficient time to fully charge via the power transmitted from the umbilical 106. In some embodiments, the umbilical 106 directly covers the power consumers (i.e., components of the eXT 108, the manifold 110, and the boosting components 112). If this is notneeded, a switch component may be used to control the flow of power from the umbilical 106. In some embodiments, power passes through the SESUs 114 to avoid tripping the power supply feeding into the umbilical 106. Additionally, interchanging between different SESUs 114 reduces the charging stress on the umbilical 106. Additionally, by lowering the power demand on the umbilical 106, the cross section of the power cables inside the umbilical 106 can be reduced, which in turn reduces the diameter of the umbilical 106 relative to an electrohydraulic one.

[0037] The power distribution described above can also be applied in systems with power redundancy. FIG. 6 illustrates a distributed power grid 128 similar to the distributed power grid 124 of FIG. 5. However, the distributed power grid 128 includes two SESUs 114 in each unit of the distributed power grid 128 (i.e., eXT 108, manifold 110, boosting components 112, etc.). Additionally, there can be two conduits 120 each coupled to a particular umbilical 106 (or each coupled to a separate line in one umbilical 106) to generate two power grids. This illustrated configuration allows for failure of one grid (e.g., Grid A) while still allowing the subsea equipment 104 and, accordingly, the electric production system 100, to be brought online via the other grid (e.g., Grid B). The power sharing techniques described above with respect to the distributed power grid 124 of FIG. 5 can be applied to the distributed power grid 128 of FIG. 6. Additionally, one SESU 114 (e.g., SESU A of Tree 2) can be used to power another SESU 114 (e.g., SESU B of Tree 2) in a single unit of the distributed power grid 128. Similarly, one SESU 114 (e.g., SESU A of Tree 2) of a first grid (e.g., Grid A) can be used to power another SESU (e.g., SESU B of Tree3) in another unit of the second grid (e.g., Grid B). In this manner, the redundancy of distributed power grid 128 can be utilized to further expand the ability to provide power to any of the components of the subsea equipment 104.

[0038] Thus, FIG. 6 provides an example in which redundant power grids provided, here a first power grid (e.g., Grid A) and second power grid (e.g., Grid B) are disposed in parallel to provide redundant channels. In some embodiments, one channel balances power on grid A and the other on grid B. The redundancy increases system reliability and availability. However, in some embodiments, the power grid may replace the redundancy. Redundancy makes a system resistant to a single point of failure so that the decentral power grid (e.g., distributed power grid 128) is resistant to single point of failure. Accordingly, redundancy on the power grid level may no longer be needed, since if a SESU 114 fails, the power grid will provide the energy to bring the subsystem in a safe state.

[0039] Referring now to FIGS. 7-9, a portion of a distributed power grid 128 is illustrated to highlight an example of the operation of the distributed power grid 128. As illustrated in FIG. 7, a power grid (i.e., one of Grid A or Grid B) is connected to the input / output of each SESU 114. Along path 138 of each SESU 114 is a switch 130, storage device 132, switch 134, and diode 136. A second path, path 140, is also illustrated as connecting the consumers (e.g., flow control components 118) of each of the eXT 108 and the manifold 110 to a respective grid. It should be noted that, for example, path 140 can be disposed outside of its SESU 114 and that its illustrated configuration is for explanatory purposes only.

[0040] The input of each SESU 114 is connected to the switch 130, which regulates the charging of the storage device 132 (e.g., a battery pack or other electric storage device) as disposed along path 138. The output of the storage device 132 pack is controlled by switch 134. Inclusion of diode 136 prevents power from passing to the output of the storage device 132. In some embodiments, placing each of switch 130 and switch 134 into their closed positions at the same time is prevented. This allows for the storage device 132 to either charge (when switch 130 isclosed) or discharge (when switch 134 is closed). The storage device 132 can be connected back to the grid (e.g., via path 140) to power consumers (e.g., flow control components 118) located in a different unit (e.g., manifold 110) than the unit (e.g., eXT 108) in which the SESU 114 is located (e g., eXT 108). Likewise, the storage device 132 can be connected (e.g., via path 138) to power consumers (e.g., flow control components 118) located in the same unit (e.g., eXT 108) in which the SESU 114 is located.

[0041] In some embodiments, when the storage device 132 is charging via switch 130 being closed, no actuation is taking place and low power consumers are powered by the umbilical 106 in parallel with the charging of the storage device 132. This can be considered the system idle state and is illustrated in FIG. 8.

[0042] If actuation is needed, switch 130 will be opened and switch 134 will be closed. This situation is represented in FIG. 9 and illustrates a SESU 114 (e.g., SESU A of Tree) as powering the consumers (e.g., flow control components 118 of Tree). Additionally and or alternatively, the power from the SESU 114 (e.g., SESU A of Tree) can be transmitted back to the entire subsea grid (e.g., Grid A) for example, to provide power to consumers (e.g., flow control components 118 ofManifold 110) if the SESU 114 (e.g., SESU A of Manifold 110) of another unit (e.g., Manifold 110) is offline. In this manner, FIG. 9 demonstrates a failure scenario. If a SESU 114 (e.g., SESU A on the manifold 110) is inoperable, another SESU 114 (e.g., SESU A on the Tree) can provide the power for any manifold 110 operation. In some embodiments, the failedSESU 114 (e.g., SESU A on the manifold 110) can be isolated, for example, via fail open switches. One or more of the remaining SESUs 114 can be activated to transmit power to the consumers associated with the failed SESU 114 (e.g., SESU A on the manifold 110). The one or more SESUs114 utilized to replace the failed SESU 114 (e g., SESU A on the manifold 110) can be SUSU B of the manifold 110, SESU A of the eXT 108, SESU A of the eXT 108, or any combination thereof.

[0043] The illustrated embodiments can be modified with an alternative switch configuration as needed to provide desired powering flexibility for the distributed power grid 128. In some embodiments, the state in which the storage device 132 inside the SESUs 114 are not charging is relatively short. Thus, once an action (e.g., an actuation) is completed, switch 134 can be opened and switch 130 can be closed. Additionally, if fast recharging is needed, a SESU 114 connected to the same grid (e g., Grid A) could provide the power.

[0044] The embodiment shown in FIG. 9 is a simplified example. Depending on the type of consumers and power demand, the configuration may change. Switches may be added to develop an advanced power distribution upstream of the SESU 114. Power grid requirements can change the input and output structure to the SESU 114. The functionality of the bypass might change slightly but the principle of bypass is generally present to ensure a functional charging and discharging grid concept.

[0045] While the subject disclosure is described through the above embodiments, it will be understood by those of ordinary skill in the art that modification to and variation of the illustrated embodiments may be made without departing from the inventive concepts herein disclosed. Moreover, while some embodiments are described in connection with various illustrative structures, one skilled in the art will recognize that the system may be embodied using a variety of specific structures.

Claims

CLAIMSWhat is claimed is:

1. A system, comprising: a first subsea electric subsystem; a first energy storage device associated with and directly coupled to the first subsea electric subsystem; a second subsea electric subsystem; a second energy storage device associated with and directly coupled to the second subsea electric subsystem; and a conduit coupled to the first energy storage device and coupled to the second energy storage device, wherein the first energy storage device is indirectly coupled to the second energy storage device via the conduit.

2. The system of claim 1, comprising a first switch disposed between the conduit and the first energy storage device.

3. The system of claim 2, wherein the first switch is selectively placed in a closed position in conjunction with a first operating mode to couple the first energy storage device to the conduit to receive power transmitted from the conduit to charge the first energy storage device.

4. The system of claim 3, comprising a second switch disposed between the first energy storage device and power consumer components of the first subsea electric subsystem.

5. The system of claim 4, wherein the second switch is selectively placed in the closed position and the first switch is selectively placed in an open position in conjunction with a second operating mode to couple the first energy storage device to power consumer components of the first subsea electric subsystem to transmit power to the power consumer components from the first energy storage device.

6. The system of claim 5, wherein the second switch is selectively placed in the closed position and the first switch is selectively placed in the open position in conjunction with a third operating mode to couple the first energy storage device to the second energy storage device via the conduit to transmit power to second energy storage device from the first energy storage device.

7. The system of claim 5, wherein the second switch is selectively placed in the closed position and the first switch is selectively placed in the open position in conjunction with a third operating mode to couple the first energy storage device to power consumer components of the second subsea electric subsystem via the conduit to transmit power to the power consumer components of the manifold from the first energy storage device.

8. The system of claim 7, wherein the power consumer components of the first subsea electric subsystem comprise a plurality of electric actuators configured to control actuation of a respective valve or one or more pumps.

9. A method, comprising: receiving power from an umbilical at a first subsea energy storage unit corresponding to a first component of a subsea distributed power grid to charge a first energy storage device of the first subsea energy storage unit; receiving power from the umbilical at a second subsea energy storage unit corresponding to a second component of the subsea distributed power grid to charge a second energy storage device of the second subsea energy storage unit; and selectively connecting the first subsea energy storage unit to provide first power from the first energy storage device to power consumers of the second component of the subsea distributed power grid.

10. The method of claim 9, comprising providing the first power from the first energy storage device to the power consumers of the second component of the subsea distributed power grid when the second subsea energy storage unit is disabled.

11. The method of claim 9, comprising providing the first power from the first energy storage device to the power consumers of the second component of the subsea distributed power grid in parallel with providing second power from the second energy storage device to the power consumers of the second component of the subsea distributed power grid.

12. The method of claim 9, comprising closing a first switch coupled to an input of the first energy storage device of the first subsea energy storage unit when receiving power from the umbilical to charge the first energy storage device of the first subsea energy storage unit.

13. The method of claim 12, comprising opening the first switch and closing a second switch coupled to an output of the first energy storage device of the first subsea energy storage unit when providing the first power from the first energy storage device to the power consumers of the second component of the subsea distributed power grid.

14. The method of claim 12, comprising opening the first switch and closing a second switch coupled to an output of the first energy storage device of the first subsea energy storage unit when providing second power from the first energy storage device to power consumers of the first component of the subsea distributed power grid.

15. The method of claim 9, comprising closing a first switch coupled to an input of the second energy storage device of the second subsea energy storage unit when receiving power from the umbilical to charge the second energy storage device of the second subsea energy storage unit.

16. The method of claim 15, comprising opening the first switch and closing a second switch coupled to an output of the second energy storage device of the second subsea energy storage unit to provide second power from the second energy storage device to the power consumers of the second component in parallel with the first power.

17. The method of claim 15, comprising opening the first switch and opening a second switch coupled to an output of the second energy storage device of the second subsea energy storage unitwhen providing the first power from the first energy storage device to the power consumers of the second component.

18. A system, comprising: a conduit configured to transmit power across a subsea distributed power grid; a first subsea energy storage unit corresponding to a first component of the subsea distributed power grid, wherein the first subsea energy storage unit comprises a first energy storage device coupled to first power consumers of the first component, wherein the first subsea energy storage unit is coupled to the conduit; and a second subsea energy storage unit corresponding to a second component of the subsea distributed power grid, wherein the second subsea energy storage unit comprises a second energy storage device coupled to second power consumers of the second component, wherein the second subsea energy storage unit is coupled to the conduit, wherein the first energy storage device is configured to selectively provide first power to power consumers of the second component.

19. The system of claim 18, wherein the wherein the first energy storage device is configured to selectively provide first power to the second power consumers of the second component in parallel with the second energy storage device providing second power to the second power consumers of the second component.

20. The system of claim 18, wherein the wherein the second energy storage device is configured to selectively provide second power to the first power consumers of the first component.

Images