Geothermal power systems and methods for subsea systems

A system includes a subsea geothermal power system. The subsea geothermal power system includes a separator configured to separate a well fluid from a hydrocarbon well into a first fluid flow and a second fluid flow. The subsea geothermal power system also includes a geothermal power plant coupled to the separator. The geothermal power plant is configured to receive thermal energy from the second fluid flow and convert the thermal energy into at least one of electrical energy and mechanical energy. The separator is at least partially powered by the at least one of electrical energy and mechanical energy produced by the subsea geothermal power system.

BACKGROUND

The subject matter disclosed herein relates to one or more geothermal power systems disposed in a subsea system.

A subsea system used for extracting hydrocarbons includes one or more electrically-powered subsystems, including a manifold, a tree, a pump station, and the like. These electrically-powered subsystems are conventionally electrically coupled to a power station, which is powered via one or more electrical cables (e.g., umbilical cables) that electrically couple the power station to a surface platform. Due to the amount of power that is transmitted through these electrical cables to the power station and the shielding used for protecting the electrical cables from the surrounding water, the manufacturing cost of these electrical cables is substantial. Additionally, due to the length of the cable and other factors, loss of power through the electrical cables is known to occur. Accordingly, a need exists for at least lowering the manufacturing cost of these electrical cables and mitigating the likelihood of loss of power transmission.

SUMMARY

In an embodiment, a system includes a subsea geothermal power system. The subsea geothermal power system includes a separator configured to separate a well fluid from a hydrocarbon well into a first fluid flow and a second fluid flow. The subsea geothermal power system also includes a geothermal power plant coupled to the separator. The geothermal power plant is configured to receive thermal energy from the second fluid flow and convert the thermal energy into at least one of electrical energy and mechanical energy. The separator is at least partially powered by the at least one of electrical energy and mechanical energy produced by the subsea geothermal power system.

In another embodiment, a system includes a subsea retrieval module. The subsea retrievable module includes a separator configured to separate a well fluid from a hydrocarbon well into a hydrocarbon flow and a water flow. The subsea retrievable module also includes a geothermal power plant coupled to the separator. The geothermal power plant includes a fluid circuit having a first heat exchanger configured to transfer thermal energy from the water flow to a thermal fluid circulating in the fluid circuit, and a turbine driven by the thermal fluid. The separator is at least partially powered by at least one of mechanical energy generated by the turbine and electrical energy generated by an electrical generator driven by the turbine of the geothermal power plant.

In another embodiment, a method includes controlling, via a processor, a separator of a geothermal power system to separate a well fluid from a hydrocarbon well into a first fluid flow and a second fluid flow. The method also includes controlling, via a processor, a geothermal power plant of the geothermal power system to receive thermal energy from the second fluid flow. The method also includes controlling, via the processor, the geothermal power plant to convert the thermal energy into at least one of electrical energy and mechanical energy. The method also includes controlling, via the processor, the geothermal power system to power the separator using the at least one of electrical energy and mechanical energy.

DETAILED DESCRIPTION

As used herein, the term “coupled” or “coupled to” may indicate establishing either a direct or indirect connection (e.g., where the connection may not include or include intermediate or intervening stations between those coupled), and is not limited to either unless expressly referenced as such. The term “set” may refer to one or more items. Wherever possible, like or identical reference numerals are used in the figures to identify common or the same elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale for purposes of clarification.

The present disclosure is generally directed toward one or more one or more geothermal power systems that are distributed throughout a subsea system that may be used to produce power for use by the subsea system and/or a surface platform. In particular, the disclosed embodiments may be used for powering one or more trees (e.g., Christmas tree, frac tree, production tree, etc.) coupled to one or more wells throughout the field (e.g., a hydrocarbon field), one or more field extensions, the controller, the pump station, the manifold, subsea boosting, subsea compression, pipe heating, or a combination thereof. In certain embodiments, power produced by the one or more geothermal power systems may be sent to a surface platform via an electrical cable (e.g., umbilical cable). It may be appreciated that a geothermal power system that includes a plurality of geothermal wells may produce sufficient power to eliminate the three phase power cable portion of the electrical cables connecting the surface platform, thereby reducing the manufacturing cost of the electrical cable. A geothermal power system having a plurality of geothermal wells may also eliminate the traditional fuel (e.g., diesel fuel) that may be used for powering pumps and/or separators. Additionally, the one or more geothermal power systems may be able to mitigate the chance of losing power due to a loss of power transmission through the electrical cable. The use of one or more geothermal power systems disposed throughout the subsea system also produces zero carbon emissions, thereby offsetting and potentially reducing the amount of carbon emissions produced for powering various stations of the subsea system.

With the foregoing in mind,FIG.1is a schematic view of a subsea system10with electrical cables12(e.g., umbilical cables) used for transmitting information and primary electrical power for various subsea stations (e.g., actuators, sensors, etc.). The subsea system10may include a subsea hydrocarbon production system configured to extract oil or gas from a subterranean reservoir, a subsea fluid injection system configured to inject fluid (e.g., liquid or gas) into a subterranean reservoir, or any other subsea system associated with subterranean reservoirs. For example, the subsea fluid injection system may include a subsea gas, water, and/or carbon dioxide (CO2) injection system. In certain embodiments, the subsea system10may include a subsea tree14coupled to a wellhead16to form a subsea station18configured to extract and/or inject fluids relative to a subterranean reservoir. In certain embodiments, the subsea tree14includes a Christmas tree having a set of valves, spools, and fittings connected to the top of a well to direct and control the flow of formation fluids from the well. An example of the Christmas tree is a production tree, which may be installed after completion of hydraulic fracturing. The subsea tree14may include a frac tree having upper and lower master valves, a flow cross, wing valves, a goat head, and a swap valve, wherein the frac tree is configured to facilitate hydraulic fracturing. However, the subsea tree14may include any type and configuration and trees. The subsea station18may be configured to extract formation fluid, such as oil and/or natural gas, from the sea floor20through the well22. By further example, the subsea station18may be configured to inject CO2into the subterranean reservoir. In some embodiments, the subsea system10may include multiple subsea stations18that extract and/or inject fluids relative to respective wells22.

In embodiments of the subsea system10configured for production, after passing through the subsea tree14, the formation fluid flows through fluid conduits or pipes24to a manifold26(e.g., pipeline manifold or flowline manifold). The manifold26may connect to one or more flowlines28. In some embodiments, the surface platform30may include a floating production, storage, and offloading unit (FPSO) or a shore-based facility. In addition to flowlines28that carry the formation fluid away from the wells22, the subsea system10may include a conduit32that carry production fluid (e.g., hydrocarbons, oil, natural gas, etc.) to the surface platform30.

A conduit32is fluidly connected to the pump station34, which is configured to pump the production fluid from the seabed20to the surface platform30. In some scenarios, the platform30may be located a significant distance (e.g., greater than 100 m, greater than 1 km, greater than 10 km, or greater than 60 km) away from the wells22. As discussed in further detail below, the subsea system10(e.g., the subsea tree14, the subsea station18, the manifold26, and/or the pump station34) may include one or more geothermal power systems36(e.g., subsea geothermal power systems) that provide primary and/or secondary power over one or more buses to various subsea stations (e.g., actuators, sensors, etc.). For example, the one or more geothermal power systems36may be configured to provide secondary power, such as during a power loss from the primary power from the electrical cables12, to operate various valves, sensors, and other subsea stations. While the subsea system10described above is for extracting hydrocarbons, it should be understood that the present disclosure may also apply to other types of subsea systems10such as subsea injection systems (e.g., subsea gas injection system, subsea water injection system, and/or subsea carbon dioxide injection system).

FIG.2is a schematic view of the subsea system10ofFIG.1having one or more geothermal power systems36(e.g., geothermal power systems50,52,54,56,58,60,62, and64) coupled to various subsea equipment38of the subsea system10. In the illustrated embodiment, the subsea system10includes a plurality of wells22(e.g., wells66,68,70, and72) fluidly coupled to the manifold26. The manifold26is fluidly coupled to the pump station34, which pumps the production fluid produced by the wells22to the surface platform. As shown, the subsea system10also includes a power station74that may receive power from the surface platform and/or one or more of the geothermal power systems36. Additionally or alternatively, the power station74may distribute power to the pump station34, the manifold26, hardware associated with the wells22, and/or one or more of the geothermal power systems36.

The subsea system10also includes a controller76. The controller76includes a memory78, a processor80, instructions82stored on the memory78and executed by the processor80, and communication circuitry84. The subsea system10also includes one or more sensors86(e.g., sensors88,90) coupled to hardware (e.g., trees, valves, blow-out preventers (BOPs), etc.) associated with the wells22and/or the geothermal power systems36, and communicatively coupled to the controller76. The sensors88,90may include temperature sensors, pressure sensors, flow rate sensors, water content sensors, electrical load sensors, or a combination thereof. In certain embodiments, the sensors86may include additional sensors coupled to the manifold26, the pump station34, and/or the power station74. In certain embodiments, the controller76may be communicatively coupled to the one or more geothermal power systems36, the manifold26, the pump station34, and/or hardware associated with the one or more wells22.

While the illustrated embodiment shows four wells22and eight geothermal power systems36, it should be recognized that the subsea system10may include more or fewer wells22and/or geothermal power systems36. For example, the subsea system10may include 1, 2, 3, 5, 6, 7, 8, 9, 10, or more wells22and/or 1, 2, 3, 4, 5, 6, 7, 9, 10, or more geothermal power systems36. Additionally or alternatively, while the illustrated embodiment shows one manifold26, one power station74, and one controller76, the subsea system10may include one or more manifolds26, one or more power stations74, and/or one or more controllers76.

In the illustrated embodiment, the geothermal power systems36are shown as being distributed at different locations throughout the subsea system10. As shown, one or more of the geothermal power systems36(e.g., geothermal power systems50,52,54,56,58) may be coupled to a subsea station92fluidly coupled to one or more of the flow lines28. For example, the geothermal power systems50,52, and54are coupled to subsea stations92(e.g., trees, blow-out preventers, etc.) that are coupled to the wells22. Additionally or alternatively, the geothermal power systems36may be coupled to subsea station92located away from the wells22. For example, the geothermal power systems56and58are coupled to the manifold26and the pump station34, respectively. Additionally or alternatively, the geothermal power systems36may be coupled to the flow lines28(e.g., fluid conduits or pipes) as standalone systems. For example, the geothermal power systems60,62, and64are shown as being fluidly coupled to the flow lines28as standalone units.

In certain embodiments, the geothermal power systems36may be configured to retrievably couple to the manifold26, subsea station92associated with the wells22, and/or the flow lines28. That is, the geothermal power system36may be a retrievable module that may be configured to be retrieved by a remotely operated vehicle (ROV) or another device. In other embodiments, the geothermal power systems36may be pre-installed in the subsea station92prior to installation of the hardware. Additionally or alternatively, the geothermal power systems36may include standalone non-retrievable structures. It should be recognized that the geothermal power systems36may include any combination of configurations described herein (e.g., retrievable, standalone, pre-installed, etc.).

The one or more of the geothermal power systems36may include a geothermal power plant configured to receive thermal energy from the flow lines28. In certain embodiments, the geothermal power systems36may include a separator (e.g., seeFIG.6) fluidly coupled to the flow lines28and configured to separate the production flow in the flow lines28into water and production fluid. In certain embodiments, the geothermal power systems36may include dedicated geothermal wells drilled into the seabed20and a geothermal power plant fluidly coupled to the dedicated geothermal wells. In certain embodiments, the geothermal power systems36may include a combination of the configurations described herein (e.g., geothermal power plant, geothermal power plant and separator, geothermal wells and geothermal power plant). The geothermal power systems36are described in greater detail herein.

FIG.3is a schematic view of the geothermal power system36ofFIG.2having a geothermal power plant108and a plurality of geothermal wells110with an enhanced geothermal system (EGS) configuration, wherein the geothermal power plant108is coupled to and powers at least one subsea equipment38. In certain embodiments, the geothermal power plant108and the subsea equipment38may be directly coupled or mounted together, the geothermal power plant108and the subsea equipment38may be mounted in close proximity to one another (e.g., within equal to or less than 1, 2, 3, 4, or 5 meters from one another), the geothermal power plant108and the subsea equipment38may be mounted in a vertical stack one over another, and/or the geothermal power plant108and the subsea equipment38may be mounted in horizontal side-by-side arrangement. Additionally, the geothermal power plant108and the subsea equipment38may be mounted in situ at a particular subsea station92, the well22, or other subsea equipment of the subsea system10. In the illustrated embodiment, the geothermal power plant108and the subsea equipment38may be mounted in situ with the plurality of geothermal wells110in a subsea environment, such as along the sea floor20. The subsea equipment38may include any mechanically driven and/or electrical driven equipment in the subsea system10, as discussed below. In specific embodiments, the subsea equipment38includes one or more of a pump or pump station, a compressor or compressor station, a separation or separation station, a valve or arrangement of valves, a controller or control system, a sensor or monitoring system coupled to multiple sensors, an energy storage system (e.g., batteries, supercapacitors, etc.), or any combination thereof. In certain embodiments, the energy storage system is part of the geothermal power system36.

In the illustrated embodiment, the geothermal power plant108is fluidly coupled to a plurality of geothermal well connections109, which are configured to couple to the plurality of geothermal wells110. As shown, the plurality of geothermal wells110include a producer well112(e.g., extraction well) and an injector well114. The producer well112is configured to provide the geothermal power plant108with a flow of water116(or other thermal fluid) having thermal energy. Although water may be used as the thermal fluid, the geothermal power plant108may include any suitable liquid or gas as the thermal fluid (e.g., production fluid, gas, oil, chemicals, etc.). The geothermal power plant108is configured to receive thermal energy from the water116flowing from the producer well112and convert the received thermal energy into electrical and/or mechanical energy. The geothermal power plant108injects thermal energy-depleted water116into the injector well114, which is configured to receive thermal energy-depleted water from the geothermal power plant108. Although the illustrated embodiment shows the plurality of geothermal wells110having a pair of geothermal wells118having one producer well112and one injector well114, the plurality of geothermal wells110may include any number of pairs of geothermal wells118. For example, the plurality of geothermal wells110may include 2, 3, 4, 5, 6, 7, 8, 9, 10 or more pairs of geothermal wells118, where each pair of geothermal wells118has a producer well112and an injector well114.

In the illustrated embodiment, the producer well112and the injector well114intersect a plurality of fractures120disposed beneath the seabed20. The plurality of fractures120may be formed by conventional fracking methods. The plurality of fractures120increase a permeability of a rock formation122in the vicinity of a natural reservoir124of geofluid (e.g., water, hydrocarbons, etc.). The increase in permeability causes the formation of an artificial geothermal reservoir126from which the water116may be extracted. In certain embodiments, the producer well112and the injector well114are offset by a distance (e.g., a geological formation gap128), thereby forming an open loop. The offset or gap128between the producer well112and the injector well114helps to maintain a temperature differential in the water116being extracted from the artificial geothermal reservoir126and the water being injected into the artificial geothermal reservoir126. In the illustrated embodiment, each producer well112includes a generally vertical well portion112A and a generally horizontal well portion112B (e.g., lateral well portion), and each injector well114includes a generally vertical well portion114A and a generally horizontal well portion114B (e.g., lateral well portion). The offset or gap128may be generally between the horizontal well portions112B and114B.

In certain embodiments, the geothermal power plant108may include a pump130configured to pump the water116from the producer well112, through the geothermal power plant108, and into the injector well114. In certain embodiments, the pump130may include a downhole pump (e.g., electrical submersible pump) positioned at the bottom of the producer well112. In certain embodiments, the pump130may be coupled to the geothermal well connections109or located between the geothermal well connections109and the geothermal power plant108. At the offset or gap128, the water116flows through the geological formation from the injector well114to the producer well112, wherein geothermal heat is transferred to the water116. Thus, the water116flowing through the producer well112is generally hot, whereas the water116flowing through the injector well114is generally cold. The temperatures of the hot and cold water116, and the temperature difference, may depend on the depth of the producer and injector wells112and114and other considerations. In some embodiments, the water116extracted from the producer well112may already have sufficient pressure to flow through the geothermal power plant108, such that the pump130may be omitted.

In certain embodiments, the geothermal power plant108may convert the thermal energy received from the water116to electrical energy. In certain embodiments, the geothermal power plant108may be configured to power one or more systems or subsea equipment38of the subsea system10. For example, the geothermal power system36may be configured to power the subsea equipment38, including but not limited to the pump130, a subsea pump, a subsea compressor, the pump station of the subsea system10, a separator, a tree14, valve actuators coupled to valves, BOP actuators coupled to BOPs, field extensions, the controller of the subsea system10, the manifold26, sensors and monitoring systems, communication systems, heaters (e.g., pipe heaters) or a combination thereof. In certain embodiments, the geothermal power system36may be configured to send power to the electrical cables (e.g., umbilical cables) to transfer power to the surface platform. In certain embodiments, the geothermal power plant108may convert the thermal energy received from the water116into mechanical energy. The mechanical energy may be used to power one or more machines located within the vicinity of the geothermal power plant108, such as the pump130, a compressor, a separator, and in certain embodiments, the pump station34.

FIG.4is a schematic view of the geothermal power system36ofFIG.2having a geothermal power plant108and a plurality of geothermal wells110with an advanced geothermal system (AGS) configuration, wherein the geothermal power plant108is coupled to and powers at least one subsea equipment38. In certain embodiments, the geothermal power plant108and the subsea equipment38may be directly coupled or mounted together, the geothermal power plant108and the subsea equipment38may be mounted in close proximity to one another (e.g., within equal to or less than 1, 2, 3, 4, or 5 meters from one another), the geothermal power plant108and the subsea equipment38may be mounted in a vertical stack one over another, and/or the geothermal power plant108and the subsea equipment38may be mounted in horizontal side-by-side arrangement. Additionally, the geothermal power plant108and the subsea equipment38may be mounted in situ at a particular subsea station92, the well22, or other subsea equipment of the subsea system10. In the illustrated embodiment, the geothermal power plant108and the subsea equipment38may be mounted in situ with the plurality of geothermal wells110in a subsea environment, such as along the sea floor20. The subsea equipment38may include any mechanically driven and/or electrical driven equipment in the subsea system10, as discussed below. In specific embodiments, the subsea equipment38includes one or more of a pump or pump station, a compressor or compressor station, a separation or separation station, a valve or arrangement of valves, a controller or control system, a sensor or monitoring system coupled to multiple sensors, an energy storage system (e.g., batteries, supercapacitors, etc.), or any combination thereof. In certain embodiments, the energy storage system is part of the geothermal power system36.

In the illustrated embodiment, the geothermal power plant108is fluidly coupled to a plurality of geothermal well connections109, which are configured to couple to the plurality of geothermal wells110. As shown, the plurality of geothermal wells110include a producer well112and an injector well114. The producer well112is configured to provide the geothermal power plant108with a flow of water116(or other thermal fluid) having thermal energy. Although water may be used as the thermal fluid, the geothermal power plant108may include any suitable liquid or gas as the thermal fluid. As discussed herein, the geothermal power plant108is configured to receive thermal energy from the water116flowing from the producer well112and convert the received thermal energy into electrical and/or mechanical energy. The geothermal power plant108injects thermal energy-depleted water116into the injector well114, which is configured to receive thermal energy-depleted water from the geothermal power plant108. Although the illustrated embodiment shows the plurality of geothermal wells110having a pair of geothermal wells118having one producer well112and one injector well114, the plurality of geothermal wells110may include any number of pairs of geothermal wells118. For example, the plurality of geothermal wells110may include 2, 3, 4, 5, 6, 7, 8, 9, 10 or more pairs of geothermal wells118, where each pair of geothermal wells118has a producer well112and an injector well114.

In the illustrated embodiment, the producer well112and the injector well114are coupled to each other, thereby forming a main geothermal well150that is closed loop. In the illustrated embodiment, the geothermal power system36also includes branch geothermal wells152(e.g., branch geothermal wells154,156) that branch off of the main geothermal well150. The branch geothermal wells152are also closed loop, that is, they form a closed loop with the main geothermal well150. Although the illustrated embodiment shows two branch geothermal wells152, the geothermal power system36may include 1, 3, 4, 5, 6, 7, 8, 9, or more branch geothermal wells152. The water116within the main geothermal well150and the plurality of branch geothermal wells152may absorb heat from the surrounding geological formation158. Thus, the plurality of geothermal wells110having the AGS configuration may function similarly to a heat exchanger. In certain embodiments, the geothermal power system36may include a combination of one or more pairs of geothermal wells118having the EGS configuration and one or more pairs of geothermal wells118having the AGS configuration.

In certain embodiments, the geothermal power plant108may include a pump130configured to pump the water116from the producer well112, through the geothermal power plant108, and into the injector well114. At the main geothermal well150and the branch geothermal wells152, the geological formation158transfers geothermal heat to the water116. Thus, the water116flowing through the producer well112is generally hot, whereas the water116flowing through the injector well114is generally cold. The temperatures of the hot and cold water116, and the temperature difference, may depend on the depth of the producer and injector wells112and114and other considerations. In some embodiments, the water116extracted from the producer well112may already have sufficient pressure to flow through the geothermal power plant108, such that the pump130may be omitted.

In certain embodiments, the geothermal power plant108may convert the thermal energy received from the water116to electrical energy. In certain embodiments, the geothermal power plant108may be configured to power one or more systems or subsea equipment38of the subsea system10. For example, the geothermal power system36may be configured to power the subsea equipment38, including but not limited to the pump130, a subsea pump, a subsea compressor, the pump station of the subsea system10, a separator, a tree14, valve actuators coupled to valves, BOP actuators coupled to BOPs, field extensions, the controller of the subsea system10, the manifold26, sensors and monitoring systems, communication systems, heaters (e.g., pipe heaters), or a combination thereof. In certain embodiments, the geothermal power system36may be configured to send power to the electrical cables (e.g., umbilical cables) to transfer power to the surface platform. In certain embodiments, the geothermal power plant108may convert the thermal energy received from the water116into mechanical energy. The mechanical energy may be used to power one or more machines located within the vicinity of the geothermal power plant108, such as the pump130, a compressor, a separator, and in certain embodiments, the pump station34.

In certain embodiments, one or more geothermal power plants108may fluidly couple to one or more dedicated geothermal manifolds configured to redirect and/or merge one or more geofluid lines. In certain embodiments, the geothermal manifolds may be located proximate to or coupled to one or more manifolds used for production fluid. That is, in certain embodiments a unified manifold may be used for both production fluid and geofluid used by the one or more geothermal power plants108.

FIG.5is a schematic view of the geothermal power system36ofFIG.2retrievably coupled to a portion180(e.g., receptacle) of the subsea station92along a fluid flow path170through the subsea station92, wherein the fluid flow path170couples to a flow line28. In the illustrated embodiment, the geothermal power system36includes the geothermal power plant108, which may include a plurality of components172configured to convert energy (e.g., thermal energy) of the fluid flow into power (e.g., electrical power and/or mechanical power). For example, as discussed in detail below with reference toFIG.5, the components172may include a fluid flow circuit (e.g., fluid flow loop), heat exchangers along the fluid flow circuit, a turbine driven by fluid flow along the fluid flow circuit, and an electrical generator driven by the turbine. In certain embodiments, the geothermal power system36is configured to generate power (e.g., electrical power and/or mechanical power) to operate various components coupled to and/or integrated within the subsea station92, such as components174coupled to the subsea tree14and/or components176coupled to the wellhead16. In certain embodiments, the components172,174, and/or176may include a separator configured to separate liquids, gases, and/or solids from one another. The separator may include a cyclone or centrifugal separator, a gravity separator, a filter separator, a scrubber, a vertical pressure vessel separator, a horizontal pressure vessel separator, a two-phase separator, a three-phase separator, or any combination thereof. For example, the separator may separate different liquids from one another, different gases from one another, gases from liquids, gases from solids, liquids from solids, or any combination thereof. In certain embodiments, the separator may separate water from production fluid (e.g., oil). An example configuration with a separator210is discussed in detail below with reference toFIG.6. The separator210may be coupled to the geothermal power system36or, in certain embodiments, another structure separate from the geothermal power system36. In certain embodiments, the components172,174, and/or176may include a controller (e.g., a controller having a processor, memory, communication circuitry, etc.) configured to control equipment at the subsea station92, sensors (e.g., pressure, temperature, fluid composition, water content, etc.), compressors, pumps, valves (e.g., valves actuated by electric actuators), chemical injection metering valve (CIMV) modules for controlling the injection of chemicals, downhole tools, safety/emergency systems, or any combination thereof, coupled to and powered by the geothermal power system36.

As shown, the geothermal power system36may have a retrievable housing178(e.g., retrievable process module or RPM) that is retrievably coupled to the subsea station92(e.g., the subsea tree14) at the portion180, wherein the retrievable housing178and the portion180may include a plurality of releasable connections183. The releasable connections183may include one or more of a mechanical connector, a fluid connector, an electrical connector, or any combination thereof. For example, the mechanical connector may include mating mechanical connectors, such as a hook and slot connector, clamps, threaded fasteners, rotating connectors, or any combination thereof. By further example, the electrical connectors may include one or more mating electrical connectors, such as male and female electrical connectors, which may connect and release via an axial push or pull, a rotational twist, a threaded connection, a hinged connection, or any combination thereof. By further example, the fluid connectors may include mating fluid connectors, such as male and female fluid connectors, which may connect and release via an axial push or pull, a rotational twist, a threaded connection, a hinged connection, or any combination thereof. In certain embodiments, the geothermal power system36also may include ROV connectors185, such that an ROV can connect to the ROV connectors185for installation or removal of the geothermal power system36. In certain embodiments, the ROV connectors185may include actuators to engage or release the various releasable connections183. For example, the ROV may be configured to push, pull, rotate, or otherwise move at least one of the ROV connectors185to engage or release the various releasable connections183.

In the illustrated embodiment, the subsea station92includes the subsea tree14coupled to the well22via the wellhead16. In certain embodiments, the subsea station92may be located away from the well22. For example, the subsea station92may include the manifold26, the pump station34, or a combination thereof. In certain embodiments, the manifold26may include a production fluid manifold configured to merge and/or redirect production fluid. Additionally or alternatively, as discussed herein, the manifold26may include a geothermal fluid manifold configured to merge and/or redirect geofluid (e.g., water) used for geothermal power generation. Although the illustrated embodiment shows the geothermal power system36being retrievable from the subsea station92, in certain embodiments the geothermal power system36may be pre-installed on the subsea station92as discussed herein.

In the illustrated embodiment, the geothermal power system36is configured to receive thermal energy182from the production fluid (e.g., hydrocarbon fluid, such as oil, gas, etc.) flowing through the fluid flow path170. In certain embodiments, the geothermal power system36may receive thermal energy from a flow of geofluid (e.g., geothermally heated water or other thermal fluid) in a geofluid line separated from the fluid flow path170. The geothermal power system36is also configured to convert the thermal energy182received from the production fluid into electrical energy184and/or mechanical energy186via the geothermal power plant108. In certain embodiments, the geothermal power system36is coupled to the subsea station92of any type of well22, including but not limited to hydrocarbon production wells (e.g., oil and/or gas wells), geothermal wells, carbon capture and storage (CCS) wells, any combination thereof. However, regardless of the type of well22, the geothermal power plant108receives thermal energy from the fluid flow in and/or out of the wells22.

In the illustrated embodiment, the geothermal power system36is configured to distribute the electrical energy184and/or the mechanical energy186to one or more power consumers188of the subsea system10and/or the components174and176. For example, the geothermal power system36may be configure to transmit electrical energy184to the manifold26, the pump station34, the controller76, the separator210, the tree14, the field extensions, and/or the electrical cables12(e.g., umbilical cables). Additionally or alternatively, the geothermal power system36may be configured to transfer mechanical energy186to one or more power consumers188having moving parts, such as the separator210, compressors, pumps, and/or the pump station34.

In certain embodiments, the geothermal power system36may be configured to clamp onto an exterior portion of an already-existing flow line28. In certain embodiments, the geothermal power system36may be configured to couple to one or more valves of the subsea station92. The subsea station92may be configured to internally re-route the production flow to flow into the geothermal power system36via a first valve190and out of the geothermal power system36via a second valve192. Thus, the geothermal power system36may be fluidly coupled to the fluid flow path170or fluidly separate (i.e., isolated) from the fluid flow path170. In either case, the geothermal power system36is thermally coupled to the fluid flow path170, thereby enabling heat transfer of the thermal energy182to generate power as the electrical energy184and/or the mechanical energy186.

FIG.6is a schematic view of the geothermal power system36ofFIG.2configured to power a separator210. As shown, the geothermal power system36includes the separator210(e.g., subsea separator) coupled to the fluid flow path170and/or the flow line28carrying the production flow. In certain embodiments, the geothermal power plant108may be directly coupled or mounted to the separator210, the geothermal power plant108may be mounted in close proximity to the separator210(e.g., within equal to or less than 1, 2, 3, 4, or 5 meters from the separator210, the geothermal power plant108and the separator210may be mounted in a vertical stack one over another, and/or the geothermal power plant108and the separator210may be mounted in horizontal side-by-side arrangement. Additionally, the geothermal power plant108and the separator210may be mounted in situ at a particular subsea station92, well22, or other subsea equipment of the subsea system10.

In certain embodiments, the separator210includes a cyclone or centrifugal separator, a gravity separator, a filter separator, a scrubber, a vertical pressure vessel separator, a horizontal pressure vessel separator, a two-phase separator, a three-phase separator, or any combination thereof. The separator210may separate different liquids from one another, different gases from one another, gases from liquids, gases from solids, liquids from solids, or any combination thereof. In certain embodiments, the separator may separate water from production fluid (e.g., oil). For example, the separator210may be configured to separate a raw production fluid flow209into a treated production fluid flow211(e.g., hydrocarbons) in a production flow line212and a separated fluid flow215(e.g., water116) in a separated flow line214(e.g., water flow line) that branches off from the flow line28at a junction213. As shown, the geothermal power system36also includes the geothermal power plant108coupled to a portion216of the separated flow line214. The geothermal power plant108is configured to receive thermal energy182from the separated fluid flow215(e.g., water116) in the separated flow line214. The geothermal power plant108is also configured to power the separator210using the thermal energy182received from the separated flow line214.

In certain embodiments, the geothermal power plant108is configured to convert the received thermal energy182into the electrical energy184via an evaporator240(e.g., heat exchanger), a condenser248(e.g., heat exchanger), a turbine244, and a generator242of the geothermal power plant108(e.g., seeFIG.7). The geothermal power plant108may be configured to power the separator210using the electrical energy184. For example, the geothermal power plant108may transmit the electrical energy184to the separator210via one or more electrical wires (e.g., energy transmission218). In other embodiments, the geothermal power plant108may generate mechanical energy186via the turbine244and may transmit the mechanical energy186to the separator210via a shaft and/or one or more gears (e.g., energy transmission218) coupling the turbine244with the separator210. In certain embodiments, the geothermal power plant108may transmit a combination of the electrical energy184and the mechanical energy186to the separator210.

Although the illustrated embodiment shows the separator210as being proximate to the geothermal power plant108, in certain embodiments the separator210may be located away (e.g., disjoint) from the geothermal power plant108. For example, the geothermal power plant108and the separator210may be disposed in a single packaged and/or retrievable unit. Additionally or alternatively, the packaged and/or retrievable unit may include the geothermal power plant, the separator, an energy storage system, one or more sensors, a controller, or any combination thereof. It should be recognized that any component (e.g., the separator, the geothermal power plant, etc.) disposed within the packaged and/or retrievable unit may be appropriately sized to fit within the packaged and/or retrievable unit. In certain embodiments, the geothermal power plant108and the separator210may be disposed in separate units. Additionally, although the illustrated embodiment shows the separator210contacting the seabed20, in certain embodiments the separator210may not contact the seabed20.

In certain embodiments, the geothermal power system36(e.g., having the geothermal power plant108and the separator210) may be coupled to a subsea hardware or equipment fluidly coupled to one or more of the flow lines28. For example, the subsea hardware may include a tree, a production manifold configured to redirect (e.g., merge) one or more flow lines28of production fluid, and/or a geothermal manifold configured to redirect one or more geothermal flow lines (e.g., flow lines214). In certain embodiments, the geothermal power system36may be coupled to subsea hardware or equipment located away from the wells22. Additionally or alternatively, the geothermal power system36may be coupled to the flow line28as a standalone system.

In certain embodiments, the geothermal power system36may be configured to retrievably couple to the manifold, subsea hardware associated with the wells22, and/or the flow lines28. That is, the geothermal power system36may be a retrievable module (e.g., retrievable housing178) that may be configured to be retrieved by the ROV or another device. In certain embodiments, the geothermal power system36may be pre-installed in the subsea hardware prior to installation of the hardware. In certain embodiments, a portion or subsystem of the geothermal power system36may be retrievable while a main body of the geothermal power system36remains in place. For example, the geothermal power plant108, the separator210, or a combination thereof, may be retrievable from a subsea structure. Additionally or alternatively, the geothermal power system36may include standalone non-retrievable structures. It should be recognized that the geothermal power system36may include any combination of configurations described herein (e.g., retrievable, standalone, pre-installed, etc.).

Although the illustrated embodiment shows the geothermal power system36having a single geothermal power plant108and a single separator210, the geothermal power system36may have one or more geothermal power plants108and/or one or more separators210. For example, the geothermal power system36may include multiple separators210as part of a multi-step separation (e.g., filtering) process of the production flow. Additionally or alternatively, the geothermal power system36may include one or more geothermal power plants108in order to maximize an amount of thermal energy182received from the separated geofluid line.

The subsea system10may include any combination of the types of geothermal power systems36discussed herein. That is, the subsea system10may include one or more geothermal power systems36that retrievably couple to a subsea module (e.g., retrievable process modules), one or more geothermal power systems36that include dedicated geothermal wells22fluidly coupled to a geothermal power plant108, one or more geothermal power systems36that include a geothermal power plant108packaged with a separator210, or any combination thereof.

FIG.7is a schematic view of a high-level architecture of the geothermal power system36ofFIGS.1-6. In the illustrated embodiment, the geothermal power system36includes the producer well112, the injector well114, and the geothermal power plant108. The geothermal power plant108also includes a plurality of subsystems238, including an evaporator240(e.g., heat exchanger or heater) fluidly coupled to the producer well112and the injector well114. The subsystems238of the geothermal power plant108also include a generator242coupled to and driven by a turbine244, which is fluidly coupled to the evaporator240. As illustrated, the geothermal power plant108has the evaporator240, the turbine244, the condenser248, and a pump254arranged in a fluid circuit237. The turbine244includes a shaft246that is coupled to the generator242. The subsystems238also include the condenser248that is fluidly coupled to the turbine244. The condenser248is configured to receive and output a coolant250. The subsystems238also include the pump254fluidly coupled to the condenser248. As shown, the pump254is disposed between the condenser248and the evaporator240.

As shown, the producer well112produces hot geofluid256(e.g., mostly water, some hydrocarbons, dissolved minerals, etc.), which is received by the geothermal power plant108of the geothermal power system36. The hot geofluid256is received by the evaporator240, which is configured to receive the thermal energy182from the hot geofluid256and use the thermal energy182to heat a fluid257(e.g., thermal fluid) flowing through the evaporator240and the entire fluid circuit237. The fluid257may include any suitable working fluid, such as water and/or steam. The evaporator240is configured to heat the fluid257to produce a heated water and/or steam258. The evaporator240outputs cold geofluid259for return back into the injector well114.

The heated water and/or steam258is received by the turbine244and used to drive (e.g., rotate or spin) the turbine244, the shaft246, and the generator242, thereby generating electricity. The electricity generated by the generator242may be sent to one or more subsea stations92of the subsea system10(e.g., the controller, the manifold, the pump station, the tree, etc.). The heated water and/or steam258exits the turbine244and enters the condenser248, which cools the heated water and/or steam258to produce a cooled fluid257(e.g., water or condensate) via heat transfer with the coolant250flowing through the condenser248. The cooled fluid257is pumped back to the evaporator240via the pump254, where the cycle is repeated to recover heat from the hot geofluid256to generate electricity.

In certain embodiments, the pump254of the geothermal power plant108may be powered by electricity generated by the generator242and/or mechanically powered via the shaft246of the turbine244. As discussed herein, the geothermal power plant108may be configured to export electricity generated by the generator242and/or mechanical energy transferred by the shaft246to one or more subsea stations92of the subsea system10.

Although the illustrated embodiment shows the geothermal power plant108having one of each of the subsystems238(e.g., the evaporator240, the generator242, the turbine244, the condenser248, the pump254, the geothermal power plant108may include one or more of each of the subsystems238. For example, the geothermal power plant108may include 2, 3, 4, 5, 6, 7, 8, 9, or any suitable number of each of the subsystems238. Additionally, although the illustrated embodiment shows the geothermal power system36having a pair of geothermal wells118having one producer well112and one injector well114, in certain embodiments the geothermal power system36may include 2, 3, 4, 5, 6, 7, 8, 9, or any suitable number of pairs of geothermal wells118.

FIG.8is a flowchart of an example process280for operating the geothermal power system ofFIG.2. The process280may be performed by a processor-based computing device or controller disclosed above with reference toFIG.2or any other suitable computing device(s) or controller(s). Furthermore, the blocks of the process280may be performed in the order disclosed herein or in any other suitable order. For example, certain blocks of the process280may be performed concurrently. In addition, in certain embodiments, at least one of the blocks of the process280may be omitted.

In block282of the process280, a processor of a controller receives a signal from a sensor disposed in the subsea system10indicative of a water content (e.g., per volume content) of the production flow from a well (e.g., production well, hydrocarbon well). In certain embodiments, the sensor may direct a waveform signal (e.g., microwave) at a portion of the production flow to determine one or more characteristics of the fluid (e.g., permittivity, conductivity). In block284of the process280, the processor determines an estimated water content of the production flow based on the signal received from the sensor.

In block288of the process280, in response to the estimated water content of the production flow exceeding a threshold water content (block286), the processor controls (e.g., instructs) a geothermal power system36of the subsea system10to receive thermal energy from the production flow flowing through a flowline. That is, the geothermal power system36is activated (e.g., initiated) to begin receiving thermal energy in response to the estimated water content of the production flow exceeding a threshold water content value. For example, the threshold water content may be more than 10, 20, 30, 40, 50, 60, 70, 80, or 90 percent of the production flow being water.

In block290of the process280, in response to the estimated water content of the production flow exceeding the threshold water content, the processor controls the geothermal power system36to convert the received thermal energy into electrical energy and/or mechanical energy. In certain embodiments, the processor controls a separator of the geothermal power system to separate water into a separate water line from the production flow. The processor may control the geothermal power system36to receive thermal energy from the separated water, thereby converting the received thermal energy into electrical energy and/or mechanical energy.

In certain embodiments, the processor may control the geothermal power system36to send the electrical energy to one or more subsea stations92and/or subsea equipment38(e.g., subsea hardware, power consumers). In certain embodiments, the one or more subsea stations92and/or subsea equipment38may include a tree, a manifold, a pump station configured to pump the production flow to a surface platform, a controller, a field extension, an electrical cable (e.g., umbilical cable) configured to send electrical energy to a surface platform, or a combination thereof.

In certain embodiments, the processor may be configured to monitor an operational status and/or operational parameters of the one or more power consumers (e.g., subsea stations92and/or subsea equipment38). The processor may estimate an amount of power to be consumed by the one or more power consumers based on the monitored one or more operational parameters. In certain embodiments, the processor may control a distribution of the electrical energy and/or the mechanical energy from the geothermal power system36to the one or more power consumers based on the one or more operational parameters and/or the estimated power to be consumed.

FIG.9is a flowchart of an example process310for operating the geothermal power plant108of the geothermal power system36ofFIG.2. The process310may be performed by a processor-based computing device or controller disclosed above with reference toFIG.2or any other suitable computing device(s) or controller(s). Furthermore, the blocks of the process310may be performed in the order disclosed herein or in any other suitable order. For example, certain blocks of the process310may be performed concurrently. In addition, in certain embodiments, at least one of the blocks of the process310may be omitted.

In block312of the process310, the processor of the controller may control a geothermal power plant108of the geothermal power system36to receive thermal energy from geofluid (e.g., water) extracted from one or more of the producer wells of the geothermal power system36. For example, the processor may control one or more actuators that allow the geofluid to flow into the geothermal power plant108, thereby allowing the thermal energy of the geofluid to be transferred to a fluid cycling through the geothermal power plant108.

In block314of the process310, the processor controls the geothermal power plant108to convert the received thermal energy into electrical energy. For example, the processor may send instructions to a turbine of the geothermal power plant108to receive the heated fluid (e.g., steam) from the evaporator. Additionally or alternatively, the processor may send instructions to a generator and/or the turbine to distribute the generated power between generating electrical energy via the turbine and generating mechanical energy via a shaft of the turbine. In block316of the process310, the processor controls the geothermal power plant108to transmit the electrical energy and/or the mechanical energy to a pumping station of the subsea system10.

In block318of the process310, the processor controls the geothermal power plant108to inject the geofluid (e.g., thermal energy-depleted water) into one or more injection wells (e.g., injector wells) of the geothermal power system36. For example, the processor may control a pump configured to pump the geofluid out of the producer well, through the geothermal power plant108, and into the injector well. In certain embodiments, the injector well may be offset from the producer well (e.g., EGS configuration). In other embodiments, the injector well may form a closed loop with the producer well (e.g., AGS configuration). In certain embodiments, the geothermal power system36may include wells that have the EGS configuration, the AGS configuration, or a combination thereof.

In certain embodiments, the processor receives a signal from a sensor disposed in the subsea system10indicative of a temperature of the geofluid (e.g., water) flowing from one or more of the geothermal producer wells (e.g., extraction wells). The processor may be configured to determine an estimated temperature of the water flowing from the one or more geothermal producer wells based on the signal. In certain embodiments, the processor may actuate an actuator assembly to adjust a flow rate of the water flowing from the one or more producer wells in response to the estimated temperature falling below a threshold temperature. For example, the processor may be configured to actuate the actuator assembly to further open a valve to increase the flow rate of the geofluid in response to the estimated temperature falling below the threshold temperature. By increasing the flow rate of the geofluid, the rate at which thermal energy is drawn from the geofluid by the geothermal power plant108may be maintained (e.g., kept near constant). Furthermore, in certain embodiments, the process310may vary (e.g., increase or decrease) the flow rate of the geofluid to vary (e.g., increase or decrease) the heat transfer to the geothermal power plant108, thereby varying (e.g., increasing or decreasing) the power production for use by the various subsea stations92and/or subsea equipment38.

FIG.10is a flowchart of an example process340for operating the geothermal power system ofFIG.2. The process340may be performed by a processor-based computing device or controller disclosed above with reference toFIG.2or any other suitable computing device(s) or controller(s). Furthermore, the blocks of the process340may be performed in the order disclosed herein or in any other suitable order. For example, certain blocks of the process340may be performed concurrently. In addition, in certain embodiments, at least one of the blocks of the process340may be omitted.

In block342of the process340, a processor of the controller is configured to control a separator of the geothermal power system36to separate a production flow in a flow line (e.g., main flow line) into a production fluid flow (e.g., hydrocarbon flow) in a production flow line and a geofluid flow (e.g., water flow) in a geofluid flow line. In certain embodiments, the separator is located at a junction of the flow line, the production flow line, and the geofluid flow line. In certain embodiments, the geofluid flow line branches off from the flow line, and the production flow line is axially aligned with the flow. In block344of the process340, the processor controls the geothermal power plant108to receive thermal energy from the geofluid flow in the geofluid flow line. Additionally or alternatively, the processor may control the geothermal power plant108to receive thermal energy from the production fluid flow in the production flow line.

In block346of the process340, the processor controls the geothermal power plant108to convert the received thermal energy into electrical energy and/or mechanical energy. In certain embodiments, the controller may be configured to adjust a ratio between the amount of electrical energy and the amount of mechanical energy produced by the geothermal power plant108. For example, the controller may be configured to adjust one or more parameters of a generator of the geothermal power plant108and/or adjust a transmission used in conjunction with a shaft of a turbine of the geothermal power plant108.

In block348of the process340, the processor controls the geothermal power system to power the separator using the electrical energy and/or the mechanical energy generated by the geothermal power plant108. Additionally, the processor may instruct the geothermal power system36to distribute the electrical energy and/or the mechanical energy generated by the geothermal power plant108to one or more subsea stations92. In certain embodiments, extra electrical energy generated by the geothermal power plant108may be stored in one or more batteries or energy storage units for later use.

In certain embodiments, the processor may receive a signal from a sensor disposed in the subsea system10indicative of a temperature of a production flow received from a well of the subsea system10. The processor may determine an estimated temperature of the production flow based on the received signal. In response to the estimated temperature of the production flow falling below a threshold temperature, the processor may actuate an actuation assembly to open a bypass valve in a geothermal power system36of the subsea system10to cause a cessation of flow of the production flow into a geothermal power plant108of the geothermal power system36. It may be appreciated that by the processor causing the production flow to bypass the geothermal power plant108in response to the estimated temperature of the production flow falling below the threshold temperature, the formation of hydrates within the geothermal power plant108may be mitigated, thereby mitigating the risk of damage sustained by the geothermal power plant108.

In certain embodiments, the processor may receive a signal from a sensor disposed in the geothermal power plant108indicative of an amount of power output by the geothermal power plant108. The processor may determine an estimated amount of power output by the geothermal power plant108based on the signal. In certain embodiments, the processor may control one or more batteries of the subsea system10to supply power to the separator in response to the estimated amount of power falling below a threshold amount of power. In certain embodiments, the processor may control the one or more batteries to supply power to one or more additional stations of the subsea system10in response to the estimated amount of power falling below the threshold amount of power.

FIG.11is a flowchart of an example process370for controlling the subsea system ofFIG.1. The process370may be performed by a processor-based computing device or controller disclosed above with reference toFIG.2or any other suitable computing device(s) or controller(s). Furthermore, the blocks of the process370may be performed in the order disclosed herein or in any other suitable order. For example, certain blocks of the process370may be performed concurrently. In addition, in certain embodiments, at least one of the blocks of the process370may be omitted.

In block372of the process370, the subsea system receives thermal energy from a well fluid received from a hydrocarbon well in a geothermal power plant fluidly coupled to a well connection. As discussed herein, a geothermal power system of the subsea system may include one or more well connections configured to couple to one or more geothermal wells.

In block374of the process370, the subsea system converts the thermal energy into at least one of electrical energy and mechanical energy. For example, a geothermal power plant may use the thermal energy to produce steam to turn a turbine. The turbine may produce mechanical energy and/or may be used in conjunction with a generator to produce electrical energy.

In block376of the process370, the subsea system at least partially powers a subsea equipment with at least one of the electrical energy and the mechanical energy produced by the subsea geothermal power system. For example, the subsea system may at least partially power a pump station, a manifold, a separator, a tree, a controller, or a combination thereof using at least one of the electrical energy and the mechanical energy produced by the subsea geothermal power system.

Technical effects of the disclosed embodiments include one or more geothermal power systems36that are distributed throughout a subsea system10that may be used to produce power that may be utilized by the subsea system and/or a surface platform. In particular, the disclosed embodiments may be used for powering one or more subsea equipment38, including but not limited to trees coupled to one or more wells throughout the field, one or more field extensions, the controller, the pump station, the manifold, subsea boosting, subsea compression, pipe heating, or a combination thereof. In certain embodiments, power produced by the one or more geothermal power systems36may be sent to a surface platform via an electrical cable (e.g., umbilical cable). It may be appreciated that a geothermal power system36that includes a plurality of geothermal wells may produce sufficient power to eliminate the three phase power cable portion of the electrical cables connecting the surface platform, thereby reducing the manufacturing cost of the electrical cable. A geothermal power system36having a plurality of geothermal wells may also eliminate the traditional fuel (e.g., diesel fuel) that may be used for powering pumps and/or separators. Additionally, the one or more geothermal power systems may be able to mitigate the chance of losing power due to a loss of power transmission through the electrical cable. The use of one or more geothermal power systems36disposed throughout the subsea system10also produces zero carbon emissions, thereby offsetting and potentially reducing the amount of carbon emissions produced for powering various stations of the subsea system10.

The subject matter described in detail above may be defined by one or more clauses, as set forth below.

A system includes a subsea geothermal power system. The subsea geothermal power system includes a separator configured to separate a well fluid from a hydrocarbon well into a first fluid flow and a second fluid flow. The subsea geothermal power system also includes a geothermal power plant coupled to the separator. The geothermal power plant is configured to receive thermal energy from the second fluid flow and convert the thermal energy into at least one of electrical energy and mechanical energy. The separator is at least partially powered by the at least one of electrical energy and mechanical energy produced by the subsea geothermal power system.

The system of the preceding clause, wherein the first fluid flow includes a hydrocarbon fluid flow and the second fluid flow includes water.

The system of any preceding clause, wherein the separator is at least partially powered by the mechanical energy produced by the subsea geothermal power system.

The system of any preceding clause, wherein the separator is at least partially powered by the electrical energy produced by the subsea geothermal power system.

The system of any preceding clause, wherein the geothermal power plant is directly coupled to the separator.

The system of any preceding clause, comprising a packaged unit having both the geothermal power plant and the separator.

The system of any preceding clause, wherein the packaged unit is a retrievable module configured to be retrieved by a remotely operated vehicle (ROV).

The system of any preceding clause, wherein the packaged unit includes an energy storage system configured to store the electrical energy.

The system of any preceding clause, wherein the subsea geothermal power system is configured to produce the electrical energy dedicated only to the separator.

The system of any preceding clause, further including a first retrievable module and a second retrievable module each configured to be retrieved by a remotely operated vehicle (ROV), wherein the first retrievable module comprises the geothermal power plant, and the second retrievable module comprises the separator.

The system of any preceding clause, wherein the geothermal power plant includes a fluid circuit having a first heat exchanger configured to transfer the thermal energy from the second fluid flow to a thermal fluid circulating in the fluid circuit, and a turbine driven by the thermal fluid.

The system of any preceding clause, further including an electrical generator driven by the turbine to generate the electrical energy.

The system of any preceding clause, further including a wellhead, a tree, a manifold, a pump, a compressor, a valve, a flow line, or any combination thereof, coupled to the separator.

The system of any preceding clause, wherein the geothermal power plant and the separator are arranged in a vertical stack one over another.

A system includes a subsea retrieval module. The subsea retrievable module includes a separator configured to separate a well fluid from a hydrocarbon well into a hydrocarbon flow and a water flow. The subsea retrievable module also includes a geothermal power plant coupled to the separator. The geothermal power plant includes a fluid circuit having a first heat exchanger configured to transfer thermal energy from the water flow to a thermal fluid circulating in the fluid circuit, and a turbine driven by the thermal fluid. The separator is at least partially powered by at least one of mechanical energy generated by the turbine and electrical energy generated by an electrical generator driven by the turbine of the geothermal power plant.

The system of the preceding clause, wherein the geothermal power plant further includes the electrical generator driven by the turbine to generate the electrical energy.

The system of any preceding clause, wherein the separator is entirely powered by the at least one of mechanical energy and electrical energy from the geothermal power plant.

A method includes controlling, via a processor, a separator of a geothermal power system to separate a well fluid from a hydrocarbon well into a first fluid flow and a second fluid flow. The method also includes controlling, via a processor, a geothermal power plant of the geothermal power system to receive thermal energy from the second fluid flow. The method also includes controlling, via the processor, the geothermal power plant to convert the thermal energy into at least one of electrical energy and mechanical energy. The method also includes controlling, via the processor, the geothermal power system to power the separator using the at least one of electrical energy and mechanical energy.

The method of the preceding clause, including receiving, via a processor, a signal from a sensor indicative of a temperature of the well fluid; determining, via the processor, an estimated temperature of the well fluid based on the received signal; and in response to the estimated temperature of the well fluid, actuating, via the processor, a first actuation assembly to adjust a valve in the geothermal power plant to adjust a flow of the well fluid through the geothermal power plant.

The method of any preceding clause, including receiving, via the processor, a signal from a sensor indicative of an amount of power output by the geothermal power plant; determining, via the processor, an estimated amount of power output by the geothermal power plant based on the signal; and controlling, via the processor, one or more batteries to supply power to the separator in response to the estimated amount of power falling below a threshold amount of power.

The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. Moreover, the order in which the elements of the methods described herein are illustrated and described may be re-arranged, and/or two or more elements may occur simultaneously. The embodiments were chosen and described in order to best explain the principals of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated.