Fresh water supply level control scheme for seamless integration of produced water & wastewater recycling system with aquifer water supply well system

Abstract

A method and a system are described that seamlessly integrate a recycled water treatment system with a water supply system from a water well to supply low salinity fresh water to be used by a petroleum processing facility. The control scheme allows for the recycled water treatment system as a primary source to supply water for process, utilities and other needs while ensuring no interruption in supply. This is achieved by integrating it through a control scheme to supply water from the water well as a supplemental source in case of disruption due to outage of the recycled water treatment system.

Description

BACKGROUND

[0001] Fresh water with low salinity is a key utility in the process of refining crude oil into a refined product. On average, a refinery in the United States uses about 1.5 barrels of water to process one barrel of crude oil, but the amount can vary depending on the facility's design. Most of the water used is for cooling purposes, as refining petroleum produces a lot of heat that can damage equipment. Water is also used for other purposes, including boiler feed water, fire protection, sanitary services, solvent recovery, removing brines, etc.

[0002] Gas-lift uses a source of high-pressure gas to lower the density of or “lift” production fluids such as oil, gas, and / or water to the surface. Gas-lift systems generally use an external source of gas which is injected into production tubing located in the production well. The gas mixes with the fluids in the production tubing. This reduces the density of the fluids until the mixture becomes light enough to flow using the available reservoir pressure.SUMMARY

[0003] In general, in one aspect, the invention relates to a method to supply fresh water. The method includes coupling a primary water source and a water storage tank, wherein the primary water source comprises a recycled water treatment system, coupling a supplemental water source and the water storage tank, wherein the supplemental water source comprises a water well, detecting that a level of stored water in the water storage tank being less than a normal level to generate a first result, in response to the first result, initiating treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, wherein the water storage tank supplies the stored water to a processing facility, detecting that a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result, in response to the second result, shutting off the treated fresh water from the recycled water treatment system into the water storage tank, detecting that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result, and in response to the third result, initiating produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, wherein the water storage tank continues to supply the stored water to the processing facility, wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

[0004] In general, in one aspect, the invention relates to a water supply control system to supply fresh water. The water supply control system includes a primary water supply line that couples a primary water source and a water storage tank, wherein the primary water source comprises a recycled water treatment system, a primary water source controller that controls the primary water supply line, a supplemental water supply line that couples a supplemental water source and the water storage tank, wherein the supplemental water source comprises a water well, a supplemental water supply line controller that controls the supplemental water supply line, and the water storage tank that stores the fresh water for supplying to a processing facility, wherein the primary water source controller comprises a water level sensor that detects a level of stored water in the water storage tank being less than a normal level to generate a first result, a first flow control valve inserted in the primary water supply line that, in response to the first result, opens for treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, and a flow rate controller that detects a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result, wherein the first flow control valve, in response to the second result, shuts off the treated fresh water from the recycled water treatment system into the water storage tank, and wherein the water level sensor further detects that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result, wherein, in response to the third result, the supplemental water supply line controller initiates produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, and wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

[0005] In general, in one aspect, the invention relates to an integrated water control system to supply fresh water. The integrated water control system includes a primary water source comprising a recycled water treatment system, a supplemental water source comprising a water well, and a water supply control system comprising a primary water supply line that couples the primary water source and a water storage tank, a primary water source controller that controls the primary water supply line, a supplemental water supply line that couples the supplemental water source and the water storage tank, a supplemental water supply line controller that controls the supplemental water supply line, and the water storage tank that stores the fresh water for supplying to a processing facility, wherein the primary water source controller comprises a water level sensor that detects a level of stored water in the water storage tank being less than a normal level to generate a first result, a first flow control valve inserted in the primary water supply line that, in response to the first result, opens for treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, and a flow rate controller that detects a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result, wherein the first flow control valve, in response to the second result, shuts off the treated fresh water from the recycled water treatment system into the water storage tank, and wherein the water level sensor further detects that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result, wherein, in response to the third result, the supplemental water supply line controller initiates produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, and wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

[0006] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0007] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.BRIEF DESCRIPTION OF DRAWINGS

[0008] Specific embodiments of the disclosed technology will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.

[0009] FIG. 1 shows a system in accordance with one or more embodiments.

[0010] FIG. 2 shows a method flowchart in accordance with one or more embodiments.

[0011] FIGS. 3A-3C show examples in accordance with one or more embodiments.DETAILED DESCRIPTION

[0012] Throughout the application, ordinal numbers (for example, first, second, third) may be used as an adjective for an element (that is, any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

[0013] It is to be understood that the singular forms “a,”“an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a fluid sample” includes reference to one or more of such samples.

[0014] Terms such as “approximately,”“substantially,” etc., mean that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0015] It is to be understood that one or more of the steps shown in the flowcharts may be omitted, repeated, and / or performed in a different order than the order shown. Accordingly, the scope of the invention should not be considered limited to the specific arrangement of steps shown in the flowcharts.

[0016] Although multiply dependent claims are not introduced, it would be apparent to one of ordinary skill that the subject matter of the dependent claims of one or more embodiments may be combined with other dependent claims.

[0017] For the purposes of the present disclosure, accompanying components that are conventionally used in fluid flow network, such as fluid level controllers, fluid flow controllers, fluid control valves, pumps and compressors, gas handling apparatuses, sensors, additional valves and electronic controllers, heat exchangers, and mixers, are not shown or discussed for the sake of simplicity, although these and many more apparatuses and systems would be included in an actual operating fluid flow network. One of ordinary skill in the art appreciates that such components may be included in the embodiments disclosed.

[0018] Embodiments disclosed herein generally relate to a method and a system to seamlessly integrate a recycled water treatment system with a water supply system from a water well to supply low salinity fresh water to be used by a petroleum processing facility. The control scheme allows for the recycled water treatment system as a primary source to supply water for process, utilities and other needs while ensuring no interruption in supply. This is achieved by integrating it through a control scheme to supply water from the water well as a supplemental source in case of disruption due to outage of the recycled water treatment system.

[0019] FIG. 1 shows a schematic diagram of a system in accordance with one or more embodiments. In particular, the system (100) is an integrated water supply system. In one or more embodiments, one or more of the modules and / or elements shown in FIG. 1 may be omitted, repeated, combined, and / or substituted. Accordingly, embodiments disclosed herein should not be considered limited to the specific arrangements of modules and / or elements shown in FIG. 1.

[0020] As shown in FIG. 1, the integrated water supply system (100) includes a recycled water treatment system (120) as a primary water source and a water well (110a) as a supplemental water source that are coordinated using a water supply control system (140) to supply fresh water to a processing facility (150), such as a petroleum processing facility.

[0021] In one or more embodiments, the recycled water treatment system (120) processes waste water and / or water from oil refining processes of the processing facility (150) to generate low salinity fresh water to return to the processing facility (150) for cooling and other utility purposes. The processes performed by the recycled water treatment system (120) include: (i) pretreatment processes (e.g., deoiling, filtration, etc.) to remove contaminants and achieve the required water quality specifications, (ii) heat transfer to achieve the desired temperature needed for desalinating the water, and (iii) desalination process to remove the dissolved solids to achieve the desired water salinity.

[0022] Due to the complexity of these water treatment and desalination processes, intermittent outages of the recycled water treatment system (120) are to be expected. Therefore, the supplemental water source is required as a backup to maintain uninterrupted water supply to the processing facility (150). Well water is ground water brought to the Earth's surface through a water well (110a) from an underground aquifer (a layer of water-bearing rock or sediment) (110b) far below the Earth's surface. The well water is referred to as produced water in the context that it is “produced” by the water well (110a) from the groundwater. For example, the water well (110a) may produce the well water using a gas lift system, an electrical submersible pump (ESP) driven by a variable frequency drive (VFD) motor or a fixed speed motor, or any other suitable mechanism for bringing water up through the well. The water production may be modulated using a flow control valve (FCV) that controls the amount of the produced water from the water well (110a). The FCV also allows a free running well to be used without gas lift or ESP.

[0023] Groundwater from the underground aquifer is s a non-reusable resource of strategic importance, particularly to arid regions such as a desert. The water supply control system (140) ensures seamless integration with the water well (110a) as the supplemental water supply in case of recycled water treatment system outage, facilitating the effort to conserve groundwater while maintaining reliability of the processing facility (150).

[0024] In one or more embodiments, the water supply control system (140) is coupled to the recycled water treatment system (120) via a primary water supply line (141) to receive treated fresh water. The water supply control system (140) is further coupled to the water well (110a) via a supplemental water supply line (142) to receive produced water. The received treated fresh water and the produced water are stored in a water storage tank (310) of the water supply control system (140).

[0025] In one or more embodiments, the water supply control system (140) includes a primary water source controller (141a) that controls the primary water supply line (141) to receive treated fresh water when the recycled water treatment system (120) is operating properly without disruption. The primary water source controller (141a) may include flow rate sensors, water level sensors, flow control valves, and associated controlling devices to control the primary water supply line (141).

[0026] In one or more embodiments, the water supply control system (140) includes a supplemental water supply line controller (142a) that controls the supplemental water supply line (142) to receive produced water from the water well (110a) during an outage or disruption in operation of the recycled water treatment system (120). The supplemental water supply line controller (142a) may include flow rate sensors, water level sensors, flow control valves, and associated controlling devices to control the supplemental water supply line (142).

[0027] In one or more embodiments, the integrated water supply system (100) provides uninterrupted water supply to the processing facility (150) using the method described in reference to FIG. 2 below.

[0028] FIG. 2 shows a flowchart in accordance with one or more embodiments disclosed herein. Specifically, the flowchart depicted in FIG. 2 illustrates a method to provide uninterrupted water supply to a processing facility by integrating primary and supplemental water supplies. One or more of the steps in FIG. 2 may be performed by the components of the system (100) discussed above in reference to FIG. 1. In one or more embodiments, one or more of the steps shown in FIG. 2 may be omitted, repeated, and / or performed in a different order than the order shown in FIG. 2. Accordingly, the scope of the disclosure should not be considered limited to the specific arrangement of steps shown in FIG. 2.

[0029] Initially in Step 200, a recycled water treatment system and a water well are coupled via a primary water supply line and a supplemental water supply line, respectively, to a water storage tank that supplies fresh water to a processing facility. The recycled water treatment system is used as a primary water source while the water well is used as the supplemental water source to back up the water supply to the processing facility during any outage or operation disruption of the recycled water treatment system.

[0030] In Step 201, a level of stored water in the water storage tank is detected as being less than a normal level to generate a first result. For example, the level may be sensed using a normal level water level sensor installed in the water storage tank.

[0031] In Step 202, in response to the first result, treated fresh water is initiated to flow from the recycled water treatment system into the water storage tank to replenish the stored water. For example, the flow of the treated fresh water may be initiated by opening a flow control valve of the primary water supply line. The flow control valve may be opened automatically in response to the normal level water level sensor output signal without user intervention.

[0032] In Step 203, a flow rate of the treated fresh water from the recycled water treatment system is detected as being disrupted to below a minimum usable flow rate to generate a second result. For example, the flow rate may be measured using a flow rate sensor of the primary water supply line. The disruption may be due to equipment malfunction, overload, lack of waste water to treat, etc. at the recycled water treatment system.

[0033] In Step 204, in response to the second result, the flow of treated fresh water is shut off from the recycled water treatment system into the water storage tank. For example, the flow of the treated fresh water may be shut off by closing the flow control valve of the primary water supply line. The flow control valve may be shut off automatically in response to the flow rate sensor output signal without user intervention. Accordingly, the stored water level reduces as fresh water flows from the water storage tank to the processing facility after the primary water supply line is shut off.

[0034] In Step 205, the level of the stored water in the water storage tank is detected as being reduced to below a minimum acceptable water storage level to generate a third result. The minimum acceptable water storage level represents the lowest amount of water in the water storage tank to supply sufficient fresh water for maintaining proper operation of the processing facility. For example, the level may be sensed using a minimum water level sensor installed in the water storage tank. As an example, the level setpoint which actives the backup system (from the water-well) may be set at 40% while the level controller which controls the flow of water from the produced water recycle system may be set at 50%.

[0035] In Step 206, in response to the third result, produced fresh water is initiated to flow from the water well into the water storage tank to further replenish the stored water. The water well now serves as the supplemental water source to allow the water storage tank to continue to supply the stored water to the processing facility during disruption or outage of the recycled water treatment system. During the disruption of the recycled water treatment system, the supplemental water source supplements the primary water source to maintain uninterrupted water supply to the processing facility.

[0036] In one or more embodiments, the produced fresh water is initiated to flow from the water well into the water storage tank by activating a gas lift system thus initiating a gas lifting process to bring the well water from the underground aquifer to the Earth's surface.

[0037] In one or more embodiments, the produced fresh water is initiated to flow from the water well into the water storage tank by activating an electrical submersible pump (ESP) to bring the produced fresh water from an underground aquifer to Earth's surface. For example, the flow rate of the produced fresh water may be modulated by adjusting a variable frequency drive of the ESP or by adjusting a flow control valve of the supplemental water supply line.

[0038] In one or more embodiments, the produced fresh water is initiated to flow from a free flowing water well into the water storage tank by turning on the flow control valve of the supplemental water supply line to bring the produced fresh water from an underground aquifer to Earth's surface.

[0039] In Step 207, the disruption of the recycled water treatment system is mitigated to restore the flow rate of the treated fresh water from the recycled water treatment system. That is, some action is taken in Step 207 to address the water flow from the primary water source into the storage tank. For example, a maintenance or repair crew may be dispatched to perform necessary maintenance or repair of the recycled water treatment system.

[0040] In Step 208, the treated fresh water is resumed to flow from the recycled water treatment system into the water storage once the disruption of the recycled water treatment system is mitigated. For example, the treated fresh water flow may be resumed by opening the flow control valve of the primary water supply line.

[0041] In Step 209, the produced fresh water is shut off from the water well into the water storage tank after the treated fresh water flow from the recycled water treatment system is resumed. For example, the produced water may be shut off by stopping the lift gas flow, turning off the ESP, or shutting off the flow control valve of the supplemental water supply line.

[0042] FIGS. 3A-3E show an implementation example in accordance with one or more embodiments. The implementation example shown in FIGS. 3A-3E is based on the system and method flowchart described in reference to FIGS. 1 and 2 above. In one or more embodiments, one or more of the modules and / or elements shown in FIGS. 3A-3E may be omitted, repeated, combined, and / or substituted. Accordingly, embodiments disclosed herein should not be considered limited to the specific arrangements of modules and / or elements shown in FIGS. 3A-3E.

[0043] FIGS. 3A-3E show schematic diagrams of an integrated water supply system (300a, 300b, 300c) according to legend (350). Each of the integrated water supply system (300a, 300b, 300c) uses a recycled water treatment system (120) as a primary water source and uses a water well (110a) as a supplemental water source to produce water from an underground aquifer (110b). The primary water source and the supplemental water source are controlled by the water supply control system (140) to cooperatively supply fresh water to a processing facility (150). The integrated water supply system (300a) and the water supply control system (140) include pressure, level, and flow control devices (PICs, LICs, and FICs) that are described below. According to the legend (350), inputs of these control devices are depicted as PV and outputs of these control devices are depicted as MV. In particular, PV corresponds to measured values of fluid pressure or fluid level, and MV corresponds to control signals.

[0044] As shown in FIG. 3A, the integrated water supply system (300a) uses the water well (110a) with a gas lift system (110) as the supplemental water source. Gas lift is an artificial lift system where gas (321a), referred to as lift gas, is injected into a produced well casing to help lift liquids up to the surface through the production tubing. The amount of produced water flowing into the supplemental water input (310a) of the water storage tank (310) is modulated by the controlled gas lift system (110) to supplement the recycled water treatment system (120), which is the primary fresh water source for the petroleum processing facility (150). For example, waste water from the petroleum processing facility (150) may be treated and desalinated by the recycled water treatment system (120) to supply treated fresh water (310b). The treated fresh water (310b) is supplied through a flow control valve FCV-A (311) to a water storage tank (310) which stores the fresh water. Flow control valve (FCV) is a valve that controls flow rate of the fluid flow.

[0045] The storage tank (310) is a fluid storage facility with a primary water input to receive water from a primary source and a supplemental water input to receive water from a supplemental source. The storage tank (310) includes a water output to supply a processing facility (150), and also includes a water level sensor to generate a sensor output representing the stored water level, denoted as PV of the storage tank (310). For example, the storage tank (310) may be a degassing vessel configured to remove hazardous vapors from the stored water to protect any processing equipment (e.g., tanks, towers, exchangers, separators, columns, piping, etc.) of the petroleum processing facility (150) that require degassing decontamination. The removal of the volatile hazardous vapors also prevents any potential of a flash fire or a more disastrous accident. Any remaining volatile gas (310d) may be used as recovered gas (322) or sent to a flare burner (323) to be burned. The recovered gas (322) may be sent to gas compression and sent to the petroleum processing facility (150). In particular, flaring is a common practice of controlled burning of excess natural gas associated with gas exploration, production, and processing operations. The flaring is controlled by the pressure indicator controller (PIC) (324a) and associated pressure control valve (PCV) (324b). PIC (324a) is a control device that generates a control signal, depicted as MV, to control fluid pressure. Pressure control valve (PCV) is a valve that controls pressure of the fluid flow in response to the PIC control signal. The PIC (324a) and PCV (324b) are part of a control loop (pressure transmitter, controller, actuated valve, etc.) that controls the pressure. The output (310c) of the stored fresh water is sent to the petroleum processing facility (150) using water pumps (305). The stored water level of the storage tank (310) is adjusted using level controllers level indicator controller (LIC)-A (301) and LIC-B (302), which are control devices that generate a control signal, depicted as MV, to control fluid level. The LIC-A (301) and LIC-B (302) are part of a control loop (level transmitter, controller, actuated valve, etc.) that controls the level. LIC-A (301) maintains the stored water level at the normal level setpoint by adjusting FCV-A (311), which controls the output flow from the recycled water treatment system (120). In one or more embodiments, the FCV-A (311) is an on / off valve. When the stored water level is below the normal level setpoint, the LIC-A (301) sends an output control signal through a priority selector (311a) to open the FCV-A (311) and receive treated fresh water from the recycled water treatment system (120) into the storage tank (310) to increase the stored water level. In one or more embodiments, the FCV-A (311) is an adjustable flow rate valve. When the stored water level is below the normal level setpoint, the LIC-A (301) sends an output control signal through a priority selector (311a) to increase the flow rate of the treated fresh water from the recycled water treatment system (120) into the storage tank (310) to increase the stored water level.

[0046] A minimum flow setpoint (i.e., threshold) of FIC-A (303) may be set by a user (e.g., a water supply system operator) to define a minimum usable flow rate to receive fresh water from the recycled water treatment system (120). FIC stands for flow indicator controller, which is a control device that generates a control signal, depicted as MV, to control fluid flow rate. If the output flow rate from the recycled water treatment system (120) is less than the setpoint of FIC-A (303) (i.e., minimum usable flow rate), the FIC-A (303) generates an output control signal to override the output control signal of the LIC-A (301) through the priority selector (311a). In one or more embodiments, the priority selector (311a) evaluates the output control signal of the FIC-A (303) with a higher priority than the output control signal of the LIC-A (301). In this context, the priority selector (311a) is referred to as the highest output (priority) selector. In one or more embodiments, priority selector (311a) corresponds to a manually performed logic rule that selects the highest output based on the control signal value. For example, if one controller sends an output of 30% and the other sends an output of 50%, then the valve FCV-A (311) will open at the higher of the two outputs, which is 50%. (Inventor, this sentence from your feedback comment is not clear. Please provide an example value of the setpoint of FIC-A (303) (i.e., minimum usable flow rate from recycled water treatment system) and example value of the setpoint of the LIC-A (301) (i.e., the normal water level of the degassing vessel) and then describe a first scenario when priority selector (311a) opens FCV-A (311) and a second scenario when priority selector (311a) closes FCV-A (311). In one or more embodiments, priority selector (311a) corresponds to a device that selects the highest output based on the control signal value according to the logic rule described above.

[0047] Based on the priority selector (311a), the FIC-A (303) shuts off the FCV-A (311) to stop any treated fresh water from the recycled water treatment system (120) when the recycled water treatment system (120) is unable to supply at least the minimum usable flow rate, e.g., during a process disruption or equipment outage of the recycled water treatment system (120). Accordingly, the recycled water treatment system (120) can be shut down or otherwise deactivated such that repairs and restoration can be performed. In other words, the recycled water treatment system (120) is used as the primary water source only when it is capable to supply at least the minimum usable flow rate of treated fresh water.

[0048] In case the recycled water treatment system (120) is not able to deliver at least the minimum usable flow rate and being deactivated as the primary water source, the stored water level in the storage tank (310) will decrease until it reaches the setpoint of LIC-B (302), which defines a minimum acceptable water storage level. When stored water level drops below the setpoint, LIC-B (302) transmits a setpoint into the flow controller FIC-B (304a) in a cascade control arrangement to define a lift gas rate for the gas lift system (110) to control the rate of lift gas (321a) injected into the water well (110a) to start the gas lifting process. In the gas lift system (110), the FIC-B (304a) generates a control signal based on the defined lift gas rate from LIC-B (302), where the control signal in turn adjusts the flow control valves (312) (FCV-B1, FCV-B2) to that maintains appropriate rate of lift gas (321a) injected into the water well (110a). Accordingly, the produced fresh water from water well (110a) is supplied to the storage tank (310) through the supplemental water input (310a) to maintain the stored water level above the minimum acceptable water storage level.

[0049] When the recycled water treatment system (120) is restored and resumes feeding treated water to the storage tank (310), the store water level will increase such that the LIC-A (301) and FIC-A (303) cooperatively opens the FCV-A (311) to reactivate the primary water source supply. When the stored water level is increased to exceed the minimum acceptable water storage level, i.e., the LIC-B setpoint, the LIC-B (302) and FIC-B (304a) collectively shut off the flow control valves (312) (FCV-B1, FCV-B2) such that the lift gas (321a) ceases to flow into the water well (110a). In other words, the supplemental water source is deactivated.

[0050] As shown in FIG. 3B, the integrated water supply system (300b) uses the water well (110a) with a variable frequency drive (VFD) electrical submersible pump (ESP) (321b) as the supplemental water source. Th VFD is a controller device that generates a variable frequency control signal to drive the motor of the ESP (321b) where the variable frequency is proportional to the measured flow rate of the produced water from the water well. The integrated water supply system (300b) differs from the integrated water supply system (300a) in the operation of LIC-B (302) and VFD (304b) to control the ESP (321b) instead of the operation of LIC-B (302) and FIC-B (304a) to control the lift gas injection rate of the gas lift system (110).

[0051] In case the recycled water treatment system (120) is not able to deliver at least the minimum usable flow rate and being deactivated as the primary water source, the stored water level in the storage tank (310) will decrease until it reaches the setpoint of LIC-B (302), i.e., the minimum acceptable water storage level. When stored water level drops below the setpoint, LIC-B (302) transmits a setpoint into the variable frequency drive (VFD) (304b) in a cascade control arrangement to control the motor speed of the ESP (321b). The output flow rate from the water well (110a) is dependent on the resultant motor speed of the ESP (321b). Accordingly, the produced fresh water from water well (110a) is supplied to the storage tank (310) through the supplemental water input (310a) to increase and maintain the stored water level above the minimum acceptable water storage level.

[0052] When the recycled water treatment system (120) is restored and resumes feeding treated water to the storage tank (310), the store water level will increase such that the LIC-A (301) and FIC-A (303) cooperatively opens the FCV-A (311) to reactivate the primary water source supply. When the stored water level is increased to exceed the minimum acceptable water storage level, i.e., the LIC-B setpoint, the LIC-B (302) and VFD (304b) collectively shut off the ESP (321b) such that no more produced fresh water flows from the water well (110a). In other words, the supplemental water source is deactivated.

[0053] As shown in FIG. 3C, the integrated water supply system (300c) uses the water well (110a), either as a free flowing well or equipped with a fixed speed electrical submersible pump (ESP) (321c), as the supplemental water source. The integrated water supply system (300c) differs from the integrated water supply system (300a) in the operation of FIC-B (304a) and FCV-B (304c) to control the produced water flow rate instead of the operation of LIC-B (302) and FIC-B (304a)) to control the lift gas injection rate of the gas lift system (110).

[0054] In case the recycled water treatment system (120) is not able to deliver at least the minimum usable flow rate and being deactivated as the primary water source, the stored water level in the storage tank (310) will decrease until it reaches the setpoint of LIC-B (302), i.e., the minimum acceptable water storage level. When stored water level drops below the setpoint, the ESP (321c) is turned on if it is installed. In the case of the free flowing water well where no ESP is installed, LIC-B (302) transmits a setpoint to the flow controller FIC-B (304a) in a cascade control arrangement to control the flow rate of produced water from the water well (110a) through the FCV-B (304c). In the case where a fixed speed ESP (321c) is present, the flow controller FIC-B (304a) also triggers the ESP (321c) to start when the stored water level drops below the setpoint of the backup system, and shutdown when it reaches the level of the primary water recycle system.

[0055] When the recycled water treatment system (120) is restored and resumes feeding treated water to the storage tank (310), the store water level will increase such that the LIC-A (301) and FIC-A (303) cooperatively opens the FCV-A (311) to reactivate the primary water source supply. When the stored water level is increased to exceed the minimum acceptable water storage level, i.e., the LIC-B setpoint, the LIC-B (302) and FIC-B (304a) collectively shut off the ESP (321c) and / or the FCV-B (304c) such that no more produced fresh water flows from the water well (110a). In other words, the supplemental water source is deactivated.

[0056] Embodiments disclosed herein provide seamless integration of a water treatment and desalination system to reduce groundwater consumption while ensuring a reliable supply of water for the oil process. More specifically, embodiments disclosed herein integrate a water treatment and recycle system with existing operations of using a well in order to provide uninterrupted water supply to a process facility.

[0057] Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Examples

Embodiment Construction

[0012]Throughout the application, ordinal numbers (for example, first, second, third) may be used as an adjective for an element (that is, any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

[0013]It is to be understood that the singular forms “a,”“an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a fluid sample” includes reference to one or more of such samples.

[0014]Terms such as “approximately,”“substantiall...

BACKGROUND

[0001] Fresh water with low salinity is a key utility in the process of refining crude oil into a refined product. On average, a refinery in the United States uses about 1.5 barrels of water to process one barrel of crude oil, but the amount can vary depending on the facility's design. Most of the water used is for cooling purposes, as refining petroleum produces a lot of heat that can damage equipment. Water is also used for other purposes, including boiler feed water, fire protection, sanitary services, solvent recovery, removing brines, etc.

[0002] Gas-lift uses a source of high-pressure gas to lower the density of or “lift” production fluids such as oil, gas, and / or water to the surface. Gas-lift systems generally use an external source of gas which is injected into production tubing located in the production well. The gas mixes with the fluids in the production tubing. This reduces the density of the fluids until the mixture becomes light enough to flow using the available reservoir pressure.SUMMARY

[0003] In general, in one aspect, the invention relates to a method to supply fresh water. The method includes coupling a primary water source and a water storage tank, wherein the primary water source comprises a recycled water treatment system, coupling a supplemental water source and the water storage tank, wherein the supplemental water source comprises a water well, detecting that a level of stored water in the water storage tank being less than a normal level to generate a first result, in response to the first result, initiating treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, wherein the water storage tank supplies the stored water to a processing facility, detecting that a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result, in response to the second result, shutting off the treated fresh water from the recycled water treatment system into the water storage tank, detecting that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result, and in response to the third result, initiating produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, wherein the water storage tank continues to supply the stored water to the processing facility, wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

[0004] In general, in one aspect, the invention relates to a water supply control system to supply fresh water. The water supply control system includes a primary water supply line that couples a primary water source and a water storage tank, wherein the primary water source comprises a recycled water treatment system, a primary water source controller that controls the primary water supply line, a supplemental water supply line that couples a supplemental water source and the water storage tank, wherein the supplemental water source comprises a water well, a supplemental water supply line controller that controls the supplemental water supply line, and the water storage tank that stores the fresh water for supplying to a processing facility, wherein the primary water source controller comprises a water level sensor that detects a level of stored water in the water storage tank being less than a normal level to generate a first result, a first flow control valve inserted in the primary water supply line that, in response to the first result, opens for treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, and a flow rate controller that detects a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result, wherein the first flow control valve, in response to the second result, shuts off the treated fresh water from the recycled water treatment system into the water storage tank, and wherein the water level sensor further detects that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result, wherein, in response to the third result, the supplemental water supply line controller initiates produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, and wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

[0005] In general, in one aspect, the invention relates to an integrated water control system to supply fresh water. The integrated water control system includes a primary water source comprising a recycled water treatment system, a supplemental water source comprising a water well, and a water supply control system comprising a primary water supply line that couples the primary water source and a water storage tank, a primary water source controller that controls the primary water supply line, a supplemental water supply line that couples the supplemental water source and the water storage tank, a supplemental water supply line controller that controls the supplemental water supply line, and the water storage tank that stores the fresh water for supplying to a processing facility, wherein the primary water source controller comprises a water level sensor that detects a level of stored water in the water storage tank being less than a normal level to generate a first result, a first flow control valve inserted in the primary water supply line that, in response to the first result, opens for treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, and a flow rate controller that detects a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result, wherein the first flow control valve, in response to the second result, shuts off the treated fresh water from the recycled water treatment system into the water storage tank, and wherein the water level sensor further detects that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result, wherein, in response to the third result, the supplemental water supply line controller initiates produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, and wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

[0006] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0007] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.BRIEF DESCRIPTION OF DRAWINGS

[0008] Specific embodiments of the disclosed technology will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.

[0009] FIG. 1 shows a system in accordance with one or more embodiments.

[0010] FIG. 2 shows a method flowchart in accordance with one or more embodiments.

[0011] FIGS. 3A-3C show examples in accordance with one or more embodiments.DETAILED DESCRIPTION

[0012] Throughout the application, ordinal numbers (for example, first, second, third) may be used as an adjective for an element (that is, any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

[0013] It is to be understood that the singular forms “a,”“an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a fluid sample” includes reference to one or more of such samples.

[0014] Terms such as “approximately,”“substantially,” etc., mean that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0015] It is to be understood that one or more of the steps shown in the flowcharts may be omitted, repeated, and / or performed in a different order than the order shown. Accordingly, the scope of the invention should not be considered limited to the specific arrangement of steps shown in the flowcharts.

[0016] Although multiply dependent claims are not introduced, it would be apparent to one of ordinary skill that the subject matter of the dependent claims of one or more embodiments may be combined with other dependent claims.

[0017] For the purposes of the present disclosure, accompanying components that are conventionally used in fluid flow network, such as fluid level controllers, fluid flow controllers, fluid control valves, pumps and compressors, gas handling apparatuses, sensors, additional valves and electronic controllers, heat exchangers, and mixers, are not shown or discussed for the sake of simplicity, although these and many more apparatuses and systems would be included in an actual operating fluid flow network. One of ordinary skill in the art appreciates that such components may be included in the embodiments disclosed.

[0018] Embodiments disclosed herein generally relate to a method and a system to seamlessly integrate a recycled water treatment system with a water supply system from a water well to supply low salinity fresh water to be used by a petroleum processing facility. The control scheme allows for the recycled water treatment system as a primary source to supply water for process, utilities and other needs while ensuring no interruption in supply. This is achieved by integrating it through a control scheme to supply water from the water well as a supplemental source in case of disruption due to outage of the recycled water treatment system.

[0019] FIG. 1 shows a schematic diagram of a system in accordance with one or more embodiments. In particular, the system (100) is an integrated water supply system. In one or more embodiments, one or more of the modules and / or elements shown in FIG. 1 may be omitted, repeated, combined, and / or substituted. Accordingly, embodiments disclosed herein should not be considered limited to the specific arrangements of modules and / or elements shown in FIG. 1.

[0020] As shown in FIG. 1, the integrated water supply system (100) includes a recycled water treatment system (120) as a primary water source and a water well (110a) as a supplemental water source that are coordinated using a water supply control system (140) to supply fresh water to a processing facility (150), such as a petroleum processing facility.

[0021] In one or more embodiments, the recycled water treatment system (120) processes waste water and / or water from oil refining processes of the processing facility (150) to generate low salinity fresh water to return to the processing facility (150) for cooling and other utility purposes. The processes performed by the recycled water treatment system (120) include: (i) pretreatment processes (e.g., deoiling, filtration, etc.) to remove contaminants and achieve the required water quality specifications, (ii) heat transfer to achieve the desired temperature needed for desalinating the water, and (iii) desalination process to remove the dissolved solids to achieve the desired water salinity.

[0022] Due to the complexity of these water treatment and desalination processes, intermittent outages of the recycled water treatment system (120) are to be expected. Therefore, the supplemental water source is required as a backup to maintain uninterrupted water supply to the processing facility (150). Well water is ground water brought to the Earth's surface through a water well (110a) from an underground aquifer (a layer of water-bearing rock or sediment) (110b) far below the Earth's surface. The well water is referred to as produced water in the context that it is “produced” by the water well (110a) from the groundwater. For example, the water well (110a) may produce the well water using a gas lift system, an electrical submersible pump (ESP) driven by a variable frequency drive (VFD) motor or a fixed speed motor, or any other suitable mechanism for bringing water up through the well. The water production may be modulated using a flow control valve (FCV) that controls the amount of the produced water from the water well (110a). The FCV also allows a free running well to be used without gas lift or ESP.

[0023] Groundwater from the underground aquifer is s a non-reusable resource of strategic importance, particularly to arid regions such as a desert. The water supply control system (140) ensures seamless integration with the water well (110a) as the supplemental water supply in case of recycled water treatment system outage, facilitating the effort to conserve groundwater while maintaining reliability of the processing facility (150).

[0024] In one or more embodiments, the water supply control system (140) is coupled to the recycled water treatment system (120) via a primary water supply line (141) to receive treated fresh water. The water supply control system (140) is further coupled to the water well (110a) via a supplemental water supply line (142) to receive produced water. The received treated fresh water and the produced water are stored in a water storage tank (310) of the water supply control system (140).

[0025] In one or more embodiments, the water supply control system (140) includes a primary water source controller (141a) that controls the primary water supply line (141) to receive treated fresh water when the recycled water treatment system (120) is operating properly without disruption. The primary water source controller (141a) may include flow rate sensors, water level sensors, flow control valves, and associated controlling devices to control the primary water supply line (141).

[0026] In one or more embodiments, the water supply control system (140) includes a supplemental water supply line controller (142a) that controls the supplemental water supply line (142) to receive produced water from the water well (110a) during an outage or disruption in operation of the recycled water treatment system (120). The supplemental water supply line controller (142a) may include flow rate sensors, water level sensors, flow control valves, and associated controlling devices to control the supplemental water supply line (142).

[0027] In one or more embodiments, the integrated water supply system (100) provides uninterrupted water supply to the processing facility (150) using the method described in reference to FIG. 2 below.

[0028] FIG. 2 shows a flowchart in accordance with one or more embodiments disclosed herein. Specifically, the flowchart depicted in FIG. 2 illustrates a method to provide uninterrupted water supply to a processing facility by integrating primary and supplemental water supplies. One or more of the steps in FIG. 2 may be performed by the components of the system (100) discussed above in reference to FIG. 1. In one or more embodiments, one or more of the steps shown in FIG. 2 may be omitted, repeated, and / or performed in a different order than the order shown in FIG. 2. Accordingly, the scope of the disclosure should not be considered limited to the specific arrangement of steps shown in FIG. 2.

[0029] Initially in Step 200, a recycled water treatment system and a water well are coupled via a primary water supply line and a supplemental water supply line, respectively, to a water storage tank that supplies fresh water to a processing facility. The recycled water treatment system is used as a primary water source while the water well is used as the supplemental water source to back up the water supply to the processing facility during any outage or operation disruption of the recycled water treatment system.

[0030] In Step 201, a level of stored water in the water storage tank is detected as being less than a normal level to generate a first result. For example, the level may be sensed using a normal level water level sensor installed in the water storage tank.

[0031] In Step 202, in response to the first result, treated fresh water is initiated to flow from the recycled water treatment system into the water storage tank to replenish the stored water. For example, the flow of the treated fresh water may be initiated by opening a flow control valve of the primary water supply line. The flow control valve may be opened automatically in response to the normal level water level sensor output signal without user intervention.

[0032] In Step 203, a flow rate of the treated fresh water from the recycled water treatment system is detected as being disrupted to below a minimum usable flow rate to generate a second result. For example, the flow rate may be measured using a flow rate sensor of the primary water supply line. The disruption may be due to equipment malfunction, overload, lack of waste water to treat, etc. at the recycled water treatment system.

[0033] In Step 204, in response to the second result, the flow of treated fresh water is shut off from the recycled water treatment system into the water storage tank. For example, the flow of the treated fresh water may be shut off by closing the flow control valve of the primary water supply line. The flow control valve may be shut off automatically in response to the flow rate sensor output signal without user intervention. Accordingly, the stored water level reduces as fresh water flows from the water storage tank to the processing facility after the primary water supply line is shut off.

[0034] In Step 205, the level of the stored water in the water storage tank is detected as being reduced to below a minimum acceptable water storage level to generate a third result. The minimum acceptable water storage level represents the lowest amount of water in the water storage tank to supply sufficient fresh water for maintaining proper operation of the processing facility. For example, the level may be sensed using a minimum water level sensor installed in the water storage tank. As an example, the level setpoint which actives the backup system (from the water-well) may be set at 40% while the level controller which controls the flow of water from the produced water recycle system may be set at 50%.

[0035] In Step 206, in response to the third result, produced fresh water is initiated to flow from the water well into the water storage tank to further replenish the stored water. The water well now serves as the supplemental water source to allow the water storage tank to continue to supply the stored water to the processing facility during disruption or outage of the recycled water treatment system. During the disruption of the recycled water treatment system, the supplemental water source supplements the primary water source to maintain uninterrupted water supply to the processing facility.

[0036] In one or more embodiments, the produced fresh water is initiated to flow from the water well into the water storage tank by activating a gas lift system thus initiating a gas lifting process to bring the well water from the underground aquifer to the Earth's surface.

[0037] In one or more embodiments, the produced fresh water is initiated to flow from the water well into the water storage tank by activating an electrical submersible pump (ESP) to bring the produced fresh water from an underground aquifer to Earth's surface. For example, the flow rate of the produced fresh water may be modulated by adjusting a variable frequency drive of the ESP or by adjusting a flow control valve of the supplemental water supply line.

[0038] In one or more embodiments, the produced fresh water is initiated to flow from a free flowing water well into the water storage tank by turning on the flow control valve of the supplemental water supply line to bring the produced fresh water from an underground aquifer to Earth's surface.

[0039] In Step 207, the disruption of the recycled water treatment system is mitigated to restore the flow rate of the treated fresh water from the recycled water treatment system. That is, some action is taken in Step 207 to address the water flow from the primary water source into the storage tank. For example, a maintenance or repair crew may be dispatched to perform necessary maintenance or repair of the recycled water treatment system.

[0040] In Step 208, the treated fresh water is resumed to flow from the recycled water treatment system into the water storage once the disruption of the recycled water treatment system is mitigated. For example, the treated fresh water flow may be resumed by opening the flow control valve of the primary water supply line.

[0041] In Step 209, the produced fresh water is shut off from the water well into the water storage tank after the treated fresh water flow from the recycled water treatment system is resumed. For example, the produced water may be shut off by stopping the lift gas flow, turning off the ESP, or shutting off the flow control valve of the supplemental water supply line.

[0042] FIGS. 3A-3E show an implementation example in accordance with one or more embodiments. The implementation example shown in FIGS. 3A-3E is based on the system and method flowchart described in reference to FIGS. 1 and 2 above. In one or more embodiments, one or more of the modules and / or elements shown in FIGS. 3A-3E may be omitted, repeated, combined, and / or substituted. Accordingly, embodiments disclosed herein should not be considered limited to the specific arrangements of modules and / or elements shown in FIGS. 3A-3E.

[0043] FIGS. 3A-3E show schematic diagrams of an integrated water supply system (300a, 300b, 300c) according to legend (350). Each of the integrated water supply system (300a, 300b, 300c) uses a recycled water treatment system (120) as a primary water source and uses a water well (110a) as a supplemental water source to produce water from an underground aquifer (110b). The primary water source and the supplemental water source are controlled by the water supply control system (140) to cooperatively supply fresh water to a processing facility (150). The integrated water supply system (300a) and the water supply control system (140) include pressure, level, and flow control devices (PICs, LICs, and FICs) that are described below. According to the legend (350), inputs of these control devices are depicted as PV and outputs of these control devices are depicted as MV. In particular, PV corresponds to measured values of fluid pressure or fluid level, and MV corresponds to control signals.

[0044] As shown in FIG. 3A, the integrated water supply system (300a) uses the water well (110a) with a gas lift system (110) as the supplemental water source. Gas lift is an artificial lift system where gas (321a), referred to as lift gas, is injected into a produced well casing to help lift liquids up to the surface through the production tubing. The amount of produced water flowing into the supplemental water input (310a) of the water storage tank (310) is modulated by the controlled gas lift system (110) to supplement the recycled water treatment system (120), which is the primary fresh water source for the petroleum processing facility (150). For example, waste water from the petroleum processing facility (150) may be treated and desalinated by the recycled water treatment system (120) to supply treated fresh water (310b). The treated fresh water (310b) is supplied through a flow control valve FCV-A (311) to a water storage tank (310) which stores the fresh water. Flow control valve (FCV) is a valve that controls flow rate of the fluid flow.

[0045] The storage tank (310) is a fluid storage facility with a primary water input to receive water from a primary source and a supplemental water input to receive water from a supplemental source. The storage tank (310) includes a water output to supply a processing facility (150), and also includes a water level sensor to generate a sensor output representing the stored water level, denoted as PV of the storage tank (310). For example, the storage tank (310) may be a degassing vessel configured to remove hazardous vapors from the stored water to protect any processing equipment (e.g., tanks, towers, exchangers, separators, columns, piping, etc.) of the petroleum processing facility (150) that require degassing decontamination. The removal of the volatile hazardous vapors also prevents any potential of a flash fire or a more disastrous accident. Any remaining volatile gas (310d) may be used as recovered gas (322) or sent to a flare burner (323) to be burned. The recovered gas (322) may be sent to gas compression and sent to the petroleum processing facility (150). In particular, flaring is a common practice of controlled burning of excess natural gas associated with gas exploration, production, and processing operations. The flaring is controlled by the pressure indicator controller (PIC) (324a) and associated pressure control valve (PCV) (324b). PIC (324a) is a control device that generates a control signal, depicted as MV, to control fluid pressure. Pressure control valve (PCV) is a valve that controls pressure of the fluid flow in response to the PIC control signal. The PIC (324a) and PCV (324b) are part of a control loop (pressure transmitter, controller, actuated valve, etc.) that controls the pressure. The output (310c) of the stored fresh water is sent to the petroleum processing facility (150) using water pumps (305). The stored water level of the storage tank (310) is adjusted using level controllers level indicator controller (LIC)-A (301) and LIC-B (302), which are control devices that generate a control signal, depicted as MV, to control fluid level. The LIC-A (301) and LIC-B (302) are part of a control loop (level transmitter, controller, actuated valve, etc.) that controls the level. LIC-A (301) maintains the stored water level at the normal level setpoint by adjusting FCV-A (311), which controls the output flow from the recycled water treatment system (120). In one or more embodiments, the FCV-A (311) is an on / off valve. When the stored water level is below the normal level setpoint, the LIC-A (301) sends an output control signal through a priority selector (311a) to open the FCV-A (311) and receive treated fresh water from the recycled water treatment system (120) into the storage tank (310) to increase the stored water level. In one or more embodiments, the FCV-A (311) is an adjustable flow rate valve. When the stored water level is below the normal level setpoint, the LIC-A (301) sends an output control signal through a priority selector (311a) to increase the flow rate of the treated fresh water from the recycled water treatment system (120) into the storage tank (310) to increase the stored water level.

[0046] A minimum flow setpoint (i.e., threshold) of FIC-A (303) may be set by a user (e.g., a water supply system operator) to define a minimum usable flow rate to receive fresh water from the recycled water treatment system (120). FIC stands for flow indicator controller, which is a control device that generates a control signal, depicted as MV, to control fluid flow rate. If the output flow rate from the recycled water treatment system (120) is less than the setpoint of FIC-A (303) (i.e., minimum usable flow rate), the FIC-A (303) generates an output control signal to override the output control signal of the LIC-A (301) through the priority selector (311a). In one or more embodiments, the priority selector (311a) evaluates the output control signal of the FIC-A (303) with a higher priority than the output control signal of the LIC-A (301). In this context, the priority selector (311a) is referred to as the highest output (priority) selector. In one or more embodiments, priority selector (311a) corresponds to a manually performed logic rule that selects the highest output based on the control signal value. For example, if one controller sends an output of 30% and the other sends an output of 50%, then the valve FCV-A (311) will open at the higher of the two outputs, which is 50%. (Inventor, this sentence from your feedback comment is not clear. Please provide an example value of the setpoint of FIC-A (303) (i.e., minimum usable flow rate from recycled water treatment system) and example value of the setpoint of the LIC-A (301) (i.e., the normal water level of the degassing vessel) and then describe a first scenario when priority selector (311a) opens FCV-A (311) and a second scenario when priority selector (311a) closes FCV-A (311). In one or more embodiments, priority selector (311a) corresponds to a device that selects the highest output based on the control signal value according to the logic rule described above.

[0047] Based on the priority selector (311a), the FIC-A (303) shuts off the FCV-A (311) to stop any treated fresh water from the recycled water treatment system (120) when the recycled water treatment system (120) is unable to supply at least the minimum usable flow rate, e.g., during a process disruption or equipment outage of the recycled water treatment system (120). Accordingly, the recycled water treatment system (120) can be shut down or otherwise deactivated such that repairs and restoration can be performed. In other words, the recycled water treatment system (120) is used as the primary water source only when it is capable to supply at least the minimum usable flow rate of treated fresh water.

[0048] In case the recycled water treatment system (120) is not able to deliver at least the minimum usable flow rate and being deactivated as the primary water source, the stored water level in the storage tank (310) will decrease until it reaches the setpoint of LIC-B (302), which defines a minimum acceptable water storage level. When stored water level drops below the setpoint, LIC-B (302) transmits a setpoint into the flow controller FIC-B (304a) in a cascade control arrangement to define a lift gas rate for the gas lift system (110) to control the rate of lift gas (321a) injected into the water well (110a) to start the gas lifting process. In the gas lift system (110), the FIC-B (304a) generates a control signal based on the defined lift gas rate from LIC-B (302), where the control signal in turn adjusts the flow control valves (312) (FCV-B1, FCV-B2) to that maintains appropriate rate of lift gas (321a) injected into the water well (110a). Accordingly, the produced fresh water from water well (110a) is supplied to the storage tank (310) through the supplemental water input (310a) to maintain the stored water level above the minimum acceptable water storage level.

[0049] When the recycled water treatment system (120) is restored and resumes feeding treated water to the storage tank (310), the store water level will increase such that the LIC-A (301) and FIC-A (303) cooperatively opens the FCV-A (311) to reactivate the primary water source supply. When the stored water level is increased to exceed the minimum acceptable water storage level, i.e., the LIC-B setpoint, the LIC-B (302) and FIC-B (304a) collectively shut off the flow control valves (312) (FCV-B1, FCV-B2) such that the lift gas (321a) ceases to flow into the water well (110a). In other words, the supplemental water source is deactivated.

[0050] As shown in FIG. 3B, the integrated water supply system (300b) uses the water well (110a) with a variable frequency drive (VFD) electrical submersible pump (ESP) (321b) as the supplemental water source. Th VFD is a controller device that generates a variable frequency control signal to drive the motor of the ESP (321b) where the variable frequency is proportional to the measured flow rate of the produced water from the water well. The integrated water supply system (300b) differs from the integrated water supply system (300a) in the operation of LIC-B (302) and VFD (304b) to control the ESP (321b) instead of the operation of LIC-B (302) and FIC-B (304a) to control the lift gas injection rate of the gas lift system (110).

[0051] In case the recycled water treatment system (120) is not able to deliver at least the minimum usable flow rate and being deactivated as the primary water source, the stored water level in the storage tank (310) will decrease until it reaches the setpoint of LIC-B (302), i.e., the minimum acceptable water storage level. When stored water level drops below the setpoint, LIC-B (302) transmits a setpoint into the variable frequency drive (VFD) (304b) in a cascade control arrangement to control the motor speed of the ESP (321b). The output flow rate from the water well (110a) is dependent on the resultant motor speed of the ESP (321b). Accordingly, the produced fresh water from water well (110a) is supplied to the storage tank (310) through the supplemental water input (310a) to increase and maintain the stored water level above the minimum acceptable water storage level.

[0052] When the recycled water treatment system (120) is restored and resumes feeding treated water to the storage tank (310), the store water level will increase such that the LIC-A (301) and FIC-A (303) cooperatively opens the FCV-A (311) to reactivate the primary water source supply. When the stored water level is increased to exceed the minimum acceptable water storage level, i.e., the LIC-B setpoint, the LIC-B (302) and VFD (304b) collectively shut off the ESP (321b) such that no more produced fresh water flows from the water well (110a). In other words, the supplemental water source is deactivated.

[0053] As shown in FIG. 3C, the integrated water supply system (300c) uses the water well (110a), either as a free flowing well or equipped with a fixed speed electrical submersible pump (ESP) (321c), as the supplemental water source. The integrated water supply system (300c) differs from the integrated water supply system (300a) in the operation of FIC-B (304a) and FCV-B (304c) to control the produced water flow rate instead of the operation of LIC-B (302) and FIC-B (304a)) to control the lift gas injection rate of the gas lift system (110).

[0054] In case the recycled water treatment system (120) is not able to deliver at least the minimum usable flow rate and being deactivated as the primary water source, the stored water level in the storage tank (310) will decrease until it reaches the setpoint of LIC-B (302), i.e., the minimum acceptable water storage level. When stored water level drops below the setpoint, the ESP (321c) is turned on if it is installed. In the case of the free flowing water well where no ESP is installed, LIC-B (302) transmits a setpoint to the flow controller FIC-B (304a) in a cascade control arrangement to control the flow rate of produced water from the water well (110a) through the FCV-B (304c). In the case where a fixed speed ESP (321c) is present, the flow controller FIC-B (304a) also triggers the ESP (321c) to start when the stored water level drops below the setpoint of the backup system, and shutdown when it reaches the level of the primary water recycle system.

[0055] When the recycled water treatment system (120) is restored and resumes feeding treated water to the storage tank (310), the store water level will increase such that the LIC-A (301) and FIC-A (303) cooperatively opens the FCV-A (311) to reactivate the primary water source supply. When the stored water level is increased to exceed the minimum acceptable water storage level, i.e., the LIC-B setpoint, the LIC-B (302) and FIC-B (304a) collectively shut off the ESP (321c) and / or the FCV-B (304c) such that no more produced fresh water flows from the water well (110a). In other words, the supplemental water source is deactivated.

[0056] Embodiments disclosed herein provide seamless integration of a water treatment and desalination system to reduce groundwater consumption while ensuring a reliable supply of water for the oil process. More specifically, embodiments disclosed herein integrate a water treatment and recycle system with existing operations of using a well in order to provide uninterrupted water supply to a process facility.

[0057] Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Examples

Embodiment Construction

[0012]Throughout the application, ordinal numbers (for example, first, second, third) may be used as an adjective for an element (that is, any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

[0013]It is to be understood that the singular forms “a,”“an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a fluid sample” includes reference to one or more of such samples.

[0014]Terms such as “approximately,”“substantiall...

Claims

1. A method to supply fresh water, comprising:coupling a primary water source and a water storage tank, wherein the primary water source comprises a recycled water treatment system;coupling a supplemental water source and the water storage tank, wherein the supplemental water source comprises a water well;detecting that a level of stored water in the water storage tank being less than a normal level to generate a first result;in response to the first result, initiating treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water, wherein the water storage tank supplies the stored water to a processing facility;detecting that a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result;in response to the second result, shutting off the treated fresh water from the recycled water treatment system into the water storage tank;detecting that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result; andin response to the third result, initiating produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, wherein the water storage tank continues to supply the stored water to the processing facility,wherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

2. The method of claim 1, further comprising:mitigating a disruption of the recycled water treatment system to restore the flow rate of the treated fresh water from the recycled water treatment system;in response to restoring the flow rate,resuming the treated fresh water to flow from the recycled water treatment system into the water storage tank; andshutting off the produced fresh water from the water well into the water storage tank,wherein, during mitigating the disruption of the recycled water treatment system, the supplemental water source supplements the primary water source to maintain uninterrupted water supply to the processing facility.

3. The method of claim 2, wherein initiating the produced fresh water to flow from the water well into the water storage tank comprises:initiating a gas lifting process to bring the produced fresh water from an underground aquifer to Earth's surface.

4. The method of claim 2, wherein initiating the produced fresh water to flow from the water well into the water storage tank comprises:activating an electrical submersible pump (ESP) to bring the produced fresh water from an underground aquifer to Earth's surface.

5. The method of claim 4, wherein initiating the produced fresh water to flow from the water well into the water storage tank further comprises:adjusting, using a variable frequency drive of the ESP, a flow rate of the produced fresh water from an underground aquifer to Earth's surface.

6. The method of claim 4, wherein initiating the produced fresh water to flow from the water well into the water storage tank further comprises:adjusting, using a flow control valve coupled to the ESP, a flow rate of the produced fresh water from an underground aquifer to Earth's surface.

7. The method of claim 1,wherein the water storage tank comprises a degassing vessel, andwherein the recycled water treatment system processes waste water from the processing facility to generate the treated fresh water.

8. A water supply control system to supply fresh water, comprising:a primary water supply line that couples a primary water source and a water storage tank, wherein the primary water source comprises a recycled water treatment system;a primary water source controller that controls the primary water supply line;a supplemental water supply line that couples a supplemental water source and the water storage tank, wherein the supplemental water source comprises a water well;a supplemental water supply line controller that controls the supplemental water supply line; andthe water storage tank that stores the fresh water for supplying to a processing facility,wherein the primary water source controller comprises:a water level sensor that detects a level of stored water in the water storage tank being less than a normal level to generate a first result;a first flow control valve inserted in the primary water supply line that, in response to the first result, opens for treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water; anda flow rate controller that detects a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result,wherein the first flow control valve, in response to the second result, shuts off the treated fresh water from the recycled water treatment system into the water storage tank, andwherein the water level sensor further detects that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result,wherein, in response to the third result, the supplemental water supply line controller initiates produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, andwherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

9. The water supply control system of claim 8,wherein a disruption of the recycled water treatment system is mitigated to restore the flow rate of the treated fresh water from the recycled water treatment system,wherein, in response to restoring the flow rate,the first flow control valve opens to resume the treated fresh water to flow from the recycled water treatment system into the water storage tank, andthe supplemental water supply line controller shuts off the produced fresh water from the water well into the water storage tank, andwherein, during mitigating the disruption of the recycled water treatment system, the supplemental water source supplements the primary water source to maintain uninterrupted water supply to the processing facility.

10. The water supply control system of claim 9, wherein the supplemental water supply line controller comprises:a gas lift system that initiates, in response to the third result, a gas lifting process to bring the produced fresh water from an underground aquifer to Earth's surface.

11. The water supply control system of claim 9, wherein the supplemental water supply line controller comprises:an electrical submersible pump (ESP) that is activated, in response to the third result, to bring the produced fresh water from an underground aquifer to Earth's surface.

12. The water supply control system of claim 11, wherein the supplemental water supply line controller further comprises:a variable frequency drive of the ESP that adjusts a flow rate of the produced fresh water from an underground aquifer to Earth's surface.

13. The water supply control system of claim 11, wherein the supplemental water supply line controller further comprises:a second flow control valve coupled to the ESP that adjusts a flow rate of the produced fresh water from an underground aquifer to Earth's surface.

14. The water supply control system of claim 8,wherein the water storage tank comprises a degassing vessel, andwherein the recycled water treatment system processes waste water from the processing facility to generate the treated fresh water.

15. An integrated water control system to supply fresh water, comprising:a primary water source comprising a recycled water treatment system;a supplemental water source comprising a water well; anda water supply control system comprising:a primary water supply line that couples the primary water source and a water storage tank;a primary water source controller that controls the primary water supply line;a supplemental water supply line that couples the supplemental water source and the water storage tank;a supplemental water supply line controller that controls the supplemental water supply line; andthe water storage tank that stores the fresh water for supplying to a processing facility,wherein the primary water source controller comprises:a water level sensor that detects a level of stored water in the water storage tank being less than a normal level to generate a first result;a first flow control valve inserted in the primary water supply line that, in response to the first result, opens for treated fresh water to flow from the recycled water treatment system into the water storage tank to replenish the stored water; anda flow rate controller that detects a flow rate of the treated fresh water from the recycled water treatment system being disrupted to below a minimum usable flow rate to generate a second result,wherein the first flow control valve, in response to the second result, shuts off the treated fresh water from the recycled water treatment system into the water storage tank, andwherein the water level sensor further detects that the level of the stored water in the water storage tank being reduced to below a minimum acceptable water storage level to generate a third result,wherein, in response to the third result, the supplemental water supply line controller initiates produced fresh water to flow from the water well into the water storage tank to further replenish the stored water, andwherein the primary water source and the supplemental water source collectively maintain uninterrupted water supply to the processing facility.

16. The integrated water control system of claim 15,wherein a disruption of the recycled water treatment system is mitigated to restore the flow rate of the treated fresh water from the recycled water treatment system,wherein, in response to restoring the flow rate,the first flow control valve opens to resume the treated fresh water to flow from the recycled water treatment system into the water storage tank, andthe supplemental water supply line controller shuts off the produced fresh water from the water well into the water storage tank, andwherein, during mitigating the disruption of the recycled water treatment system, the supplemental water source supplements the primary water source to maintain uninterrupted water supply to the processing facility.

17. The integrated water control system of claim 16, wherein the supplemental water supply line controller comprises:a gas lift system that initiates, in response to the third result, a gas lifting process to bring the produced fresh water from an underground aquifer to Earth's surface.

18. The integrated water control system of claim 16, wherein the supplemental water supply line controller comprises:an electrical submersible pump (ESP) that is activated, in response to the third result, to bring the produced fresh water from an underground aquifer to Earth's surface.

19. The integrated water control system of claim 18, wherein the supplemental water supply line controller further comprises:a variable frequency drive of the ESP that adjusts a flow rate of the produced fresh water from an underground aquifer to Earth's surface.

20. The integrated water control system of claim 18, wherein the supplemental water supply line controller further comprises:a second flow control valve coupled to the ESP that adjusts a flow rate of the produced fresh water from an underground aquifer to Earth's surface.

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