Nuclear reactor integrated oil and gas production systems and methods of operation

Nuclear energy integrated hydrocarbon operation systems include a well site having a subsurface hydrocarbon well configured to produce a produced water output. The system further includes a deployable nuclear reactor system configured to produce a heat output. The system may further include a deployable desalination unit configured to produce a desalinated water output using the produced water output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor. The system may further include a deployable off-gas processing system configured to produce an industrial chemical using the off-gas output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor.

TECHNICAL FIELD

The described examples relate generally to systems, devices, and techniques for nuclear energy integrated oil and gas operations.

BACKGROUND

Oil and gas operations may include the production of certain hydrocarbons from subsurface reservoirs using wells that are drilled into the reservoir. In some cases, hydrocarbons may be produced from the subsurface reservoir using one or more enhanced recovery operations, including hydraulic fracturing. Broadly, hydraulic fracturing uses a pressurized fluid (often including a fracturing slurry composed of water, a proppant, and a chemical additive) that is injected into the subsurface reservoir—“production zone”—to increase a permeability of the reservoir, and thereby support the flow of hydrocarbons therein to the surface. Hydrocarbon well drilling, completion, production, fracturing, and/or other associated operations (collectively, “hydrocarbon operations”) often requires a substantial input of electrical power, e.g., to support the operation of pumps, compressors, drilling equipment, mixers, accumulators, and other equipment. Diesel generators can provide such power needs, but can be costly and unreliable. Hydrocarbon production operations may further generate substantial quantities of off-gas or casing gas (e.g., methane—CH4) and/or produced water (e.g., a recirculated fluid from the well casing and/or other fluid that is cut from produced hydrocarbon) that may represent potential waste streams. Conventional techniques for dealing with off-gas and produced water include flaring and waste-water well injection, respectively, among other techniques. However, flaring and waste-water injection techniques both fail to repurpose the waste stream for further commercial or industrial use, and regardless, such repurposing generally requires a substantial energy input. Conventional nuclear energy systems are known for affordable, clean, and reliable energy; however, such conventional systems may be impractical or infeasible for use in support of hydrocarbon operations. Accordingly, there is a need for systems and techniques to support the power consumption and waste stream processing needs of hydrocarbon operations, such as by leveraging nuclear energy systems.

SUMMARY

In one example, a system is disclosed. The system includes a well site having a subsurface hydrocarbon well configured to produce a produced water output. The system further includes a deployable nuclear reactor system configured to produce a heat output. The system further includes a deployable desalination unit configured to produce a desalinated water output using the produced water output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the well site includes a hydraulic fracturing system configured to introduce pressurized fluids into the subsurface hydrocarbon well. The produced water output may at least partially include a recirculated form of the pressurized fluids.

In another example, the pressurized fluid may include a fracturing fluid slurry including one or more of a water, a proppant, and a chemical additive.

In another example, the system further includes a desalinated water offtake network having a network of temporary piping configured to deliver the desalinated water output to one or more municipalities adjacent the well site.

In another example, the system further includes a produced water pond configured to receive the produced water output and hold the produced water output for processing. The deployable desalination unit may be configured to receive the produced water output form the produced water pond.

In another example, the subsurface hydrocarbon well may be configured to produce an off-gas output. In this regard, the system may further include a deployable off-gas processing system configured to produce an industrial chemical using the off-gas output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the deployable off-gas processing system may include a deployable hydrogen production unit configured to produce a hydrogen output using the off-gas output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the deployable off-gas processing system may include a deployable chemical production unit configured to produce the industrial chemical using the hydrogen output of the hydrogen production module and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the industrial chemical may include ammonia.

In another example, the deployable hydrogen production unit may include a steam methane refining processing unit. Further, the deployable chemical production unit may include a Haber-Bosch processing unit and/or a Fischer-Tropsch processing unit.

In another example, the system may further include a deployable electrical generation unit configured to produce an electrical power output using the heat output from the deployable nuclear reactor. In this regard, the well site may include one or more hydraulic fracturing systems, drilling systems, completion systems, or productions systems that are powered by the electrical power output of the deployable electrical generation unit.

In another example, a micro-grid is disclosed. The micro-grid includes a plurality of well sites clustered in a first geographic location. Each well site of the plurality of well sites may include a subsurface hydrocarbon well configured to produce a produced water output and an off-gas output. The micro-grid further includes a deployable plant deployed proximal the first geographic location. The deployable plant may further include a deployable nuclear reactor system configured to produce a heat output. The micro-grid may further include a network of pipes configured to deliver the produced water output and the off-gas output from each well site of the plurality of well sites to the deployable plant. The deployable plant may be configured to produce a desalinated water output and an industrial chemical output using the produce water output and the off-gas output, respectively, and the heat output from the nuclear reactor system and/or an electrical output derived therefrom.

In another example, the deployable plant may further include a deployable electrical generation unit configured to produce an electrical power output using the heat output from the deployable nuclear reactor. Further, the micro-grid may include a network of power lines configured to deliver the electrical power output to each well site of the plurality of well sites. The electrical power may be adapted to power at said well site one or more hydraulic fracturing systems, drilling systems, completion systems, or productions systems.

In another example, the plant may further include a deployable desalination unit. The plant may further include a deployable hydrogen production unit configured to perform steam methane refining. The plant may further include a deployable chemical production unit configured to perform a Haber-Bosch process and/or a Fischer-Tropsch process.

In another example, the micro-grid may include a second plurality of well sites clustered in a second geographic location. Each well site of the second plurality of well sites may include a subsurface hydrocarbon well configured to produce a produced water output and an off-gas output. The deployable plant may be redeployable proximal the second geographic location. The deployable plant may further be configured to produce a desalinated water output and an industrial chemical output using the produce water output and the off-gas output, respectively, of the second plurality of well sites and the heat output from the nuclear reactor system and/or an electrical output derived therefrom.

In another example, a method of treating an output of a well site using nuclear reactors is disclosed. The method includes operating a well site. The well site has a subsurface hydrocarbon well. The method further includes producing a produced water output from the hydrocarbon well. The method further includes operating a deployable plant deployed proximal to the well site. The deployable plant has a deployable nuclear reactor system and a deployable desalination unit. The method further includes producing a heat output from the deployable nuclear reactor system. The method further includes producing a desalinated water output from the desalination unit using the produced water output of the subsurface hydrocarbon well and the heat output of the nuclear reactor system and/or an electrical output derived therefrom.

In another example, the deployable plant may include a deployable electrical generation unit. Accordingly, the method may further include producing an electrical power output from the deployable electrical generation unit using the heat output from the deployable nuclear reactor system. The well site may include one or more hydraulic fracturing systems, drilling systems, completion systems, or productions systems. In this regard, the method may further include powering one or more of the hydraulic fracturing systems, drilling systems, completion systems, or productions systems using the electrical power output from the deployable electrical generation unit.

In another example, the method may further include producing an off-gas output from the subsurface hydrocarbon well. The deployable plant may further include a deployable hydrogen production unit and a deployable chemical production unit. Accordingly, the method may further include producing, by the deployable hydrogen production unit, a hydrogen output by performing a steam methane refining process using the off-gas output from the subsurface hydrocarbon well and the heat output from the deployable nuclear reactor and/or an electrical output derived therefrom. Further, the method may include producing, by the deployable chemical production unit, a chemical output by performing a Haber-Bosch processing using the hydrogen output from the deployable hydrogen production unit and the heat output from the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, operating the well site may further include performing one or more hydraulic fracturing operations that includes introducing pressurized fluids into the subsurface hydrocarbon well.

In another example, the produced water output may at least partially include a recirculated from of the pressurized fluids. The pressurized fluid may include a fracturing fluid slurry including one or more of a water, a proppant, and a chemical additive.

In another example, a system is disclosed. The system includes well site having a subsurface hydrocarbon well configured to produce an off-gas output. The system further includes a deployable nuclear reactor system configured to produce a heat output. The system further includes a deployable off-gas processing system configured to produce an industrial chemical using the off-gas output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the deployable off-gas processing system may further include a deployable hydrogen production unit configured to produce a hydrogen output using the off-gas output of the subsurface hydrocarbon well and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the deployable off-gas processing system may further include a deployable chemical production unit configured to produce the industrial chemical using the hydrogen output of the hydrogen production module and the heat output of the deployable nuclear reactor and/or an electrical output derived therefrom.

In another example, the industrial chemical includes ammonia.

In addition to the example aspects described above, further aspects and examples will become apparent by reference to the drawings and by study of the following description.

DETAILED DESCRIPTION

The description that follows includes sample systems, methods, and apparatuses that embody various elements of the present disclosure. However, it should be understood that the described disclosure may be practiced in a variety of forms in addition to those described herein.

The following disclosure relates generally to nuclear reactor integrated oil and gas production systems and methods of operation. Oil and gas production systems, or “hydrocarbon operations” may generally include any operations associated with extracting hydrocarbons (e.g., oil and gas) from a subsurface reservoir, including, without limitation, well site preparation, well drilling, completion, production, enhanced recovering operations including hydraulic fracturing and/or other associated operations. Broadly, hydrocarbon operations often require a substantial input of electrical power, including for the operation of pumps, compressors, drilling equipment, mixers, accumulators, controls and actuators, and any other associated equipment. Diesel generators can provide such power needs, but can be costly and unreliable. Hydrocarbon operations may further generate substantial quantities of off-gas or casing gas (e.g., methane—CH4) and/or produced water (e.g., a recirculated fluid from the well casing and/or other fluid that is cut from produced hydrocarbon) that may represent potential waste streams. Conventional techniques for dealing with off-gas and produced water include flaring and waste-water well injection, respectively, among other techniques. However, flaring and waste-water injection techniques both fail to repurpose the waste stream for further commercial or industrial use, and regardless, such repurposing generally requires a substantial energy input.

To mitigate these and other challenges associated with hydrocarbon operations, the systems and methods of the present disclosure integrate a nuclear reactor system into such hydrocarbon operations. For example, a nuclear reactor system may include an integral-type reactor, which is generally a deployable, modular unit that is capable of generating thermal energy from fission reactions. Such integral-type reactor may be a fully contained or standalone unit that is transportable to a first remote site (such as a hydrocarbon well site) at which the reactor may operate for a period of time, and may be subsequently redeployed to a second remote site for operation, upon conclusion of the operations at the first remote site. Integral-type or “deployable reactors” of the present disclosure may include substantially any type of nuclear reactor, including, without limitation, certain molten salt reactors, super critical water reactors, liquid sodium cooled reactors, helium or other gas cooled reactors, liquid metal cooled reactors, certain pressurized water reactors, among others.

The deployable reactors of the present disclosure may be used to provide for the thermal and electrical needs of the various hydrocarbon operations described herein. Further, the deployable reactors may be used to treat and/or repurpose one or more waste streams of the hydrocarbon operations, including treating and/or repurposing off-gas and/or produced water. For example, the deployable nuclear reactor may be used to produce ammonia (NH3) or other chemical product from the off-gas using one or more heat or electrical outputs derived from the fission reactions of the reactor. Further, the deployable nuclear reactor may be used to produce desalinated water from the produced water also using one or more heat or electrical outputs derived from the fission reactions of the reactor. In other cases, the waste streams of the hydrocarbon operations may be repurposed into different products.

To facilitate the foregoing, in one example, disclosed herein is a deployable plant including the deployable nuclear reactor. The deployable plant may be deployable to a hydrocarbon well or more generally to any region proximal a cluster of well sites. For example, the entire deployable plant may be capable of remote deployment and redeployment to any number of locations. In this regard, the deployable plant may include a plurality of trucks, tractor-trailers, and/or other moveable skids or components that are readily transportable between locations. One such tractor-trailer or moveable skid may include the deployable nuclear reactor. Other tractor-trailer or moveable skids may include one or more of a deployable desalination unit, a deployable electrical generation unit, a deployable hydrogen production unit, a deployable chemical production unit, and/or other deployable equipment, including certain equipment to facilitate the offtake of desalinated water, electricity, and/or chemical produced using the various deployable units.

In operation, such deployable plant may be configured to receive one or both of a produced water input or a casing gas input from certain hydrocarbon operations. In one example, the deployable plant may use the deployable desalination unit to produce desalinated water using the produced water input of the hydrocarbon operations and a heat output from the deployable nuclear reactor of the deployable plant. In another example, the deployable plant may use the deployable hydrogen production unit to produce hydrogen using the casing gas input of the hydrocarbon operations and a heat output from the deployable nuclear reactor. In another example, the deployable plant may use the deployable chemical production unit to produce a chemical output (e.g., ammonia, NH3) from the produced hydrogen of the deployable hydrogen production unit and a heat output from the deployable nuclear reactor (e.g., via a Haber-Bosch process, a Fischer-Tropsch process and/or other process). In another example, the deployable plant may use the deployable electrical generation unit to produce an electricity output from a heat output of the deployable nuclear reactor. Such electricity output may, in turn, be used to power one or more hydrocarbon operations, among other uses.

While many types of integral, or deployable-type nuclear reactors are possible and contemplated herein, in one example, the deployable nuclear reactor system includes an integral molten salt reactor (“MSR”). Broadly, an integral MSR may reduce or eliminate leaks and/or other failure mechanisms by fully enclosing the functional components (e.g., the heat exchanger, the reactor core, the pump (if used), and so on) within a common, integrally constructed vessel. For example, an integral MSRs may house a reactor core and one or more heat exchangers in a “critical region” of a common vessel, and cause a fuel salt to circulate within the common vessel between the reactor core (at which the fuel salt may undergo a fission reaction that heats the salt) and a heat exchanger (at which the heat is removed from the fuel salt). The heat that is removed from the salt may be used for or may form the various “heat outputs” of the deployable nuclear reactor described above that are provided to the deployable desalination unit, the deployable electrical generation unit, the deployable hydrogen production unit, and/or the deployable chemical production unit. In some cases, as described herein, the integral MSR may further include a subcritical region at which the fuel salt may be kept away from the reactor core and heat exchanger in a subcritical state, as may be needed to facilitate shutdown of the integral MSR. In other configurations, other components and features of the integral MSR are contemplated herein.

Turning to the Drawings,FIG.1depicts example hydrocarbon operations100for purposes of illustration. As used herein, “hydrocarbon operations” includes all types of oil and gas recovery and associated operations, including, without limitation, well site preparation, well drilling, completion, production, enhanced recovering operations including hydraulic fracturing, and/or other associated operations—any one of which, may be integrated with, and supported by, the various nuclear reactor systems described herein. In the example ofFIG.1, the example hydrocarbon operations100are shown as including an example drilling operation that utilizes a nuclear reactor system to support one or more thermal or electrical needs of the system. For example,FIG.1shows a well site102having a rig104positioned thereon. The rig104, shown schematically, includes a rig mast106, a drive108, an elevated platform110, and a pipe ramp112. The well site102arranged generally below the elevated platform110may include a hydrocarbon well114(e.g., a well potentially capable of producing some form of an oil or a gas product) and a blowout preventer116that is generally coupled to the drive108.

In operation, the rig104may use the drive108to push a drill head (not shown) through hydrocarbon well114in order to clear a well bore in a subsurface hydrocarbon reservoir below. The rig104and/or other associated rigs (e.g., a completions rig) may subsequently engage in one or more completion operations in order to prepare the well bore for hydrocarbon production. For example, a cement liner may be poured to establish an impermeable annulus about the well bore for some or all of a depth of the well. Additionally, metal casing and other equipment may be put into the well bore, which may further serve to establish flow paths for hydrocarbons produced by the well, in addition to establishing certain flow paths for off-gas, and/or other produced fluids of the well114. As described in greater detail herein in reference toFIGS.3and4, enhanced recovery operations, including fracking operations may be used to induce a flow of hydrocarbon from the well114.

With continued reference toFIG.1, the drilling operations may produce a volume of water, mud, and/or other debris. The system100ofFIG.1is shown as including schematically a separator system118, a mud gas separator120, an emitting pipe122, and a reserve pit124. Broadly, the separator system118includes any appropriate equipment to route produced materials (water, mud, gas) away from the well site114and upon removing gas therefrom, to dispose of said items in the reserve pit124. More generally, the reserve pit124may be any surface containment structure that is configured to hold one or more waste streams from the hydrocarbon well, including waste streams from drilling, completion, or production operations. In many cases, the reserve pit124is formed from an earthen trench dug into the ground and lined with a synthetic, impermeable material to prevent seepage of any liquids into the ground. Accordingly, while the reserve pit124is depicted for purposes of illustration inFIG.1as being associated with drilling operations, it will be appreciated that the reserve pit124may be used to capture substantially any liquid waste stream from hydrocarbon operations, including produced water and/or a recirculated form of fracturing fluid, among other waste streams.

FIG.1further shows schematically certain equipment that may be used in conjunction with the drilling operations100, including a generator system130, pumps138, and electrical conduits134,136. The pumps136are one example type of equipment that may require electrical power in order to operate and support the drilling of the well site102. For example, the pumps136may provide a critical pressurized flow of fluids (including mud) to the drilling site in order for the drive108to successfully cause the drill head to drill or clear out the well bore. In other examples, other types of equipment may be present, including accumulators, compressors, sensors, actuators, control rooms and the like, based on a stage of operation of the hydrocarbon operations. The pumps138any other equipment may be electrically powered by power generated at the generator system130. In convention systems, the generator system130may include a bank of diesel generators and/or a connection to a local power grid. The generator system130may in addition to or in the alternative, include an integral MSR132. The integral MSR132may generally be any deployable nuclear reactor system, as defined herein, that is capable of producing a heat output generated from fission reactors that occur therein. In the example ofFIG.1, the integral MSR132is shown schematically as transmitting an electrical output to pumps138through conduit134, and more generally to any other equipment of the system via the system connection136. Additionally or alternatively, the integral MSR132may further be used to provide a heat output to various other deployable components (e.g., such as a deployable desalination unit, deployable electrical generator unit, deployable hydrogen production unit, and/or deployable chemical production unit, if utilized.)

Turning toFIG.2, one example deployable nuclear reactor is shown for purposes of illustration, an integral MSR200. The integral MSR200may be or be associated with the integral MSR132described above in relation toFIG.1and/or any of the deployable MSRs described herein. Broadly, the integral MSR200may include an integrally constructed vessel204, a critical region208, a critical volume210, a subcritical region212, a subcritical volume214, a drain tank section220, an internal barrier222, a fuel salt passage224, a reactor section240, and a heat exchange section260. The common, integrally constructed vessel204may define both the critical region208and a subcritical region212. The critical region208may define a critical volume210for the circulation of fuel salt (e.g., a carrier salt including a fissionable material, such as LiF—BeF2—UF4) and for the housing of fission reactions occurring therein. Further, the subcritical region212may define a subcritical volume214for the storage of fuel salt away from a reactor core or otherwise away from the critical region204.

As generally shown inFIG.2, the critical region208may circulate fuel salt along a circulation flow path therein including a flow203athrough a reactor section240where the fuel salt may generally be heated due to fission reactions occurring therein. As further shown inFIG.2, the critical region208may circulate the fuel salt along a circulation path therein including a flow203bthrough a heat exchange section260and back to the reactor section240for recirculation via the flow203a. At the heat exchange section260, heat may be removed from the fuel salt in order to circulate a cooler fuel salt back to the reactor section240so that the fuel salt may again be heated along the flow203a. The circulation of the fuel salt along the flows203a,203bmay proceed continuously in order to provide a generally constant, steady stream of heat from the fission reactions to the heat exchangers of the integral MSR200.

The integrally constructed vessel204is shown inFIG.2as including the subcritical region212therein, which may establish a drain tank section220of the integral MSR200. Accordingly, the integral MSR200may be operable to maintain fuel salt in both a critical state, and a subcritical state, within the same, integrally constructed vessel204. The subcritical volume214of the subcritical region212is shown separated from the critical volume210by an internal barrier222. The internal barrier222may further define a fuel salt passage224therethrough in order to establish a flow path for the fuel salt between the critical volume210and the subcritical volume214.

Fuel salt may be selectively held within the critical volume210and/or the subcritical volume214based on the maintenance of an inert gas pressure within each volume. For example, the critical volume210may be held at a pressure Pr(reactor section pressure) or Pht(heat exchange section pressure) and the subcritical volume214may be held at a pressure Pdt(drain tank section pressure). In the example ofFIG.2, where fuel salt may be circulated in the critical region208, the integral MSR200may operate to maintain the pressure Par at a value that is greater than the pressures Pr, Pht. Accordingly, the fuel salt passage224may be pressurized to mitigate or prevent the introduction of fuel salt into the subcritical volume214. As described herein, the pressures Par, Pr, PIA may be manipulated in various manners in order to control the disposition of the fuel salt between the critical region208and the subcritical region212.

FIG.2further shows additional implementation details of the integral MSR200for purposes of example. As shown inFIG.2, the integral MSR200includes an outer container280. The outer container280may be used to define a containment space about the vessel204. For example, the outer container280may be configured to fully receive the vessel204and define a thermal barrier between the vessel204and an external environment. The vessel204may therefore be arranged in the outer container280in order to define an annular space282between the vessel204and the outer container280. The annular space282may be held at a pressure Pv, which may be a vacuum pressure. In other cases, Pvmay be adapted based on the thermal requirements of the integral MSR200. Additionally or alternatively, the annular space282may be configured to receive gas that may be adapted for emergency cooling of the vessel204, among other uses.

Further, the drain tank section220is shown configured to hold the fuel salt in the subcritical volume214, which may generally be defined collectively by the internal barrier222, drain tank walls226, and floors228. With reference the internal barrier222, the internal barrier222may be a structural component that establishes a physical barrier and physical separation between fuel salt held in the critical volume210and fuel salt held in the subcritical volume214. In this regard, the internal barrier222may have a sufficient strength and rigidity in order to support a weight of the fuel salt within the critical region208without undue deformation or encroachment of the internal barrier222into or toward the subcritical volume214.

The internal barrier222may be adapted to permit the passage of fuel salt between the critical volume210and the subcritical volume214only via the fuel salt passage224defined through the internal barrier222. In order to permit the transfer of fuel salt between the critical volume210and the subcritical volume214, the drain tank section220may further include a transfer pipe230. The transfer pipe230may extend from the fuel salt passage222toward floors228of the drain tank section220. As shown inFIG.2, the floors228may be slopped to encourage fuel salt toward the transfer pipe230. For example, an end of the transfer pipe230may have a mouth232that is disposed adjacent to the floors228of the drain tank section220. In this regard, and as described in greater detail herein, fuel salt can be transferred from the subcritical volume214to the critical volume210until said fuel salt reaches an elevational level of the mouth232in the subcritical volume214.

With further reference to the reactor section240, the reactor section240may be configured to receive a volume of fuel salt from the drain tank section220and cause fission reactions that heat the fuel salt. For example, the reactor section240may generally include a reactor core242formed at least partially from a moderator material, such as a graphite material. The reactor core242may cause or otherwise facilitate the undergoing fission reactions in the critical region208. Accordingly, the reactor core242may be constructed in a manner to receive the fuel salt and to cause the fuel salt to be heated therein. In this regard, the reactor core242is shown as having one or more fuel salt passages that extends generally from a core bottom side to a core top side. As described herein, the fuel salt may be encouraged to travel through the fuel salt passage, and in so doing, the fuel salt may be heated by fission reactions. In turn, the peripheral sides of the reactor core242may be arranged in order to define an annulus between the reactor core242and the vessel204, through which the fuel salt may travel upon removal of heat from the fuel salt at the heat exchange section260, and for subsequent recirculation into the core242.

With further reference to the heat exchange section260, the heat exchange section260may be configured to receive a flow of the heated fuel salt from the reactor section240and remove heat therefrom. For example, the heat exchange section260is shown as having a heat exchanger262. The heat exchanger262may generally take of any of variety of forms in order to transfer heat from fuel salt of the critical volume210to a coolant salt or other medium that is held by the heat exchanger262. Fuel salt (such as that which has been heated from one or more fission reactions) may be routed to the heat exchanger262and exposed to a cooler medium therein to remove heat from the fuel salt. In this regard, the coolant pipe run therein (including a cold leg268aand a hot leg268bshown inFIG.2) may be in contact with the heated fuel salt that traverses through the heat exchanger262such that a coolant salt at an elevated temperature format (due to the transfer of heat from the fuel salt) may exit the heat exchanger262via the hot leg268b.

The integral MSR200may further include a variety of other components to support the operation of the reactor. With continued reference toFIG.2, the integral MSR200is shown as including a control rod284. The control rod284may be a calibrated piece of metal that is selectively lowered and raised into the reactor242in order to reduce or stop a nuclear reaction occurring therein. As further shown inFIG.2, the integral MSR200may include a fuel load line286. The fuel load line286may be a pipe or conduit that is operable to carry a fuel salt from an environment exterior to the integral MSR200to the subcritical volume214. For example, the fuel load line286may including a loading end286athat is arranged outside of the outer container280and that is adaptable to receive a load of fuel salt therein. The fuel load line286may further include a dispending end286bthat is arranged within the subcritical volume214. In this regard, the fuel salt received at the loading end286amay be routed to through the fuel load line286and to the subcritical volume214for dispensing thereto via the loading end286a.

As further shown inFIG.2, the integral MSR200may include a pair of inert gas lines, including a subcritical gas line287and a critical region gas line288. Each of the gas lines287,288may be operable to control a pressure in the vessel204. For example, the subcritical gas line287may have a loading end287athat is arranged outside of the outer container280and operable to receive a flow of inert gas for routing to a dispensing end287bthat is arranged within the subcritical volume214. Accordingly, a flow of inert gas can be controlled in order to control a pressure Pdtof the subcritical volume214, thereby controlling a pressure in the drain tank section220. Further, the critical gas line288may have a loading end288athat is arranged outside of the outer container280and operable to receive a flow of inert gas for routing to a dispensing end288bthat is arranged with the critical volume210. Accordingly, a flow of inert gas can be controlled in order to control a pressure Phtof the heat exchange section260of the critical volume210, and to control a pressure Prof the reactor section240of the critical volume210. In other examples, other configurations and components of the integral MSR200are contemplated herein to accomplish the functionality of the various deployable nuclear reactors and deployable plants and microgrids described herein.

With reference toFIG.3, a system300is shown is shown illustrating example equipment used in hydraulic fracturing operations. As described herein, hydraulic fracturing operations may be one type, or one category, of operations associated with the hydrocarbon operations described herein that are integrated with or supported by the deployable nuclear reactors of the present disclosure. Broadly, hydraulic fracturing uses a pressurized fluid (often including a fracturing slurry composed of water, a proppant, and a chemical additive) that is injected into the subsurface reservoir—“production zone”—to increase a permeability of the reservoir, and thereby support the flow of hydrocarbons therein to the surface. At least some quantity of the pressurized, fracturing fluid may be recirculated to the surface upon injection into a hydrocarbon well (e.g., well114). This recirculated fluid, which may include or be a produced water, may represent one waste stream associated with hydrocarbon operations. Using the systems and techniques described herein, for example with reference toFIGS.4and5, the produced water or other recirculated form of the fracturing fluid may be treated, desalinated, and repurposed for other higher uses, including for municipal use.

In the example of theFIG.3, the system300includes a bank of trucks304each fluidically coupled with a common line312via a pumping connection. The bank of trucks304may be illustrative of trucks uses to support a hydraulic fracturing operations, including trucks that operate to deliver fluids, pumps fluids, mix fluids, and/or control the deliver of fluids through the common line312and to the well head. Such fluids may include any one or more of a water, a proppant, a chemical additive and/or fluid that is used to form the hydraulic fracturing slurry. For purposes of illustration,FIG.3shows the common line312extending from the bank of trucks304to a skid316for delivery of the fracturing slurry to the well head. The skid316may include any appropriate collection of components may cooperate the control a delivery of the fracturing slurry to the well head. For example, the skid316may include a piping manifold that receives the fracturing slurry from the common line312and that routes the fracturing slurry to a first control system320aand a second control system320b. The first control system320amay include a first control valve324a, a first pressure regulating device328aand/or any other appropriate equipment to facilitate the delivery of a fracturing slurry flow332ato a first well head. Correspondingly, the second control system320bmay also include a second control valve324b, a second pressure regulating device328band/or any other appropriate equipment to facilitate the delivery of a fracturing slurry flow332bto a second well head.

With reference toFIG.4, an example well site400is shown, schematically, which may be configured to receive the fracturing slurry flow from the system300described above. For example, the well site400may include a representative well404. The well404may be any type of well configured to produce a hydrocarbons from a subsurface reservoir, including producing certain oil and gas hydrocarbons therefrom. The well site400is shown as having the well404arranged on ground406that sits about a subsurface408. The subsurface408may include a plurality of subsurface geological formations, including a production zone or production formation408a. The well404may including a well casing410that extends through the subsurface408and to the production formation408afor extraction of hydrocarbons therefrom. For example, the well404may be an at least partially horizontally drilled well including a production casing section412that extends a horizontal distance into the production formation from the main portion of the largely vertical well casing410. The production casing414may further including perforated holes414therethrough within the production formation408awhich may permit an injection flow416of hydraulic slurry to be emitted therethrough to impact the production zone408ageology and increase its permeability to thereby induce a flow of hydrocarbons from the production zone408a.

In connection with the foregoing operations, the well400is shown functionally associated with an injection module420, an off-gas module424, and a produced water module428. The injection module420may include one or more processes and associated equipment that are configured to deliver a flow of fluid to the well400for a variety of purposes. In one example, the injection module420may include a hydraulic fracturing operation (such as that described above with reference toFIG.3), and may therefore be adapted to deliver a stream of fracturing slurry to the well404. Additionally or alternatively, the injection module420may be configured to deliver other fluid flows to the well404, such as a stream flood, an acid wash, and/or other fluid that is adapted to enhance the recovery of the hydrocarbons from the production zone408a, any one of which may be powered by or integrated with the various deployable nuclear reactor systems described herein. Further, the produced water module428may include one or more operations configured to receive and process fluid that is returned form the well404. In some cases, such fluid may be a recirculated form of the injected fluid (e.g., a recirculated form of the fracturing fluid), particularly in a preproduction setting. In other cases, such fluid may be a water or other solution cut or separated from the oil or other hydrocarbons that are delivered by the well404. For example, the produced oil may include a percentage of water, which is separated from the oil, and routed to a different process than the produced oil, via the produced water module428. Further, the off-gas module424may include one or more operations configured to receive and process gases that are returned from the well404. As one example, during production or otherwise, the well404may be prone to emit certain methane gases from the well casing410. The off-gas module424receives such off-gases for treatment as a separate waste stream.

The deployable nuclear reactors described herein may be integrated with various hydrocarbon operations in a manner to treat waste streams from a well site, and to repurpose the waste stream into a higher use. For example, the deployable nuclear reactors may be integrated with the well404to treat and repurpose any produced water or other produced fluids from the produced water module428. Further, the deployable nuclear reactors may be integrated with the well404to treat and repurpose and off-gasses from the off-gas module424. However, the well404may be arranged in a generally remote location, such as being dozens or even hundred of miles from municipal services, which may hinder the ability to treat such waste streams.

To mitigate such concerns and to facilitate the treatment of the produced water, off-gas and/or other waste stream,FIG.5depicts a deployable plant500of the present disclosure. The deployable plant500may include any appropriate modules, components, systems, and subassemblies to treat and/or repurpose one or more waste streams of hydrocarbon operations using a deployable nuclear reactor. The deployable plant500may be substantially mobile and modular in construction. While the deployable plant500is shown, functionally, inFIG.5as one cohesive unit, in operation, the deployable plant500may include numerous trucks (e.g., semi tractor-trailers), skids, mobile connections, and so on such that the deployable plant500may be deployed, on demand to generally remote location associated with the hydrocarbon well. Further, while various modules and units of the deployable plant500are described herein, it will be appreciated that each such module and unit may, in turn, also be composed of numerous such trucks, skids, and mobile connections in support of the overall operation of the deployable plant500.

The deployable plant500includes a deployable nuclear reactor system504. The deployable nuclear reactor system504may be or include any of the nuclear reactor systems described herein, such as the integral MSR described in relation toFIG.2. In this regard, while the deployable nuclear reactor system504may be a molten salt nuclear reactor, other reactor types are possible, including, without limitation super critical water reactors, liquid sodium cooled reactors, helium or other gas cooled reactors, liquid metal cooled reactors, certain pressurized water reactors, among others. The deployable nuclear reactor system500, as with all of the units of the deployable plant500, may be a mobile unit that is configured to be transported to a first site, operated for a period of time, and moved to a second site for subsequent operation. Accordingly, the deployable nuclear reactor system504may be arranged to fit entirely on one or more tractor-trailers for transport using existing highway infrastructure. The deployable nuclear reactor system504may operate to produce heat, such as with the range of 600-750° C. At least some of this heat from the deployable nuclear reactor system504may be used by other units of the deployable plant500via heat outputs506a,506b,506c.

With further reference toFIG.5, the deployable plant500includes a deployable electrical generation unit520. The deployable electrical generation unit520may include any type of mobile unit that is configured to transform a heat into electricity, and may include one or more certain Rankine cycle generators, Stirling engines, thermoelectric generators, and/or other mechanisms that produce electricity from heat, including Brayton cycle generators and supercritical CO2generators, among others. Accordingly, and as shown inFIG.5, the deployable electrical generation unit520may receive the heat output506band, in turn produce one or more electrical outputs522a,522b,522c. Electrical outputs522b,522cmay be used to supply electricity to other deployable units of the deployable plant500, as described in greater detail below. Electrical output522amay be used to supply electricity to components and systems other than the deployable plant500, such as systems of the hydrocarbon operations that require electrical power, and/or to a power grid. In this regard, the deployable plant500is shown inFIG.5as including an electricity offtake module524. The electricity offtake module524may include any appropriate components configured to cooperate to take the electrical output522aand form an electrical power off-take output526, including certain breakers, switches, gears, routers, and the like. The electrical power off-take output526may then be used to directly supply electrical power to the hydrocarbon operations (e.g., such as the pumps138shown in relation toFIG.1) and/or to a grid or other commercial industrial use, as described in greater detail herein with reference toFIG.8.

With continued reference toFIG.5, the deployable plant500is shown as including a deployable desalination unit508. The desalination unit508may generally include any appropriate collection of components that is configured to treat and process any waste fluids from the various hydrocarbon operations described herein, such as those described inFIG.4associated with the produced water module428. By way of example, the deployable desalination module508shown inFIG.5is configured to receive a produced water input502a, such as a produced fluid or waste stream from any manner of hydrocarbon operation. The deployable desalination module508may operate to substantially reduce or eliminate a salt content of the produced water input502a. In some cases, the deployable desalination unit508may operate to filter, purify, or otherwise treat the produced water input502asuch that produced water input502amay be treated to at least the minimum acceptable standards for introduction into an municipal water treatment facility. The deployable desalination unit508may therefore produce a desalinated water output510that is routed to a desalinated water offtake512. The desalinated water offtake512may include any of a variety of components to facilitate the transfer of the desalinated water to another facility or use, including housing certain water pumps, tanks, ports, hoses, and so on. At least one water flow514may proceed from the desalinated water offtake512. In some cases, the water flow514may be a series of piping that leads the desalinated water to a municipal water source (as described herein in relation toFIG.8). In other cases, the water flow may additionally or alternatively represent a flow of water via trucks or other equipment from the deployable plant500, for example, where the water is moved off of the deployable plant500via truck.

In order to facilitate the foregoing operation, the deployable desalination unit508may use the heat output506afrom the deployable nuclear reactor system504. For example, the deployable desalination unit508may require receiving the heat output506ain the range of around 30 to 40 MWth, although other levels of thermal energy may be utilized Additionally or alternatively, the deployable desalination unit508may use the electrical output522cfrom the deployable electric generation unit520in support of the production of the desalinated water output510.

With continued reference toFIG.5, the deployable plant500is further shown as including a deployable hydrogen production unit532and a deployable chemical production unit536. The deployable hydrogen production unit532and the deployable chemical production unit536may collectively define a deployable gas processing system530. The deployable hydrogen production unit532may generally include any appropriate collection of components that are configured to treat and process any waste gases from the various hydrocarbon operations described herein, such as those described inFIG.4associated with the off-gas module424. For example, the deployable hydrogen production unit532may include a steam-methane reformer that uses a steam input and a methane input to produce hydrogen. Additionally or alternatively, water electrolysis or other technique may be used to produce hydrogen. By way of example, the deployable hydrogen production unit532shown inFIG.5is configured to receive an off-gas input502b, such as an off-gas or other gas waste stream from any manner of hydrocarbon operation. In one example, the deployable hydrogen production unit532may operate to transform a casing gas (e.g., a methane case, CH4) into hydrogen (H2) output534via a steam methane refining processes. In other cases, other processes and techniques may be used to produce hydrogen from the casing gas. The deployable hydrogen production module532may use the heat output506cfrom the deployable nuclear reactor system504to produce the hydrogen output534. For example, the deployable hydrogen production unit532may require receiving the heat output506cin the range of around 5 to 1 MWth, based on a volume of casing processed thereby. Additionally or alternatively, the deployable hydrogen production unit532may use the electrical output522bfrom the deployable electric generation unit520in support of the production of the hydrogen output534.

As further depicted inFIG.5, the deployable gas processing system530includes the deployable chemical production unit536. The deployable chemical production unit536may generally include any appropriate collection of components that are configured to produce one or more chemicals from a hydrogen gas feedstock supplied by the hydrogen output534. In one example, the deployable chemical production unit536may operate to transfer the hydrogen output534into an ammonia (NH3) or chemical product538via a Haber-Bosch process. In other cases, other processes and techniques may be used to produce an ammonia product and/or other chemical product for commercial or industrial uses. The deployable chemical production unit536may use the heat output506cfrom the deployable nuclear reactor system504to produce the chemical product538. For example, the deployable chemical production unit536may require receiving the heat output506cin the range of around 5 to 50 MWth based on a volume of the hydrogen processed thereby. Additionally or alternatively, the deployable chemical production unit536may use the electrical output522bfrom the deployable electrical generation unit520in support of the production of the chemical product538.

The deployable plant500may further include a chemical offtake540. The chemical offtake540may include any appropriate components and systems to prepare the chemical product538for delivery to and offtake to an end customer. For example, the chemical offtake540may include certain tanks, vessels, piping, pumps, and so on that facilitate the transfer of the chemical product538off of the deployable plant500via the chemical flow542. For the purposes of illustration, the chemical product538may be removed from the deployable plant500via a series of trucks that receive the chemical product538from holding tanks of the chemical offtake540. In this regard, the chemical flow542may represent the output of the chemical product via said trucks. Whereas, in other cases, the chemical flow542may be indicative of other outputs of the chemical product538, including via a direct piping connecting to another processing or holding facility external to the deployable plant500.

The deployable plant500ofFIG.5may used with a wide variety of well sites in remote locations to establish a micro-grid. For example, often hydrocarbon wells are drilled in clusters in a remote location due the presence of a concreted subsurface hydrocarbon reservoir there below. The deployable plants of the present disclosure may be deployed in the field to a remote location and proximal to or otherwise close to such clusters of hydrocarbon wells. In this manner, the deployable plants may be used to produce electrical power for, and to treat or repurpose waste streams for, multiple hydrocarbon wells, all in the geographic well cluster.

For example, and with reference toFIG.6, a remote region600is depicted including a plurality of well sites608which may be a first cluster of hydrocarbon wells. A deployable plant604may be provided proximal to the well sites608. The deployable plant604may be substantially analogous to the deployable plant500ofFIG.5and include any of the modules described herein. In this regard, the deployable plant604may be configured to supply electrical power to any hydrocarbon operations that occur on any of the well site608. Further, the deployable plant604may be configured to receive a flow of produced or wastewater from any of the well sites608for treating and reprocessing as described herein. Further, the deployable plant604may be configured to receive a flow of casing or off-gas from any of the well sites608for treating and reproposing as described herein. Accordingly, the deployable plant604may be operable to establish a microgrid602with the well sites608in which the deployable plant604may receive and/or transmit fluids, gases, and electricity therebetween along operative connections610. By arranging the deployable plant604proximal to the cluster of well sites608, the benefits of integrating the deployable nuclear reactor may be realized across multiple different hydrocarbon wells. And as additional wells are drilling in this cluster, the operative connections610can be extended to expand the micro-grid602as needed. In some cases, the operative connections610can be extended to abandoned wells in order to provide heat and/or thermal requirements to operations associated with mitigating and closing said abandoned wells.

The deployable plants of the present disclosure may be movable, as needed, to subsequent clusters of wells. For example, and as shown inFIG.7, a region700is depicted including a micro grid702. The microgrid702may be substantially analogous as the microgrid602and include a deployable plant704, a plurality of well sites708, and operative connections710; redundant explanation of which is omitted herein for clarity.FIG.7further illustrates, a second cluster of wells720at a second geographic location different from the first geographic location of the wells708. The second cluster of wells720may be sufficiently far from the deployable plant704that it would be inefficient to merely extend the operative connections710to the additional wells. Rather, the deployable unit704(or any other deployable unit described herein) may be moved to the deployable plant site722which may support establishing operative connections724between said deployable plant and the wells of the second cluster of wells720.

In some cases, the deployable plants of the present disclosure may be adapted to provide outputs to neighboring municipalities. For example, the deployable plants may be configured to desalinate, filter, purify and/or otherwise treat produced water from one or more hydrocarbon wells to a standard that permits the treated produced water to enter a municipal drinking water system. For example, and as shown inFIG.8, a region800is depicted including a microgrid802. The micro grid802may be substantially analogous to the microgrids602and702and include a deployable plant804, a plurality of wells sites808, and operative connections810; redundant explanation of which is omitted herein for clarity. FurtherFIG.8further illustrates neighboring municipalities820a,820b,820c. In one example, the deployable plant804of the micro grid802may be operable to transfer a treated produced water output to one or more of the municipality820avia a fluid connection824a, the municipality820bvia a fluid connection824b, or the municipality820cvia a fluid connection824c. The fluid connections824a,824b,824cmay be a flexible, synthetic or rolled piping that can be readily installed and removed and reassembled at a second location in order to move with and be adaptable to the position of the deployable plant804.

FIGS.9-12depicts various example energy and material balance requirements of the hydrocarbon operations and associated deployable nuclear reactor systems described herein. With reference toFIG.9, a chart900is shown illustrating example thermal requirements of certain hydrocarbon operations and associated deployable nuclear reactor systems, such as those described above in relation toFIGS.1-8. The chart900includes a thermal requirements axis904(MWth), values for which are plotted along a time axis908delineated in days. The time axis908may represent a time period that commences with onsite activities for drilling a hydrocarbon well, and proceeds through various stages of the well including hydraulic fracturing, completions, and production. The chart900includes data for various hydrocarbon operations, such as those listed the legend912. Operations that require electrical energy input have thermal energy requirements equal to the electrical energy requirements divided by the thermal efficiency of the electrical generating system used. By way of example, the chart900shows thermal requirements916, which may be the thermal requirements associated with the “Drill Rig.” The chart900further shows thermal requirements920, which may be the thermal requirements associated with the “Completion Pumps.” The chart900further shows thermal requirements924, which may be the thermal requirements associated with the “Desalination” operations. The chart900further shows thermal requirements928, which may the thermal requirements associated with the “Dewatering/Degassing” operations. The chart900further shows thermal requirements932, which may be the thermal requirements associated with the “Pumping Heating” operations. The chart900further shows thermal requirements936, which may be the thermal requirements associated with the operations for converting a casing gas to hydrogen, i.e., “CH4→H2,” operations. The chart900further shows thermal requirements940, which may be the thermal requirements associated with the operations for converting a hydrogen gas to ammonia, i.e., “H2→NH3,” operations. In some cases, the deployable nuclear reactor may also supply thermal energy to the “Lighting and Office Power,” which is not depicted on chart900due to the requirements for “Lighting and Office Power” being substantially lower than the other requirements shown in chart900.

With reference toFIG.10, a chart1000is shown illustrating example electrical requirements of certain hydrocarbon operations and associated deployable nuclear reactor systems, such as those described above in relation toFIGS.1-8. The chart1000includes an electrical requirements axis1004(MWe), values for which are plotted along a time axis1008. The time axis1008may represent a time period that commences with onsite activities for drilling a hydrocarbon well, and proceeds through various stages of the well including hydraulic fracturing, completions, and production. The chart1000includes data for various hydrocarbon operations, such as those listed the legend1012. By way of example, the chart1000shows electrical requirements1016, which may be the electrical requirements associated with the “Drill Rig.” The chart1000further shows electrical requirements1020, which may be the electrical requirements associated with the “Completion Prep” operations. The chart1000further shows electrical requirements1024, which may be the electrical requirements associated with the “Completion Pumps” operations. The chart1000further shows electrical requirements1028, which may the electrical requirements associated with the “Completion” operations. The chart1000further shows electrical requirements1032, which may be the electrical requirements associated with the “Production Prep” operations. The chart1000further shows electrical requirements1036, which may be the electrical requirements associated with the “Flowback” operations. The chart1000further shows electrical requirements1040, which may be the electrical requirements associated with the “Production” operations. In some cases, the deployable nuclear reactor may also supply electrical energy to the “Dewatering/Degassing,” “Lighting and Office Power,” and/or “Pumping and Heating” operations, each of which are not depicted on chart1000due to the electrical requirements of such generally being substantially lower than the other requirements shown in chart1000.

With reference toFIG.11, a chart1100is depicted illustrating an example produced water volume inventory associated the system ofFIG.9, or any generally with any of the hydrocarbon operations described herein. The chart1100includes a volume axis1104, values for which are plotted along a time axis1108. The time axis1108may represent a time period that commences with onsite activities for drilling a hydrocarbon well, and proceeds through various stages of the well including hydraulic fracturing, completions, and production. The chart1100further includes a curve1112that shows the volume of produced water inventory that may be expected during such hydrocarbon operations along the time axis1108, as measured in millions of gallons of water. As shown inFIG.11, after an initial period, the curve112reflects a decrease in water inventory over time as said water removed from the pond or other capture facility and is desalinated and treated for other uses.

With reference toFIG.12, a chart1200is depicted illustrating an example cumulative desalinated water produced and a cumulative ammonia produced associated with the system ofFIG.9, or any generally with any of the hydrocarbon operations described herein. The chart1200includes a volume axis1204, values for which are plotted along a time axis1208. The time axis1208may represent a time period that commences with onsite activities for drilling a hydrocarbon well, and proceeds through various stages of the well including hydraulic fracturing, completions, and production. The chart1200further includes a curve1212that shows the cumulative volume of desalinated water produced during such hydrocarbon operations along the time axis1208, as measured in millions of gallons of desalinated water. The chart1200further includes a curve1216that shows the cumulative volume of ammonia produced during such hydrocarbon operations along the time axis1208, as measured in tonnes of ammonia produced.

FIG.13depicts a flow diagram of a method1300of treating an output of a well site using nuclear reactors. At operation1304, a well site having a subsurface hydrocarbon well is operated. For example, and with reference toFIG.4, the well site400is operated, such as operating the representative hydrocarbon well404. Operating the well404may include performing any number of hydrocarbon operations, described herein, including operations associated with drilling, completions, hydraulic fracturing, or production. At operation1308, a produced water output is produced from the hydrocarbon well. For example, and with continued reference toFIG.4, the hydrocarbon operations performed on the well404may generate the produced water output428. In some cases, the produced water output may include a recirculated form of a pressurized fluid that is injected into the well404, such as a fracturing fluid.

At operation1312, a deployable plant is operated proximal to the well site. For example, and with reference toFIGS.4and5, the deployable plant500is operated proximal the well site400. In this regard, the deployable plant500may operate to receive and treat one or more outputs from the well404, including the produced water output428and/or the off-gas output424. Further, and as shown at operation1316, a heat output is produced from a deployable nuclear reactor system of the deployable plant. For example, and with continued reference toFIGS.4and5, the deployable plant500may operate the deployable nuclear reactor system504, as described herein. The heat generated from the deployable nuclear reactor system504may be used to support the processing and treatment of the produced water output and/or the off-gas output. In this regard, and as shown at operation1320, the heat output is used for one or more hydrocarbon operations. For example, and with continued reference toFIGS.4and5, the deployable nuclear reactor system504may supply the heat output506ato the deployable desalination unit508to support the processing and treatment of the produced water into the desalinated water, as described herein. In other examples, the method1300may continue with the deployable electric generation unit520producing an electrical output, and/or with the deployable gas processing system530producing a chemical product, as described herein in relation toFIG.5.

Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. The foregoing description, for purposes of explanation, uses specific nomenclature to provide a thorough understanding of the described examples. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described examples. Thus, the foregoing descriptions of the specific examples described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the examples to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.