An oil recovery and water reduction combined with multi-source heating system

Abstract

The present invention relates to the technical field of oil production and water reduction, and specifically to an oil production and water reduction combined with multi-source heating system, including an oil storage and water reduction separator, a liquid inlet is provided on one side of the top of the oil storage and water reduction separator, an exhaust port is provided in the middle of the top of the oil storage and water reduction separator, and a water outlet and an oil outlet are provided on one side of the bottom of the oil storage and water reduction separator. The oil storage and water reduction separator is used to receive produced fluid with a high water content in the oil well, remove the water phase and the gas phase by physical separation, and output the intermediate oil phase with a lower water content to the heating furnace. The separated high-temperature water phase is transported to a multi-source heat pump unit for heat recovery. Compared with the existing technology, the present application is provided with an oil storage and water reduction separator in conjunction with a waste heat recovery multi-source heat exchange unit to quickly remove most of the water phase in the produced fluid, reduce the burden of subsequent processing, improve transportation efficiency, and realize multi-source coordinated energy supply, reduce dependence on traditional fossil energy, improve energy utilization efficiency, and have good environmental protection and sustainability.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production and water reduction, and in particular to an oil production and water reduction combined with multi-source heating system. Background Art

[0002] In the current oilfield exploitation process, crude oil produced fluid generally has the characteristics of high water content and deep emulsification. Especially in the middle and late stages of exploitation, the water content in the produced fluid can be as high as over 90%. If it is directly transported to the joint station for processing without preliminary separation, it will not only increase transportation energy consumption and equipment wear, but also cause the processing system to be overloaded, affecting the overall operating efficiency and stability.

[0003] In existing technologies, most oil production systems typically use gas-fired furnaces or air-source heat pumps for centralized heating and separation. These systems lack front-end separation and water reduction mechanisms, resulting in a significant amount of redundancy in the water phase throughout the entire transportation and processing process. This not only increases overall operating costs but also reduces production safety.

[0004] At the same time, traditional heating systems generally rely on natural gas or oil boilers as heat sources, with a single energy structure, low energy efficiency, and failure to fully integrate renewable energy or waste heat resources, resulting in large-scale consumption of fossil energy, low heating efficiency, and high energy consumption indicators, which is not conducive to the realization of green oil field mining and energy conservation and carbon reduction goals. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose an oil production and water reduction combined with a multi-source heating system to solve the problem that existing oil production systems generally lack front-end water reduction and multi-source energy supply mechanisms, resulting in redundant water phase transportation, a single energy structure and increased energy consumption.

[0006] Based on the above objectives, the present invention provides an oil production and water reduction combined with multi-source heating system, including an oil storage and water reduction separator, wherein a liquid inlet is provided on one side of the top of the oil storage and water reduction separator, an exhaust port is provided in the middle of the top of the oil storage and water reduction separator, and a water outlet and an oil outlet are provided on one side of the bottom of the oil storage and water reduction separator. The oil storage and water reduction separator is used to receive produced fluid with high water content from the oil well, remove the water phase and the gas phase by physical separation, and output the intermediate oil phase with lower water content to the heating furnace. The separated high-temperature water phase is transported to the multi-source heat pump unit for heat recovery.

[0007] A waste heat recovery multi-source heat exchange unit, one side of which is connected to an oil production heating furnace;

[0008] a heating furnace connected to the oil outlet of the oil storage and water reduction separator, a pumping pump body being provided between the oil outlet and the heating furnace, and the heating furnace being capable of utilizing the waste heat recovery multi-source heat exchange unit to provide heat to increase the temperature of the exported crude oil;

[0009] Recharge wells, which are abandoned wells in the oil field or newly drilled wells. The layer of sewage recharged by the recharge wells is consistent with the oil-producing layer to prevent contamination of other layers;

[0010] An intermediate heat exchanger, one side of which is connected to the waste heat recovery multi-source heat exchange unit, and the other side is connected to the water outlet of the oil storage and water reduction separator. A pumping pump body is provided between the intermediate heat exchanger and the waste heat recovery multi-source heat exchange unit. The intermediate heat exchanger is used to reduce the temperature of the high-temperature water separated by the water reduction separator and then re-inject it into the re-injection well. The waste heat recovery multi-source heat exchange unit uses the heat absorbed from the intermediate heat exchanger to heat the oil production heating furnace;

[0011] A control unit, interconnected with the temperature sensors, flow meters, and pressure sensors within the waste heat recovery multi-source heat exchange unit, the heating furnace, and the oil storage and water reduction separator, for dynamically calculating heat source priorities and collaboratively scheduling each heat source based on real-time heat source output, oil temperature requirements, and re-injection pressure, providing real-time feedback on heat exchange efficiency and performing closed-loop control in conjunction with heat load response and energy efficiency evaluation;

[0012] Wherein, the oil storage and water reduction separator includes a cyclone separation component and a gravity sedimentation component.

[0013] Preferably, the waste heat recovery multi-source heat exchange unit includes:

[0014] Multi-stage heat exchanger, the first stage recovers water phase sensible heat, the second stage absorbs solar thermal energy and air source heat energy;

[0015] The water temperature control valve automatically adjusts the water flow according to the recharge well pressure to meet the following requirements:

[0016] ,

[0017] Among them, K=0.5−1.2 is the well pressure correction coefficient, It is the real-time data of the recharge well pressure sensor.

[0018] Preferably, the first stage of the multi-stage heat exchanger is a double-helix counter-current tube, the inner tube of the double-helix counter-current tube is for the water phase to flow, and the outer tube of the double-helix counter-current tube is for the oil phase to flow in the reverse direction.

[0019] Preferably, the waste heat recovery multi-source heat exchange unit includes a combination structure of a plate heat exchanger and a shell and tube heat exchanger, and is provided with a bypass valve group, which can dynamically switch different heat exchange circuits according to the inlet and outlet water temperature difference and flow demand to optimize the heat recovery efficiency.

[0020] Preferably, the heating furnace includes a heat source priority control strategy:

[0021] a. Prioritize waste heat as the main heat source, and the proportion of waste heat in the total heating energy should not be less than 80%;

[0022] b. When the waste heat supply is insufficient, other heat sources should be added in the following order and proportion:

[0023] ① Enable solar energy, which provides 10% of the total energy required, and enable air source heat pump, which provides 90% of the total energy required;

[0024] ② When the solar energy is insufficient, the air source heat pump's supplementary amount reaches 100% of the total supplementary energy required.

[0025] Preferably, the control unit includes an intelligent heat source collaborative scheduling module used in conjunction with the heating furnace to implement a dynamic energy allocation strategy.

[0026] Preferably, the control unit is provided with error closed-loop regulation logic, comprising the following steps:

[0027] S1: Collect the oil outlet temperature and target temperature in real time and calculate the temperature difference;

[0028] S2: Determine whether the error tolerance is exceeded, and if so, enter compensation control;

[0029] S3: Select one or more heat sources to participate in regulation according to the compensation intensity level;

[0030] S4: Recalculate the energy contribution rate and update the control coefficient every cycle;

[0031] S5: If the error does not return to zero for more than three cycles, the heat source call ratio will be locked to the current valid range and a fault prompt signal will be issued.

[0032] Preferably, the control unit is integrated with a thermal energy anomaly response mechanism. When the output power fluctuation of any heat source exceeds 30%, the re-injection pressure exceeds the limit, or the heat exchange efficiency is lower than 75%, the following response process is triggered: the redundant heat source is enabled to temporarily replace the main heat source; the fault point feature code is recorded and the anomaly information is pushed to the remote control platform; if the anomaly is not resolved within three consecutive cycles, it will automatically switch to the full-load operation mode of the air source heat pump and trigger an alarm signal at the same time.

[0033] Preferably, the water inlet of the oil storage and water reduction separator is provided with an inlet baffle for stabilizing the water flow and preventing subsequent liquid inflow from disturbing the liquid in the tank body. The oil storage and water reduction separator automatically separates water, oil and gas by gravity due to the different densities. The gas outlet is controlled by a pressure control valve to control the on-off of the gas pipeline. The crude oil with low water content and the separated high-temperature sewage pipeline are controlled by a liquid level control valve to control the size of the external transmission flow.

[0034] Preferably, the reinjection well meets the requirements of low-pressure reinjection and is provided with a filtering device and a degassing device for stabilizing the water flow and reducing the impurities and gas content of the reinjected sewage.

[0035] Beneficial effects of the present invention:

[0036] This oil production and water reduction combined with multi-source heating system can achieve efficient oil-water separation and energy recycling of produced fluids by providing an oil storage and water reduction separator in conjunction with a waste heat recovery multi-source heat exchange unit. The oil storage and water reduction separator uses a dual separation mechanism of cyclone and gravity to quickly remove most of the water phase in the produced fluid, reducing the burden of subsequent processing and improving transportation efficiency; the separated hot water enters the waste heat recovery multi-source heat exchange unit, and the heat in the water is recovered through heat exchange technology for heating crude oil for external transmission; at the same time, the system combines renewable energy sources such as solar energy and air source heat pumps to heat crude oil, realizing multi-source coordinated energy supply, reducing dependence on traditional fossil energy, improving energy utilization efficiency, and having good environmental protection and sustainability.

[0037] This oil recovery and water reduction combined with multi-source heating system is equipped with a control unit, which can realize dynamic coordination and compensation control of multiple heat sources. In the case of waste heat supply fluctuations, energy mutations or system abnormalities, it can quickly respond and automatically adjust the energy distribution ratio. By matching different heat source characteristics, such as solar energy rapid response and heat pump stable output, it effectively alleviates the intermittent problem of renewable energy; at the same time, an energy stability index is introduced to quantify the system safety margin; in addition, the control unit has an error closed-loop adjustment mechanism, which can dynamically adjust the heat source participation strategy according to the temperature difference to achieve high-precision temperature control; when the heat source is abnormal, the redundant heat source is automatically enabled, which effectively improves the stability, safety and energy efficiency of the system, and significantly reduces the fault response time and the frequency of manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 Schematic diagram of the system flow of the present invention;

[0040] Figure 2 This is a schematic diagram of the error closed-loop adjustment logic flow of the present invention;

[0041] Figure 3 Schematic diagram of the system flow of the present invention;

[0042] Figure 4 Schematic diagram of the thermal energy anomaly response mechanism flow chart of the present invention. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0044] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0045] like Figures 1 to 4As shown, the oil production and water reduction combined with multi-source heating system includes an oil storage and water reduction separator, a top side of the oil storage and water reduction separator is provided with a liquid inlet, a top middle portion of the oil storage and water reduction separator is provided with an exhaust port, a bottom side of the oil storage and water reduction separator is provided with a water outlet and an oil outlet, the oil storage and water reduction separator is used to receive produced fluid with high water content in the oil well, remove the water phase and the gas phase by physical separation, output the intermediate oil phase with lower water content to the heating furnace, and the separated high-temperature water phase is transported to the multi-source heat pump unit for heat recovery; a waste heat recovery multi-source heat exchange unit, one side of the waste heat recovery multi-source heat exchange unit is connected to the oil production heating furnace; a heating furnace, the heating furnace is connected to the oil outlet of the oil storage and water reduction separator, a pumping pump body is provided between the oil outlet and the heating furnace, the heating furnace can use the waste heat recovery multi-source heat exchange unit to provide heat to increase the temperature of the exported crude oil; a reinjection well, the reinjection well is a remodeling well for abandoned wells in the oil field or The new well is drilled, and the layer of the reinjection wastewater in the reinjection well is consistent with the oil-producing layer to prevent contamination of other layers; an intermediate heat exchanger, one side of the intermediate heat exchanger is connected to the waste heat recovery multi-source heat exchange unit, and the other side is connected to the water outlet in the oil storage and water reduction separator. A pumping pump body is provided between the intermediate heat exchanger and the waste heat recovery multi-source heat exchange unit. The intermediate heat exchanger is used to reduce the temperature of the high-temperature water separated by the water reduction separator and then reinject it into the reinjection well. The waste heat recovery multi-source heat exchange unit uses the heat absorbed from the intermediate heat exchanger to heat the oil production heating furnace; a control unit, the control unit is interconnected with the waste heat recovery multi-source heat exchange unit, the heating furnace and the temperature sensor, flow meter and pressure sensor in the oil storage and water reduction separator, and is used to dynamically calculate the heat source priority and coordinate the scheduling of each heat source according to the real-time heat source output, oil temperature demand and reinjection pressure, and to provide real-time feedback on the heat exchange efficiency and perform closed-loop control in combination with the heat load response and energy efficiency evaluation;

[0046] After being extracted from the oil well, crude oil enters the oil storage and water reduction separator through the liquid inlet in a state of high water content (about 90%). The physical separation of oil phase, water phase and gas phase is achieved inside the separator by controlling the oil-water density difference and flow rate difference. The upper gas phase is discharged and recovered through the exhaust port, and the bottom high-temperature water phase and the middle oil-containing liquid are respectively discharged from the water outlet and the oil outlet; the discharged water phase is transported to the intermediate heat exchanger with low heat loss, and its sensible heat is transferred to the waste heat recovery multi-source heat exchange unit through the heat exchange process. After the water temperature drops from about 50℃ to 40℃, it is pumped to the formation recharge well by the pumping pump. The recharge well is obtained by the transformation of newly drilled or abandoned oil wells. Its injection layer is consistent with the oil-producing layer to avoid contamination of other layers and maintain formation pressure; at the same time, the water from the intermediate The oil phase is sent into the heating furnace through the oil outlet. Under the coordinated scheduling of the intelligent control unit, the heating furnace gives priority to absorbing heat from the waste heat recovery multi-source heat exchange unit, and calls on renewable energy sources such as solar energy and air source heat pumps in turn according to the oil temperature demand and the available status of the heat source to achieve coordinated heating, raising the oil temperature from about 50°C to 60°C before exporting it to the joint station; in the above process, the control unit serves as the core scheduling module, collecting oil temperature, flow, pressure and output parameters of each heat source in real time, dynamically calculating the priority of the heat source and performing proportional scheduling, and at the same time establishing a heat load response model and energy efficiency evaluation mechanism, and combining heat exchange efficiency feedback to perform error closed-loop adjustment on the heat source output and pump operation, thereby ensuring the stability of the heating process, maximizing energy efficiency and the system's intelligent adaptability to operating conditions.

[0047] like Figure 1 As shown, the waste heat recovery multi-source heat exchange unit includes:

[0048] Multi-stage heat exchanger, the first stage recovers water phase sensible heat, the second stage absorbs solar thermal energy and air source heat energy;

[0049] The water temperature control valve automatically adjusts the water flow according to the recharge well pressure to meet the following requirements:

[0050] ,

[0051] Among them, K=0.5−1.2 is the well pressure correction coefficient, Real-time data of the recharge well pressure sensor;

[0052] The first stage of the multi-stage heat exchanger is a double-helix counter-current tube, the inner tube of which flows the water phase and the outer tube flows the oil phase in the reverse direction;

[0053] The advantage of this setting is that it achieves the dual effects of energy cascade utilization and flow optimization. The double-helix countercurrent pipe structure forms a strong convection heat exchange through the countercurrent flow of the inner and outer pipes, which reduces the water phase temperature from 50°C to 40°C. The sensible heat released is efficiently absorbed by the oil phase (increasing the oil temperature by 5-10°C), which is more than 70% higher than the traditional single-tube heat exchanger. The flow formula of the water temperature control valve is based on the dynamic correction of the well pressure. , it can accurately maintain the balance of the reinjection pressure, prevent the water channeling phenomenon caused by the formation pressure fluctuation, and at the same time ensure that the heat exchanger always operates in the optimal Reynolds number range (2000 < Re < 5000), avoiding the decrease in heat transfer efficiency caused by laminar flow. The arrangement of the water phase in the inner pipe and the oil phase in the outer pipe utilizes the high viscosity characteristics of the oil phase, and enhances the turbulence effect through the secondary circulation generated by the spiral flow channel, increasing the heat transfer coefficient to 2.3 times that of the traditional straight pipe and reducing the pumping energy consumption.

[0054] Such as Figure 1 shown, the waste heat recovery multi-source heat exchange unit includes a combined structure of a plate heat exchanger and a shell-and-tube heat exchanger, and a bypass valve group is set, which can dynamically switch different heat exchange circuits according to the temperature difference and flow demand between the inlet and outlet to optimize the heat recovery efficiency;

[0055] The plate heat exchanger is suitable for rapid heat exchange under large temperature difference conditions and can efficiently handle large-flow fluids; the shell-and-tube heat exchanger is more suitable for stable heat exchange of small temperature difference and high-viscosity fluids. The advantages of the two complement each other, significantly improving the heat recovery efficiency of the overall system. The intelligent bypass valve group can automatically adjust the flow path according to the real-time working condition parameters, preferentially use the plate heat exchanger when the temperature difference is large, and automatically switch the pipeline when the flow fluctuates greatly, ensuring that the system is always in the best operating state, avoiding energy waste and ensuring heat exchange stability.

[0056] Such as Figure 1 、 Figure 4 shown, the heating furnace includes a heat source priority control strategy:

[0057] (a) Priority is given to calling waste heat as the main heat source, and the proportion of waste heat in the total heating energy is not less than 80%;

[0058] (b) When the waste heat supply is insufficient, other heat sources are supplemented in the following order and proportion:

[0059] ① Solar energy is enabled, and its supplement amount is 10% of the total required supplementary energy. At the same time, an air source heat pump is enabled, and its supplement amount reaches 90% of the total required supplementary energy;

[0060] ② When the solar heat is insufficient, the supplement amount of the air source heat pump reaches 100% of the total required supplementary energy;

[0061] By mandating that waste heat account for no less than 80%, a stable supply of basic energy is ensured, meeting the rigid requirement of energy continuity for oilfield production. When waste heat is insufficient, a two-level compensation mechanism is adopted, with solar energy prioritized and heat pumps providing a backup. When solar energy is available, it is responsible for 10% of the supplementary amount (both utilizing free energy and avoiding the risk of photovoltaic fluctuations), and the heat pump simultaneously takes on 90%, forming a reliable combination of "small photovoltaic regulation + large heat pump stabilization". When solar energy is insufficient, the fully controllable heat pump takes over 100%. This stepped compensation design not only ensures absolute energy stability in extreme situations (such as when there is no light at night), but also reduces heating costs by 10% when photovoltaic power is available during the day.

[0062] like Figure 1 As shown, the control unit includes an intelligent heat source collaborative scheduling module used in conjunction with the heating furnace to implement a dynamic energy allocation strategy;

[0063] This module is used to automatically trigger dynamic compensation when the heat source fluctuation exceeds ±15%. It is an emergency and dynamic adjustment mechanism, not a basic scheduling strategy under normal conditions. In the normal operation stage, a static priority strategy (such as a heat source priority control strategy) is adopted. In the scenario of unstable heat source or sudden increase in demand, the intelligent heat source collaborative scheduling module dynamically compensates and coordinates the loads of each heat source to ensure the continuity of heating and the optimization of energy efficiency. Specifically, the control unit monitors the waste heat supply in real time. When the fluctuation exceeds ±15%, solar thermal compensation and heat pump compensation are immediately started. Solar compensation quickly responds to sudden changes in light; heat pump compensation adapts to heat conduction delays, and calculates the energy stability index at the same time. When S<0.8, the energy storage buffer system (such as a molten salt tank or a backup battery pack) is automatically activated to temporarily fill the energy gap; the characteristics of solar energy (fast response) and heat pumps (cycle tuning) are matched respectively to solve the intermittent problem of renewable energy, compensate for the response speed, and control temperature fluctuations. In addition, the energy stability index S quantifies the system safety margin, and the energy storage buffer intervenes in advance to avoid downtime losses.

[0064] like Figures 1 to 3 As shown, the control unit has an error closed-loop adjustment logic, including the following steps:

[0065] S1: Collect the oil outlet temperature and target temperature in real time and calculate the temperature difference;

[0066] S2: Determine whether the error tolerance is exceeded, and if so, enter compensation control;

[0067] S3: Select one or more heat sources to participate in regulation according to the compensation intensity level;

[0068] S4: Recalculate the energy contribution rate and update the control coefficient every cycle;

[0069] S5: If the error does not return to zero for more than three cycles, the heat source call ratio will be locked to the current valid range and a fault prompt signal will be issued;

[0070] The control unit integrates a thermal energy anomaly response mechanism. When the output power of any heat source fluctuates by more than 30%, the re-injection pressure drops beyond the limit, or the heat exchange efficiency falls below 75%, the following response process is triggered: the redundant heat source is activated to temporarily replace the main heat source; the fault point feature code is recorded and the anomaly information is pushed to the remote control platform; if the anomaly is not resolved within three consecutive cycles, the air source heat pump will automatically switch to full-load operation mode and trigger an alarm signal.

[0071] When the control unit performs error closed-loop adjustment, the outlet oil temperature of the heating furnace is collected in real time. With target temperature , and then calculate the temperature difference ,when When the temperature is >1.5℃, compensation control is triggered, and the heat source is activated in stages according to the ΔT value (solar energy is enabled at 1.5-2.0℃, solar energy + heat pump is linked at 2.0-3.0℃, and all heat sources are coordinated at >3.0℃). The energy contribution rate is updated every 45 seconds. If ΔT is >1℃ for three consecutive cycles (135 seconds) and is not restored, the heat source call ratio is locked to the current valid range, and an audible and visual alarm is issued simultaneously. At the same time, when it is monitored that the power fluctuation of any heat source exceeds 30% of the rated value, the re-injection pressure suddenly increases by >20%, or the heat exchange efficiency is <75%, the air source heat pump is immediately activated to replace the faulty source. If the abnormality persists for three cycles and is not eliminated, an alarm signal is triggered.

[0072] like Figure 1 As shown, the water inlet of the oil storage and water reduction separator is provided with an inlet baffle for stabilizing the water flow and preventing the subsequent inflow of liquid from disturbing the liquid in the tank body. The oil storage and water reduction separator is automatically separated by gravity due to the different densities of water, oil and gas. The gas outlet is controlled by a pressure control valve to control the on-off of the gas pipeline. The crude oil with low water content and the separated high-temperature sewage pipeline are controlled by a liquid level control valve to control the size of the external flow. The reinjection well meets the requirements of low-pressure reinjection and is equipped with a filtering device and a degassing device for stabilizing the water flow and reducing the impurities and gas content of the reinjected sewage.

[0073] The crude oil produced with a higher water content enters the oil storage and water reduction separator through the liquid inlet pipe. It first passes through the inlet baffle to weaken the kinetic energy of the inlet liquid, preventing the high-speed liquid from directly impacting the liquid surface inside the tank, causing liquid level fluctuations or a decrease in separation efficiency. Then, it is naturally separated in layers under the action of gravity due to the density difference of the three phases of oil, water and gas inside the tank. The gas floats to the top due to the lowest density and is discharged from the gas outlet equipped with a pressure control valve. The control valve automatically adjusts the gas release frequency according to the pressure change in the tank, which prevents overpressure and avoids energy waste. The oil phase in the liquid part is located in the middle, and the crude oil with low water content is stably discharged from the middle outlet through the liquid level control valve, ensuring a constant flow of oil into the heating link; the separated water phase settles to the bottom due to its highest density. The oil is then transported to the subsequent intermediate heat exchanger and reinjection system through the bottom water outlet. Its flow rate is also dynamically adjusted by the liquid level control valve, making the overall external transmission process stable and preventing vacuum or backflow. At the same time, the reinjection well has low-pressure reinjection capability. It removes suspended particles and mechanical impurities through a built-in filter device, and releases residual gas through a degassing device to ensure the purity and continuity of the injected fluid, avoid impurities clogging the formation pores or gas containing to form air blockage, improve reinjection efficiency and ensure formation safety. The system achieves three-phase separation while also having pressure stability, precise liquid level control, flow balance regulation and reinjection water purification functions, thereby significantly improving the quality of oil-water separation, reducing the burden on subsequent equipment, and enhancing system safety and automatic operation capabilities.

[0074] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0075] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An oil recovery and water reduction combined with multi-source heating system, characterized in that: include: An oil storage and water reduction separator, wherein a liquid inlet is provided on one side of the top of the oil storage and water reduction separator, an exhaust port is provided in the middle of the top of the oil storage and water reduction separator, and a water outlet and an oil outlet are provided on one side of the bottom of the oil storage and water reduction separator. The oil storage and water reduction separator is used to receive produced fluid with high water content from the oil well, remove the water phase and gas phase through physical separation, and output the intermediate oil phase with lower water content to the heating furnace. The separated high-temperature water phase is transported to the multi-source heat pump unit for heat recovery; A waste heat recovery multi-source heat exchange unit, one side of which is connected to an oil production heating furnace, and the waste heat recovery multi-source heat exchange unit comprises: Multi-stage heat exchanger, the first stage recovers water phase sensible heat, the second stage absorbs solar thermal energy and air source heat energy; The water temperature control valve automatically adjusts the water flow according to the recharge well pressure to meet the following requirements: ， Among them, K=0.5−1.2 is the well pressure correction coefficient, Real-time data of the recharge well pressure sensor; A heating furnace is connected to the oil outlet of the oil storage and water reduction separator. A pumping pump is provided between the oil outlet and the heating furnace. The heating furnace can utilize the waste heat recovery multi-source heat exchange unit to provide heat to increase the temperature of the exported crude oil. The heating furnace includes a heat source priority control strategy: a. Prioritize waste heat as the main heat source, and the proportion of waste heat in the total heating energy should not be less than 80%; b. When the waste heat supply is insufficient, other heat sources should be added in the following order and proportion: ① Enable solar energy, which provides 10% of the total energy required, and enable air source heat pump, which provides 90% of the total energy required; ② When the solar energy is insufficient, the air source heat pump's supplementary amount reaches 100% of the total supplementary energy required; Recharge wells, which are transformed from abandoned wells in the oil field or are newly drilled wells. The layer where the sewage is recharged by the recharge wells is consistent with the oil-producing layer to prevent contamination of other layers; An intermediate heat exchanger, one side of which is connected to the waste heat recovery multi-source heat exchange unit, and the other side is connected to the water outlet of the oil storage and water reduction separator. A pumping pump body is provided between the intermediate heat exchanger and the waste heat recovery multi-source heat exchange unit. The intermediate heat exchanger is used to reduce the temperature of the high-temperature water separated by the water reduction separator and then re-inject it into the re-injection well. The waste heat recovery multi-source heat exchange unit uses the heat absorbed from the intermediate heat exchanger to heat the oil production heating furnace; A control unit is interconnected with the temperature sensors, flow meters, and pressure sensors in the waste heat recovery multi-source heat exchange unit, the heating furnace, and the oil storage and water reduction separator. The control unit is used to dynamically calculate the heat source priority and coordinate the scheduling of each heat source based on the real-time heat source output, oil temperature demand, and re-injection pressure, provide real-time feedback on heat exchange efficiency, and perform closed-loop control in combination with heat load response and energy efficiency evaluation.

2. The oil recovery and water reduction combined with multi-source heating system according to claim 1 is characterized in that: The first stage of the multi-stage heat exchanger is a double-helix counter-current tube, wherein the inner tube of the double-helix counter-current tube flows water phase, and the outer tube of the double-helix counter-current tube flows oil phase in the reverse direction.

3. The oil recovery and water reduction combined with multi-source heating system according to claim 1, characterized in that: The waste heat recovery multi-source heat exchange unit includes a combination structure of a plate heat exchanger and a shell and tube heat exchanger, and is provided with a bypass valve group, which can dynamically switch different heat exchange circuits according to the inlet and outlet water temperature difference and flow demand to optimize heat recovery efficiency.

4. The oil recovery and water reduction combined with multi-source heating system according to claim 1, characterized in that: The control unit includes an intelligent heat source collaborative scheduling module used in conjunction with the heating furnace to implement a dynamic energy allocation strategy.

5. The oil recovery and water reduction combined with multi-source heating system according to claim 4 is characterized in that: The control unit is provided with error closed-loop regulation logic, comprising the following steps: S1: Collect the oil outlet temperature and target temperature in real time and calculate the temperature difference; S2: Determine whether the error tolerance is exceeded, and if so, enter compensation control; S3: Select one or more heat sources to participate in regulation according to the compensation intensity level; S4: Recalculate the energy contribution rate and update the control coefficient every cycle; S5: If the error does not return to zero for more than three cycles, the heat source call ratio will be locked to the current valid range and a fault prompt signal will be issued.

6. The oil recovery and water reduction combined with multi-source heating system according to claim 5, characterized in that: The control unit integrates a thermal energy anomaly response mechanism. When the output power of any heat source fluctuates by more than 30%, the re-injection pressure rises beyond the limit, or the heat exchange efficiency falls below 75%, the following response process is triggered: a redundant heat source is activated to temporarily replace the primary heat source; a characteristic code of the fault point is recorded and the anomaly information is pushed to the remote control platform; If the abnormality is not resolved within three consecutive cycles, the system will automatically switch to the full-load operation mode of the air source heat pump and trigger an alarm signal.

7. The oil recovery and water reduction combined with multi-source heating system according to claim 1, characterized in that: The oil storage and water reduction separator has an inlet baffle at the water inlet to stabilize the water flow and prevent subsequent liquid inflow from disturbing the liquid in the tank. The oil storage and water reduction separator automatically separates water, oil and gas by gravity due to the different densities. The gas outlet is controlled by a pressure control valve to control the on-off of the gas pipeline. The low-water-content crude oil and separated high-temperature sewage pipelines are controlled by a liquid level control valve to control the size of the external transmission flow.

8. The oil recovery and water reduction combined with multi-source heating system according to claim 1, characterized in that: The reinjection well meets the requirements of low-pressure reinjection and is provided with a filtering device and a degassing device for stabilizing water flow and reducing impurities and gas content in the reinjected sewage.

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