INTEGRATED FUEL GAS HEATER FOR MOBILE FUEL CONDITIONING EQUIPMENT
A system mounted on a skid for use in fracturing operations is disclosed along with an associated method. The system includes a line heater on the skid to enable heating of fuel to be used with a turbine generator and includes one or more pressure regulators coupled to the line heater to enable adjustment of a pressure associated with the fuel.
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This application is a continuation of U.S. patent application Ser. No. 16/897,467, filed Jun. 10, 2020 titled INTEGRATED FUEL GAS HEATER FOR MOBILE FUEL CONDITIONING EQUIPMENT, which is related to and claims the benefit of priority from U.S. Provisional Application 62/859,334, filed Jun. 10, 2019, titled INTEGRATED FUEL GAS HEATER FOR MOBILE FUEL CONDITIONING EQUIPMENT, the entire disclosures of which are incorporated by reference herein for all intents and purposes.
FIELDAt least one embodiment pertains to improvements in fracturing operations. In at least one embodiment, the present disclosure describes integrated fuel gas heaters for mobile fuel conditioning equipment.
BACKGROUNDHydraulic Fracturing is a technique used to stimulate production from some hydrocarbon producing wells. The technique may involve injecting fluid using fluid pumps into a wellbore at a pressure sufficient to generate fissures in formation surrounding the wellbore. The fluid pumps that inject pressurized fluid into the wellbore are high pressure pumps referred to as fracturing pumps. The fracturing pumps are powered by diesel engines, but may alternatively be powered by other sources, such as by electric motors. Electric hydraulic fracturing operations use natural gas fuel generators to produce electricity to power the electric fracturing equipment, including the electric motors that power the fracturing pumps. These generators require fuel conditioning equipment, such as equipment is used to separate liquids, trap particles, regulate fuel pressure, meter fuel usage, and to ensure safe fracturing operations.
SUMMARYIn at least one embodiment, a system mounted on a skid for use in fracturing operations is disclosed. The system includes a line heater on the skid to enable heating of fuel to be used with a turbine generator and includes one or more pressure regulators coupled to the line heater to enable adjustment of a pressure associated with the fuel.
In at least one further embodiment, a method for supporting fracturing operations is also disclosed. The method includes positioning a line heater on a skid to enable heating of fuel to be used with a turbine generator. A step in the method includes coupling one or more pressure regulators to the line heater. Further, the method includes enabling the one or more pressure regulators to adjust a pressure associated with the fuel.
The present disclosure will be readily understood upon reading the detailed description of non-limiting embodiments of the present disclosure with the accompanying drawing, in which:
The foregoing aspects, features, and advantages of the present technology will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawing, wherein like reference numerals represent like elements. In describing the preferred embodiments of the technology illustrated in the appended drawing, specific terminology will be used for the sake of clarity. However, the technology is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
When a fracturing operation is scheduled, information is gathered about the location and the requirements for the fracturing operation at the location. Then various equipment must be brought together and moved to the location to be set up. The set up procedure may be long and arduous and may involve testing various features associated with the fracturing operation, as well as arranging various components across various skids, connecting the various components, electrically, communicatively, and fluidly, and certifying one or more of the connections.
One of the testing requirements may involve a determination of the quality of fuel gas, also referred to as fuel, that is to be used in a turbine generator of the fracturing operation. Further, the quality of the fuel may be affected by the environment (for instance, ambient temperature and pressure of the environment) as fracturing operations may largely rely on the same components, but with a wide range of configurations based in part on the extremes in the environment at the location where the fracturing operation is to be performed. In at least one embodiment, if the ambient temperature is below freezing, the fuel from a supply line will need to be conditioned, such as heated, to be able to make it efficient and productive in the turbine.
The determination of the quality of the fuel may include determination of presence of any undesired material in the fuel, determination of a temperature of the fuel, and a determination of a pressure associated with a flow of the fuel. With this information, the various components of for fracturing may be rearranged or engaged with hoses and pipes to address the quality of the fuel with respect to at least requirements of the turbine generator to function in an efficient manner. A manner of addressing the quality of the fuel is to perform a conditioning to adjust the impurities, to adjust its temperature, or to adjust its flowing pressure. Each of these features may also be relative; for instance, the temperature is adjusted relative to a working temperature or an environment temperature; and the pressure is adjusted relative to a working pressure or the environment pressure.
While conditioning fuel gas, equipment that is mounted on different skids or trailers may be engaged together or connected together using flexible gas hoses. The hoses may be expensive and time consuming to connect together or to connect between the equipment on a wellsite. Still further, the connections and the hoses require pressure testing and recertification every six months to meet industry standards. Individual components may need to be brought to the wellsite, may be required to be arranged, adjusted, and connected together, while residing on different skids; and may also require special handling, such as by use of a crane or forklift to set into place. An element of dangerous and a requirement for caution make the process time consuming. The size of the equipment requiring the different skids may limit available options.
In an example, individual components are brought to well sites on individual trailers and hard pipes or flexible hoses to be rigged up in between. These pipes and hoses are interconnecting pieces that may often be common points of failure. As such, additional testing and certifications are required before each use and at times during the usage of such a system. Line heaters in such systems were designed for maximum space usage and final scalable load. As a result, unreliable operations with regulator failures or frozen valves were some of the challenged faced of the system having multiple skids and connectors.
In at least one embodiment, the above referenced shortcomings may be addressed by enabling mobile fuel gas conditioning equipment (referred to also as mobile conditioning equipment or system, mobile fuel conditioning equipment or system, or mobile gas conditioning equipment or system) to be mounted on a skid, a trailer-bed (referred to also as a trailer), or in/on other mobile environments. In at least one embodiment, the conditioning equipment may be mobile and versatile as a result, but also, the fluid and other connections between various components may be long-term connections (such as, not requiring disconnection and reconnection, or other resetting at each wellsite). In at least one embodiment, the versatility is supported by multiple configurations now available to the mobile conditioning equipment that account for size and weight restrictions of a single skid or trailer and that accounts for redundancy, which then improves reliability and ability to operate the mobile conditioning equipment, when mobile, in all types of weather conditions. In at least an aspect, the mobile conditioning equipment mounted on a single skid are coupled together prior to use and during the use, but are also not decoupled except for cleaning operations. As a result, failures and certification requirements are minimized, as well as set up times are greatly reduced.
In at least one embodiment, larger diameter pipes can be used for lower pressure while smaller pipes can be used for high pressure to enable similar volume of fuel for conditioning, irrespective of the inlet pressure at the location. The line heater may be, therefore, designed with smaller 3″ (inch) diameter plumbing, thereby allowing for a smaller system that can fit onto a single trailer or skid with other components, such as the pressure regulators, valves, separators, flowmeters, instrumentation, safety equipment, plumbing, and walkways. A bypass tube at a larger diameter, such as 6″ size can be built-in to bypass the line heater, when it is not needed. These features enable a smaller equipment package for the system for mobile gas conditioning, while still allowing the conditioning skid to operate with low and high pressure supply gas. This is irrespective of flow restriction or size as the line heater, plumbing, regulators, and other equipment are sized to fit on a single trailer or skid.
In at least one embodiment, the line heater 116 is an indirect fired gas heater, such as a glycol bath, that is mounted on a skid. The indirect fired gas heater may use natural gas from a supply line 124 that is either in the environment or from a separate fuel skid to fuel a burner of the indirect fired gas heater. The burner heats a fluid bath of the line heater. The fluid bath may have glycol or other chemical having different temperature properties at one or more phases (such as liquid and vapor phases). In at least one embodiment, the fuel gas may be piped through the fluid bath from a supply line 102 that is either in the environment or from a separate fuel skid. The fuel gas from supply line 102 may pass through or bypass intermediate components of the conditioning skid before being piped through the fluid bath in a fuel pipe inside the fluid bath. The fluid bath being heated provides requisite temperature conditioning of the fuel gas for use with a turbine generator for generating electricity for a fracturing pump.
In at least one embodiment, the burner heats a container having glycol or the other chemical having the different temperature properties and a pump of the indirect fired gas heater is used to pump the glycol or the chemical around conditioning pipes wound around the fuel pipe having the fuel gas for the turbine generator. In this manner, a further element of safety and control many be achieved during mobile conditioning of the fuel gas as to the temperature requirements prior to being consumed by the turbine generator.
In at least one embodiment, the use of natural gas to heat the glycol or the other chemical removes requirement for electric heaters that may be used for mobile conditioning the fuel gas. As the area of operation is high flammable, use of the electric heaters may be dangerous as no flame should be encouraged near any natural gas carrying pipes. The line heater of the present disclosure is relatively safer to the electric heaters. Moreover, the present disclosure is also able to address an issue of the electrical power requirement that would have been required to achieve heating in a comparable electric heater on a skid. In at least one embodiment, the present disclosure is able to operate without a requirement for 100 kilowatts of power that would have otherwise been required to provide the heating that is provided by the line heater. Such power requirements would require a larger transformer, large power cable, and a shore power supply (such as a larger black start generator). In addition, such power would be required for the heater before the turbine is operating as the fuel gas requires proper heating and conditioning before the turbine can be started.
In at least one aspect, in the case of electric heaters to replace or provide redundancy support to the line heater, the heating elements of the electric heater (132 in
In at least one further embodiment, one of the additional components of the mobile conditioning system include the ESD valve 104, which may be bypassed via a first bypass line 106. In at least one embodiment, the ESD valve 104 valve is a safety valve, such as a large, fast acting valve that can close when an undesired condition is detected. In at least one embodiment, the undesired conditioning may be high gas pressure or may be equipment fire. The ESD valve 104 is design to cut-off the full supply quickly. In at least one embodiment, the cut-off occurs in about one second or less. In at least one aspect, the ESD valve 104 may be an electric or a pneumatic valve. For pneumatic operation, in at least one aspect, gas pressure, compressed air, or compressed nitrogen may be used. In at least one aspect, fuel gas supplied through the fuel pipe or line 102 is sufficient to operate the ESD valve 104. Further, in configurations where the part 100 of the mobile fuel gas conditioning system is not designed to handle fuel below 80 per square inch (psi), the ESD valve 104 may be operable with pressure as low as 50 psi.
In at least one embodiment, a flowmeter 108 can also be installed in part 100 of the system for mobile fuel gas conditioning. In at least one aspect, other flowmeters may be used elsewhere in the system, including before the outlet of the fuel gas, as conditioned, prior to being fed to the turbine generator. The flowmeter 108 is a first flowmeter before the first separator 110, and may be a Coriolis flowmeter that can accurately meter liquids and gases in the fuel gas prior to the line heater 116 and other conditioning components. The other flowmeters that may be used following the temperature and pressure conditioning components 116, 202, 204 (in
In at least one embodiment, one or more separators 114 may be used in conjunction with one or more separator vessels 120. For instance, a separator vessel 120 with separator 114 follows a debris strainer 108, after the fuel passes a flowmeter 110 or is bypassed around the flowmeter 110. The separator 114 and its separator vessel 120 may be used to separate undesired fluids from the fuel gas. In at least one aspect, any of the separator vessels may be also used to store adequate fuel gas volume from the fuel pipe or line 102.
In at least one embodiment, an emergency operation may rely on the stored fuel gas, in the event of the fuel supply being shut down for any reason. In at least one embodiment, in an emergency operation, a turbine of the turbine generator may idle for over 10 minutes from the stored fuel gas volume in one or more of separator vessels 120. In at least one embodiment, interconnecting pipes and hoses may share the stored fuel gas volume across the one or more separator vessels. In at least one embodiment, one or more debris strainers, such as debris strainer 108, may be provided to strain any debris from the fuel pipe or line 102 prior to passing the fuel through the one or more separators, such as separator 114.
In at least one embodiment, temperature probes can be placed in multiple locations in part 100 of a system for mobile fuel conditioning. The temperature probes are sensors that allow operators to understand the fuel conditions (e.g., relative temperatures) in the multiple stages of the mobile conditioning process as it flows from the fuel pipe or line 102 to the output of the line heater 116. In at least one embodiment, the line heater 116 may be a bypassable heater via third bypass line 118. In a situation where at least the fuel is sufficiently within temperature requirements of the turbine, there may be no need to further condition the fuel. In a situation where the fuel requires a determined level of temperature conditioning, this may be achieved by a mixing of fuel from a conditioned side output of the line heater 116 and from an unconditioned portion that is bypassed by the third bypass line 118.
In at least one embodiment, the part 100 of the mobile fuel gas conditioning system includes a redundant heating sub-system, a feature of which is the methanol or other chemical additive subsystem 122. The redundant heating sub-system includes a separator, such as separator 206 (
In at least one embodiment, the present disclosure enables the fuel lines following the line heater or the bypass line 118 to include ports to support the methanol or other chemical additive subsystem 122. The ports enable methanol injection into the fuel as a redundant anti-freeze measure for the fuel and, in general, liquids with in the gas stream comprising the fuel. The second separator 206 (in
In at least one embodiment, the separators 114, 206 in the fuel line, before and after the pressure reduction regulators, enable removal of liquid impurities from the fuel. Here impurities may refer to any undesired component of the fuel than meant for the turbine generator. In at least one aspect, the upstream separator 114 may be adapted to remove any water slugs and free liquids, while the downstream separator 206 may be adapted to remove liquid drop out from the conditioning process or any carry over additives or chemicals previously left from the first separator.
In at least one embodiment, the separators or the separator vessels may be associated with automatic dump valves with low level and high level switches to automatically drain liquids in the separator vessels. These switches may be electric or pneumatic with manual hand operated redundant valves. In at least one embodiment, manifolds may be provided to allow for the fuel gas inlet (at line 102), the fuel gas outlet (214 of
In at least one embodiment, to enable efficient drainage, drain lines may be sized for both 1″ and 2″ diameter pipes or outlets for adequate liquid draining. Further, the electrically operated automatic dump valves may be controlled by level switches. Manually operated hand valves may be also installed as backups in the event of a switch, PLC, or the automatic dump valve failure. The drain lines may be also adapted with small regulators to ensure that the pressure that is being “dumped” to a holding tank or respective separator vessel does not exceed the tank (or drain line's) rated pressure. One or more check valves may be installed to prevent pressure or liquids from flowing back into the separator vessels from the drain lines.
In at least one aspect, the separator vessels 114, 206 may be adapted with pressure rated liquid sight glasses, magnetic fluid floats, and magnetic level switches for sensing fluid level and for informing the operator. In addition, class ANSI 900# piping can be used on lines or piping prior to the pressure reduction regulators. This allows the conditioning skid to accept supply pressures exceeding about 1480 psi. To save weight, space, and costs, the ANSI class can be reduced to about 300# after pressure reduction. Any compression used may not be capable of exceeding 300# rating without additional regulation.
In at least one embodiment, when the skid is operating in a high pressure condition (such as a high pressure fuel supply), a high pressure gas regulator 202 regulates fuel gas to an intended pressure for the turbine. In at least one embodiment, one or more high pressure regulators 202 may be solely used to cut the gas pressure to requirements of the turbine requires. In at least one embodiment, the use of the high pressure regulator 202 is in conjunction with the use of the line heater as well to condition the temperature of the fuel. In at least one embodiment, when the skid is operating with a low pressure fuel supply, one or more low pressure regulators 204 will be used to regulate the gas pressure, and a compressor 208 may be used in conjunction to boost the gas pressure to the requirements of the turbine. In at least one embodiment, the one or more low pressure regulators 204 also ensures a consistent pressure for the compressor's 208 inlet. The skid of the present disclosure is able to handle pressures such as 200 psi, which is too low for the turbine, but may be too high for many compressor inlets. In at least an embodiment of such a situation having 200 psi, the gas pressure may be cut to 100 psi for the compressor, and the compressor boosts the gas pressure to 450 psi for the turbine. The present disclosure enables a skid to have fuel gas conditioning equipment that can handle gas pressure from 80 psi to 1480 psi, and that can condition the fuel gas to 450 psi at a temperature where liquids within the fuel gas does not drop out. In at least one embodiment, in addition, when the inlet gas pressure from the supply is too low, the compressor 208 may used to provide any required boost to the pressure.
In at least one embodiment, incoming fuel gas in fuel pipe 102 may be of a certain predetermined gas flow rate that is a low pressure gas flow rate of about 100 psi. In this case, the gas flow pipe having the low pressure gas regulator 204 is adapted to have flanges as large as 6″ diameter. In at least one embodiment, when incoming fuel gas in the fuel pipe 102 is of a certain predetermined gas flow rate that is a high pressure gas flow rate of about 1000 psi (and above), the gas flow pipe having the high pressure gas regulator 202 is adapted to have flanges of about 3″ or 2″ diameter. This enables the gas flow pipes to carry about the same volume irrespective of the pressure at the source. In at least one embodiment, for low pressure gas flow from a source, a 6″ pipe is able to achieve a feed 20,000 lbs/hr at 100 psi to the pressure regulators, while for a high pressure gas flow from a source, a 3″ pipe is used to achieve the same 20,000 lbs/hr of fuel feed to the pressure regulators at 1000 psi. A nominal pressure for the turbine is about 450 psi, and so the pressure adapters or regulators function to adjust the pressure as required from the low or the higher pressure to the nominal pressure.
In at least one embodiment, the line heater 116 and the pressure regulators 202, 204 work relative to each other. In at least one embodiment, the line heater 116 may be beneficial when the incoming fuel gas at fuel line 102 is at high pressure and when a reduction to a lower pressure is required. As the temperature of the gas will decrease when the pressure is reduced, liquids are caused to drop out of the gas, which can cause the regulators and other equipment, including much of the conditioning equipment on the skid, to freeze. The line heater ensures that this freezing effect does not occur when a pressure cut is applied. The separator 206 may be used to capture the liquids that dropped out without harm to the equipment. In at least one embodiment, the line heater ensures that it is less likely that liquids will form when the pressure cut occurs. In at least one embodiment, a two-stage high pressure regulator is used, but is represented as a high pressure regulator 202. In at least one aspect, the first higher pressure regulator of the two-stage high pressure regulator performs much of the pressure regulation (such as 75% of the pressure regulation), while the second higher pressure regulator ensures uniform pressure output of the fuel. In at least one embodiment, the present disclosure enables a mobile fuel conditioning system that can condition a 1200 psi incoming fuel gas supply to a pressure of about 450 psi for the turbine engine.
In at least one embodiment, there may be a range of acceptable pressures for the fuel gas to the turbine at about 300 to 600 psi, with 450 psi a nominal pressure for the turbine. In at least one aspect, the range of pressures for the source fuel gas supply may be from 100 to 1000 psi. When the 100 psi pressured fuel gas is supplied, the fuel gas bypasses the line heater, passes to the low pressure regulator that is also coupled to a compressor for raising its pressure to a steady 450 psi for the turbine. When the 1000 psi pressured fuel gas is supplied, the pressure is required to be dropped using the high pressure regulator to 450 psi. A roughly 1 degree temperature drop occurs for roughly 7 psi drop in pressure. The pressure drop therefore is substantial and may cause the temperature of the fuel to drop and to freeze the high pressure regulators. As such, the 1000 psi fuel gas needs to be heated prior to regulating the pressure of the fuel. The various conditioning equipment on the skid enables engagement of any one of the equipment suitable to the requirements of the supply gas relative to the turbine requirements; and particularly, without having to remove hoses, add new hoses, or reset any connections. Instead, valves may be adjusted to direct the fuel to the required equipment on the skid.
In at least one embodiment, pressure transmitters may be placed in multiple locations to allow technicians to safely operate and troubleshoot the equipment. Together with the temperature sensors, the mobile system for fuel conditioning may include one or more sensors associated with the line heater and the one or more pressure regulators. The one or more sensors are adapted to detect temperature or pressure information at one or more of an input and an output of the line heater and the one or more pressure regulators. In at least one embodiment, the one or more sensors are also adapted to transmit, via lines 438 (in
In at least one embodiment, a fourth bypass line 212 enables the one or more pressure regulators 202, 204 to be bypassable pressure regulators. In this configuration, if the incoming gas flow is at an expected pressure for the turbine generator, the pressure related conditioning may not be required. Alternatively, adjusting the pressure of the gas fuel may also have an effect on its temperature. In at least one aspect, the bypass lines represent bypass plumbing to circumvent unused or damaged components. As such, each pressure regulator, separator, meter, ESD valve, and other components in the mobile gas conditioning system can have a bypass pipe used to route around that component to support a form of redundancy or alterative functions.
In at least one embodiment, regulation of gas from higher pressure (such as, for example, over 1000 pounds per square inch (psi)) to lower pressure (such as, for example, under 500 psi) may cause liquid dropout from the pressure and temperature reduction. The dropout of liquid may result in problems with the generator engine (turbine, reciprocating), gas pressure regulators, pressure safety valves, piping, and/or separator vessels. This phenomenon may be associated with or described as the Joule-Thomson effect, or JT effect. The present disclosure addresses issues arising from the JT effect, such as the placement of the line heater in
In at least one embodiment, when the source pressure is high and pressure reduction is required, the present disclosure prevents freezing of the regulators by heating the fuel before pressure reduction is applied. For example, if the supply gas temperature is 60 degrees Fahrenheit (F) and the pressure reduction is expected to cause a 60 degrees F. temperature drop, the fuel can be heated from 60 degrees F. to 120 degrees F. After the regulation process, the gas temperature will be at 60 degrees F. again. Heating the gas above its dew point reduces liquid dropout during the regulation process. Furthermore, if any phase change occurs the liquids will be above the freezing point and will simply be trapped in the downstream separator.
In at least one embodiment, the fuel in fuel line 102 is subsequently conditioned to eliminate or reduce the JT effect to prevent component failure or other operational difficulties for the later components. In at least one embodiment, this is enabled by at least the line heater that is adapted for a small equipment footprint, such as the skid, along with the pressure regulators, and the redundancies offered. Such a system does not sacrifice equipment footprint on location, mobilization times, ergonomics, safety, or cost. The mobile fuel gas conditioning of the present system utilizes, in at least one embodiment, the components in the parts 100 and 200 of the system described with reference to
In at least one embodiment, the part 200 of the system may include ports at one or more locations that are adapted to receive an external compressor 208. In at least one embodiment, when the gas fuel is at a low supply pressure of about 100 psi in line 102 till the line heater 116, the line heater can be bypassed, but the other conditioning components, such as low pressure regulator 204, separators 114, 206, pressure safety valves 104, process flow valves 410, 416, 418 (
In at least one aspect, instead of the external compressor 208, a small compressor may be integrated into the fuel gas conditioner skid. The small compressor may replace the line heater for low pressure applications, as the heating requirement may be met by the pressure applied to the fuel, or may not be required for low pressure applications in at least one embodiment of the present disclosure. Furthermore, in at least one aspect, the small compressor may be installed parallel to the line heater, or may be installed before or after the line heater.
In at least one embodiment, the process flow valves 410, 416, 418 may be adjusted or set according to the fuel conditioning skid requirements for engaging the appropriate high or low pressure regulators, based in part on the project demands. The valves can also be used to set up the conditioning skid for low pressure, high pressure, or nominal condition operations prior to the operation, without having to handle hoses and connectors that may be subject to operation failures and may require certification as noted elsewhere in this disclosure.
In at least one embodiment, even though the parts 100 and 200 of the system are illustrated with a defined number of components, such as the two separators, the line heater and the two pressure regulators, more than the illustrated number of components may be used as suitable for a skid and the requirement for a project. In at least one embodiment, electric heat tracing may be provided on the pressure reduction (or high pressure) regulators, on pilot tubing and pilot valves, on the process valves, on condensate drain lines, on the piping downstream of the pressure regulators, and on any flow restrictive piping or devices. Such features can prove advantageous for winterization and for redundancy in the event that the line heater cannot provide enough heating or fails.
In at least one embodiment, the line heater is adapted to distribute or circulate heated glycol through a manifold to other upstream and downstream processes for heating or winterizing requirements. Glycol hoses, in at least one aspect, may be wrapped around piping, such as process valves, regulators, pilot tubing, pilot valves, and drain lines, to prevent condensation from freezing inside and outside of the pipe surface. This adaptable may supplement or replace the electric heat tracing. As such, in at least one aspect, heated glycol lines or hoses may be used instead of the electric heat tracing to provide additional heating to components before or after the line heater, other than being used to winterize the equipment. The glycol lines can be from the glycol bath on the line heater or from a secondary heat source that is either an electric heating element or a natural gas burner.
In at least one embodiment, the parts 100, 200 enable a system that is a trailerized fuel conditioning equipment system. While, a physical layout of the components of the parts 100, 200 may be different in a skid, than illustrated in
In at least one aspect, the compressor 210 may be integrated on the skid. Isolating valves (such as illustrated in
In at least one aspect, the second separator 206 can also be used for catching spillover from the first separator 114, if the first separator 114 fills too quickly or if its drain system fails. For instance, the bypass line 118 may be engaged to pass the fuel to the second separator 206, and the optional line output to return the fuel to the first separator 114 is engaged from the second separator 206. In at least one embodiment, the first separator 114 may be physically (and functionally) in the conditioning process before the line heater 116, as illustrated, but may also be after the first separator 114. In at least one aspect, an advantage of such an arrangement is that the line heater 116 is only sized to heat the fuel gas and is not required to heat any associated free liquids. This enables a further compact design for sizing on a skid. As such, the system in
In at least one embodiment, the person of ordinary skill reading the present disclosure will recognize that components such as a variable frequency drive (VFD), an electric motor, and a switch gear system may be required in addition to the illustrated components in
In at least one embodiment, gas supplied for use in fracturing operations may be in the range of 50-80 degrees Fahrenheit (F). In at least one embodiment, the mobile conditioning for the fuel gas may be a requirement at start-up. There may be no requirement to reduce pressure significantly or to perform additional heating in some aspects. In at least one embodiment, even with low environmental temperatures, once the gas is flowing, the temperature will be above 50 degrees F. In at least one embodiment, when the fuel supply is, however, significantly higher than manageable for the turbine, for instance, 1000+ psi, the line heater becomes beneficial for conditioning the fuel. In most instances of preforming a 500+ psi pressure cut, freezing of the liquids contained in the fuel, and consequently of the conditioning equipment, becomes likely. This may also be the case in summer environmental temperatures due to the gas temperature, after the regulators, being in the negative range.
In at least one embodiment, other conditioning components, including the debris strainer, the separators, the ESD valves, and the flowmeters may be positioned on one side of the trailer, illustrated as housing 406. In at least one embodiment, housing 406 houses a force draft burner to promote the heating of the fuel. In at least one aspect, multiple manual, remote, or automated valves 410, 416, 418 that may function as processes valves are illustrated as adjacent to the line heater 414 and the pressure regulators 422, 424. The valves 410, 416, and 418 are also adjacent to their respective bypass lines 408 (and the lines hosting the pressure regulators 422, 424). The valves on the lines hosting the pressure regulators 422, 424 enable the pressure regulators to be bypassable pressure regulators. The valves may be closers or within a part of the pressure regulators. An external line 430 provides either the natural gas other energy source required to power the line heater 408. In at least one embodiment, fuel for conditioning, distinct from the energy source to power the line heater 408 may be provided via fuel line 432.
In at least one embodiment, equipment following the pressure regulators are provided via housing 426. In at least one aspect, the equipment in housing 426 may include additional separators and may support the redundancy subsystems, including the methanol injector and the extractor (via an additional separator, for instance). The conditioned fuel may be provided via line 434 for the turbine and subsequent components (such as illustrated in
In addition, in at least one aspect, on-skid power sources as well as on-shore power connections for external power supplies may be integrated on the skid 402, either inside or outside of one or more housing 406, 426, for use with the system. Solar cells, thermoelectric generators, small reciprocating engine generators, or small turbine generators can be used to provide onboard power for metering, electric valves, electric heat tracing, and onboard lighting. In at least one additional aspect, electrical plugs can be installed to allow for shore power connections such as from a supplemental generator or from a large fracturing turbine.
In at least one aspect, the adjacent locations of the skids 402, 404 enables heat reclamation from the turbine exhaust of skid 404 to provide heating to the mobile gas conditioning equipment, such as a feature of the bath 414, on skid 402. This may be an aspect of cogeneration in regards to turbine engines. Superheated exhaust gases from the turbine may be ducted to the fuel conditioning skid 402, or to a heat exchanger, such as heat exchanger 412 that may be used to provide a heated medium to the mobile fuel conditioning equipment on skid 402.
In at least one embodiment, the present disclosure enables scaling so that the line heater and the regulators, on a single skid, are capable of handling about 30,000 lbs/hr or more of mass flow. Furthermore, in at least one aspect, the line heater is safe or suitable for hazardous areas, such as Class 1 Division 2 areas, and may be adapted for compliance with NFPA 70 codes.
In at least one embodiment, analog gauges may be used along with digital gauges or sensors to improve safety on the skid 402. The use of analog gauges also enables technicians working near the equipment, or working on the equipment, to see the status of the gas temperature and pressure without needing an additional display. This also ensures that operators can determine the status of the skid even if electrical power fails or is otherwise unavailable. In at least one aspect, fold out walkways with hand rails for maintenance and hand valve access may be included on the skid 402. These are supporting structures that may be deployed for onsite operation/maintenance and may be stowed for mobilization.
In at least one aspect, the PSVs may be installed at multiple locations to protect the lowest pressure rated component. In at least one instance, the lowest pressure rated component may be the piping, instrumentation, vessels, valves, fittings, hoses, or flanges. The lowest rated components may differ than the listing depending on the system and application requirements. In at least one embodiment, the line heater and other components that are integrated onto a single skid are also enclosed with a soft shell or hard shell to increase weather related durability, or can remain unenclosed.
In at least one aspect, a forced draft burner may be used with the line heater to increase the efficiency of the line heater from about 65% up to about 85%. The forced draft burner may be located within section 406 with insulated heat pipes to the fuel pipe area in the bath 414. The use of the forced draft burner only to promote efficiency of the line heater results in decreased fuel consumption to achieve the conditioning of the fuel, but can also decrease the physical footprint of the line heater on the fuel conditioning skid. This allows all of the components described for conditioning of fuel gas to fit onto a single 53′ trailer or skid that may be about 8.5′ wide. In at least one embodiment, a benefit realized by the present disclosure is compaction of the mobile gas conditioning equipment on the trailer or skid that results in a weight of the trailer or skid being under 30,000 lbs, which then removes any requirements for special travel permits.
In at least one embodiment, an electric motor with a softstarter or variable frequency drive can also be used to operate the electric motor for a blower of the forced draft burner (130 in
In at least one aspect, the system for mobile fuel conditioning includes the one or more sensors (128 in
In at least one aspect, the mobile fuel conditioning system includes one or more remote receivers 440 (in
In at least one aspect, the skid 402 for mobile fuel conditioning is configured for Ethernet and LTE® connections for data collection of process meters, instrumentation, and automated alerts. Serial and Ethernet data connections for automatic and manual (remote) valve controls can be included and can be controlled from a turbine control room or the datavan 436 (in
In at least one embodiment, the present disclosure enables collection and distribution of current temperature, pressure, and quality information associated with the fuel supplied to the turbine during operation. In addition, the present disclosure enables collection and distribution of environmental (such as, ambient) temperature, pressure, and other factors affecting efficient operation of the turbine. With the collected data, the present disclosure enables comparative data analysis and extrapolation to determine appropriate configuration settings of the line heater, the pressure regulators, and any associated components on a skid.
In at least one embodiment, for a new wellsite location, current data of the fuel and ambient conditions available at the wellsite may be input to an intelligent subsystem adapted to perform the data comparisons and extrapolation from the current data and the collected data. The intelligent system correlates and/or extrapolates from the collected data to predict pressure, temperature, and other requirements that would be able to condition the fuel available at the wellsite for optimum operation of a turbine at the wellsite.
In at least one embodiment, a current temperature of the fuel, the pressure of flow, and impurities or constituents within the fuel may be part of the current and the collected data, while an operating temperature, an operating pressure, an operating final constituents may form an operations part of the collected data. Then a relationship between the collected data and the operations part of the collected data is identified to a reasonable error (such as, +/−5%). The relationship is used to extrapolate from the current data to find whether a predicted operations part of the current data is acceptable. When the operations part of the current data is acceptable, temperature, pressure and fuel constituent information is extracted from the collected data corresponding to the extrapolated relationship, and is used as the setting for the equipment on the skid at the wellsite. As more operations are performed, the extrapolations become more accurate and the reasonable error may be reduced or used to weight the extracted data.
In at least one embodiment, the system discussed herein for implementing aspects in accordance with various embodiments are computer-based environments having hardware and software capabilities for intelligent computing. For instance, a computer-based environment may include human-machine interfaces, processors, memory components, and communication components for receiving input from external computers. Further, different computing environments may be used, as appropriate, to implement various embodiments. External computers may be used to interact with various embodiments and can include any appropriate device operable to send and receive requests, messages, or information over an appropriate network and convey information back to a user of the device. Examples of such external computers may include personal computers, smart phones, handheld messaging devices, laptop computers, and the like. The network can include any appropriate network, including an intranet, the Internet, a cellular network, a local area network, or any other such network or combination thereof. Components used for such a system can depend at least in part upon the type of network and/or environment selected. Protocols and components for communicating via such a network are well known and will not be discussed herein in detail. Communication over the network can be enabled by wired or wireless connections, and combinations thereof using communication component, such as discussed throughout this disclosure.
While the technology has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the technology. Furthermore, it is to be understood that the above disclosed embodiments are merely illustrative of the principles and applications of the present technology. Accordingly, numerous modifications can be made to the illustrative embodiments and other arrangements can be devised without departing from the spirit and scope of the present technology as defined by the appended claims.
Claims
1. A system for use in fracturing operations, the system comprising:
- a line heater with first diameter piping adapted to fit on a skid and to be used to condition fuel for a turbine generator; and
- one or more pressure regulators to receive second diameter piping that is different than the first diameter piping and adapted to the fit on the skid to support adjusting a pressure associated with the fuel for the turbine generator.
2. The system of claim 1, further comprising:
- a bypass line located on the skid and being of a third diameter piping that is different from the first diameter piping to bypass the line heater.
3. The system of claim 1, further comprising:
- a glycol bath, a glycol-based heat exchanger, or a bypassable indirect heating bath provided to function as the line heater through which a fuel pipe comprising the fuel passes to enable the heating of the fuel.
4. The system of claim 1, further comprising:
- a bypassable high pressure regulator or a bypassable low pressure regulator functioning as the one or more pressure regulators to enable the adjustment of the pressure associated with the fuel.
5. The system of claim 1, further comprising:
- a redundant heating sub-system comprising a methanol injector and a methanol extractor to support the heating of the fuel upon failure of a feature of the line heater.
6. The system of claim 1, further comprising:
- a redundant heating sub-system comprising an electric heater to support the heating of the fuel upon failure of a feature of the line heater.
7. The system of claim 1, further comprising:
- a forced draft burner associated with the line heater to promote the heating of the fuel.
8. The system of claim 1, further comprising:
- one or more sensors associated with the line heater and the one or more pressure regulators, the one or more sensors to:
- detect temperature or pressure information at one or more of an input and an output of the line heater and the one or more pressure regulators; and
- transmit the temperature or pressure information to a remote receiver of a datavan.
9. The system of claim 1, further comprising:
- one or more first valves associated with an inlet of the line heater to enable bypassing of the line heater; or
- one or more second valves associated with an inlet to the one or more pressure regulators to enable bypassing of the one or more pressure regulators.
10. The system of claim 9, further comprising:
- one or more remote receivers associated with the one or more first valves or the one or more second valves to enable the bypassing of the line heater or the one or more pressure regulators from an input of a datavan or from one or more sensors associated with the line heater or the one or more pressure regulators, the one or more sensors to detect temperature information or pressure information during operation of the system.
11. A method for supporting fracturing operations, the method comprising:
- conditioning fuel for a turbine generator using a line heater with first diameter piping adapted to fit on a skid; and
- adjusting a pressure associated with the fuel for the turbine generator using one or more pressure regulators adapted to receive second diameter piping that is different than the first diameter piping and adapted to the fit on the skid.
12. The method of claim 11, further comprising:
- enabling the fuel to bypass the line heater using a bypass line that is located on the skid and that is of a third diameter piping that is different from the first diameter piping.
13. The method of claim 11, further comprising:
- providing a glycol bath, glycol-based heat exchanger, or a bypassable indirect heating bath to function as the line heater;
- enabling the fuel to pass through a fuel pipe within the glycol bath or the glycol-based heat exchanger to perform the heating of the fuel.
14. The method of claim 11, further comprising:
- providing a bypassable high pressure regulator or a bypassable low pressure regulator to function as the one or more pressure regulators; and
- enabling the adjustment of the pressure associated with the fuel using the bypassable high pressure regulator or the bypassable low pressure regulator.
15. The method of claim 11, further comprising:
- supporting the heating of the fuel upon failure of a feature of the line heater using redundant heating comprising a methanol injector and a methanol extractor.
16. The method of claim 11, further comprising:
- supporting the heating of the fuel upon failure of a feature of the line heater using redundant heating comprising an electric heater.
17. The method of claim 11, further comprising:
- promoting the heating of the fuel using a forced draft burner associated with the line heater.
18. The method of claim 11, further comprising:
- associating one or more sensors with the line heater and the one or more pressure regulators;
- detecting temperature or pressure information using the one or more sensors at one or more of an input and an output of the line heater and the one or more pressure regulators; and
- transmitting the temperature or pressure information to a remote receiver of a datavan.
19. The method of claim 11, further comprising:
- associating one or more first valves with an inlet of the line heater to enable bypassing of the line heater; or
- associating one or more second valves with an inlet to the one or more pressure regulators to enable bypassing of the one or more pressure regulators.
20. The method of claim 19, further comprising:
- associating one or more remote receivers with the one or more first valves or the one or more second valves; and
- enabling, by the association of the one or more remote receivers, the bypassing of the line heater or the one or more pressure regulators by:
- one or more remote inputs from a datavan or from one or one or more second inputs from sensors associated with the line heater or
- the one or more pressure regulators used to detect temperature information or pressure information.
Type: Application
Filed: Sep 22, 2022
Publication Date: Jan 19, 2023
Applicant: U.S. Well Services, LLC (Houston, TX)
Inventors: Brandon Hinderliter (Houston, TX), Jared Oehring (Houston, TX)
Application Number: 17/950,166