Molten salt heating superheated steam generation system and control method thereof

Abstract

The embodiment of the invention provides a fused salt heating superheated steam generation system and a control method thereof, and belongs to the technical field of oilfield exploitation. The system comprises a water supply device, an evaporation device and a superheated steam generation device which are connected in sequence, a fused salt overflowing pipeline is arranged and used for providing a heat source for the hot steam generation device and the evaporation device; the water supply device is used for conveying the preheated low-temperature supply water to the evaporation device, so that the evaporation device converts the preheated low-temperature supply water into wet saturated steam; the superheated steam generating device is used for converting the wet saturated steam into superheated steam required by steam injection; and the control device is used for controlling the operation states of the water supply device, the evaporation device and the superheated steam generation device based on the steam injection requirement. According to the scheme, the problem that in the prior art, response to the dynamic steam injection demand is insufficient is effectively solved, the adaptability and operation efficiency of the system are remarkably improved, and the heavy oil recovery demand under the complex working condition is met.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield exploitation, and in particular to a molten salt heated superheated steam generating system and a molten salt heated superheated steam generating system control method. Background Art

[0002] In the current heavy oil production process in oil fields, steam injection technology is one of the key links to improve crude oil recovery. The steam injection system usually requires high-temperature, high-pressure superheated steam to meet the needs of oil wells. However, traditional steam injection systems mainly rely on gas boilers to generate steam, which not only leads to high energy consumption and large carbon emissions, but also limits the promotion and application of the system.

[0003] In order to solve these problems, existing technologies have gradually explored molten salt heating technology, using molten salt as a heat storage and heat transfer medium, using valley electricity or green electricity as the main energy source, to produce superheated steam. However, the existing molten salt steam injection scheme has shortcomings in the following key technologies: Insufficient dynamic adaptability of steam injection demand: Existing systems usually operate under fixed conditions and lack the ability to respond to the dynamic demand of steam injection wells (flow, temperature and pressure changes) in real time. As the production stage of the oil well changes, the steam injection demand shows nonlinear and dynamic fluctuation characteristics, and the fixed parameter operation mode easily leads to steam waste or insufficient supply, reducing the efficiency of steam injection.

[0004] Insufficient control accuracy of the mixer: During the mixing process of superheated steam and saturated water, the existing technology lacks a high-precision, real-time control solution, and cannot ensure that the temperature and flow of the mixed steam always meet the steam injection requirements. This lack of control may lead to unstable superheat or flow deviation of the mixed steam, which directly affects the downhole oil production effect.

[0005] In summary, the existing technology cannot effectively respond to the dynamic changes in steam injection demand, and the accuracy of the mixing process also has technical bottlenecks. There is an urgent need for a dynamic control method that can adapt to changes in steam injection demand in real time, optimize the operating parameters of the mixer, and ensure the stability of the mixed steam and the steam injection efficiency. Summary of the invention

[0006] The purpose of the embodiments of the present invention is to provide a molten salt heated superheated steam generating system and a control method thereof, so as to at least solve the problem that the prior art cannot effectively cope with the dynamic changes of steam injection demand and the insufficient accuracy of the mixing process.

[0007] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a molten salt heated superheated steam generation system, the system comprising: a water supply device, an evaporation device and a superheated steam generation device connected in sequence; a molten salt flow pipe is provided from the superheated steam generation device to the evaporation device, for providing a heat source to the hot steam generation device and the evaporation device; the water supply device is used to preheat the low-temperature supply water and transmit the preheated low-temperature supply water to the evaporation device, so that the evaporation device converts the preheated low-temperature supply water into wet saturated steam; the superheated steam generation device is used to convert the wet saturated steam into superheated steam for steam injection demand; a control device is used to perform operating state control of the water supply device, the evaporation device and the superheated steam generation device based on the steam injection demand.

[0008] Optionally, the water supply device includes: an oilfield produced water supply pipeline, used to input oilfield produced water as low-temperature supply water for the water supply device; a preheating module, connected to the oilfield produced water supply pipeline, used to preheat the low-temperature supply water; the preheating module is connected to the evaporation device through a pipeline, used to transmit the preheated low-temperature supply water to the evaporation device.

[0009] Optionally, the preheating module includes: a wet saturated steam preheating module, a solar energy preheating module and a geothermal energy preheating module, which are combined to preheat the low-temperature supply water; the wet saturated steam of the wet saturated steam preheating module is separated from the wet saturated steam output by the evaporation device, and is merged into the wet saturated steam preheating module based on a first wet steam pipeline; the other part of the wet saturated steam output by the evaporation device is merged into the evaporation device based on a second wet steam pipeline.

[0010] Optionally, the solar energy preheating module includes: a concentrating solar collector, which is arranged between the wet saturated steam preheating module and the oilfield produced water supply pipeline, and is used to perform the first stage preheating of the low-temperature supply water; the geothermal energy preheating module includes: a geothermal heat exchanger, which is arranged in parallel with the concentrating solar collector, and is combined with the concentrating solar collector to perform the first stage preheating of the low-temperature supply water.

[0011] Optionally, the geothermal heat exchanger is provided with a three-way valve; the water inlet of the three-way valve is used to collect the heating medium of the geothermal heat exchanger; the water outlet of the three-way valve leads to the preheating module and the molten salt heating module respectively; the valve opening and closing degree of the three-way valve leading to the preheating module and the molten salt heating module respectively is controlled based on the control module.

[0012] Optionally, the control module is configured to: construct a corresponding LSTM model based on historical steam injection data, real-time steam demand and oil well operating parameters to predict the steam injection demand at a predetermined time in the future; determine the low-temperature supply water preheating demand based on the steam injection demand and the heat exchange efficiency of the evaporator; determine the heat exchange power to be supplemented of the geothermal energy preheating module that performs low-temperature supply water preheating based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module; generate a control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module based on the heat exchange power to be supplemented of the geothermal energy preheating module, and generate a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module based on the remaining heat exchange power of the geothermal energy preheating module.

[0013] Optionally, the heat exchange power to be supplemented of the geothermal energy preheating module that performs low-temperature water supply preheating is determined based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module, including: based on a collaborative game theory algorithm, the preheating module and the molten salt heating module are regarded as game parties to maximize the steam injection demand satisfaction rate and the molten salt heat storage efficiency to construct a corresponding objective function; based on the Lagrangian relaxation method, iteratively solve the objective function to obtain the optimal heat exchange power to be supplemented of the geothermal energy preheating module that performs low-temperature water supply preheating.

[0014] Optionally, the objective function is expressed as:

[0015] in, and Preset weighting factors representing the importance of produced water preheating demand and molten salt thermal storage demand, respectively; geothermal heat supply for preheating of produced water; Total preheating requirements for produced water; to supply geothermal heat allocated for molten salt heating; Target demand for molten salt heating.

[0016] Optionally, the evaporation device includes multiple heat exchangers; each heat exchanger is connected in series through a pipeline, the water inlet of the first heat exchanger is connected to the water outlet of the water supply device, and the water outlet of the last heat exchanger is the output port of the wet saturated steam; the molten salt flow pipe flows from the last heat exchanger to the first heat exchanger, and flows back from the first heat exchanger to the molten salt heating module.

[0017] Optionally, the superheated steam generating device includes: a steam-water separator, which is used to separate the incoming wet saturated steam into steam and water to obtain dry steam and saturated water respectively; the dry steam and saturated water output by the steam-water separator are connected to the superheater and the mixer through the dry steam pipe and the separation water pipe respectively; the superheater performs heat exchange with the molten salt flow pipe to convert the dry steam into superheated steam.

[0018] Optionally, the superheater is connected to another inlet of the mixer through a first superheated steam pipe to merge the superheated steam into the mixer; the mixer is used to mix the superheated steam and saturated water based on the gas injection demand to obtain superheated steam that meets the steam injection demand, and output the superheated steam to the steam injection well through a second superheated steam pipe.

[0019] Optionally, the control module is configured to: construct a corresponding heat balance model and flow balance model based on state information of superheated steam and saturated water entering the mixer; determine the mixing ratio of superheated steam and saturated water based on the heat balance model and the flow balance model; and regulate the valve opening of the mixer in real time according to the mixing ratio.

[0020] Optionally, the heat balance model is expressed as:

[0021] The flow balance model is expressed as:

[0022] in, , and They are the mass flow rate of mixed steam, the mass flow rate of superheated steam and the mass flow rate of saturated water respectively; , and They are the specific enthalpy of mixed steam, the specific enthalpy of superheated steam and the specific enthalpy of saturated water respectively.

[0023] Optionally, the mixing ratio of superheated steam and saturated water is determined based on a heat balance model and a flow balance model, including: performing a joint solution based on the heat balance model and the flow balance model to obtain a flow ratio of superheated steam to saturated water to determine the mixing ratio of superheated steam and saturated water.

[0024] Optionally, after adjusting the valve opening of the mixer in real time according to the mixing ratio, the control device is further configured to: collect the state parameters of the superheated steam required for steam injection in real time, and identify the deviation between the state parameters of the superheated steam and the target superheated steam; and execute a PID control algorithm based on the deviation to correct the valve opening of the mixing device, so as to keep the deviation between the state parameters of the actual superheated steam and the state parameters of the target superheated steam within a preset difference threshold range.

[0025] A second aspect of the present invention provides a molten salt heated superheated steam generating system control method, which is applied to the molten salt heated superheated steam generating system according to any one of claims 1 to 15, and the method comprises: collecting real-time steam injection demand information, and based on the steam injection demand information, respectively performing target operating state simulations of a water supply device, an evaporation device and a superheated steam generating device; based on deviation values ​​between the real-time operating states of the water supply device, the evaporation device and the superheated steam generating device and the corresponding target operating states, respectively generating control schemes for the water supply device, the evaporation device and the superheated steam generating device; and executing the control schemes to respectively achieve state adjustments of the water supply device, the evaporation device and the superheated steam generating device.

[0026] Optionally, the water supply device includes: an oilfield produced water supply pipeline, used to input oilfield produced water as low-temperature supply water for the water supply device; a preheating module, connected to the oilfield produced water supply pipeline, used to preheat the low-temperature supply water; the preheating module is connected to the evaporation device through a pipeline, used to transmit the preheated low-temperature supply water to the evaporation device.

[0027] Optionally, the preheating module includes: a wet saturated steam preheating module, a solar energy preheating module and a geothermal energy preheating module, which are combined to perform preheating on the low-temperature supply water; the wet saturated steam of the wet saturated steam preheating module is obtained by separating the wet saturated steam output by the evaporation device, and is fed into the wet saturated steam preheating module based on a first wet steam pipeline; another part of the wet saturated steam output by the evaporation device is fed into the evaporation device based on a second wet steam pipeline; the solar energy preheating module includes: a concentrating solar collector, which is arranged between the wet saturated steam preheating module and the oilfield produced water Between the water supply pipes, it is used to perform the first stage preheating of the low-temperature supply water; the geothermal energy preheating module includes: a geothermal heat exchanger, which is arranged in parallel with the concentrating solar collector, and combined with the concentrating solar collector to perform the first stage preheating of the low-temperature supply water; the geothermal heat exchanger is provided with a three-way valve; the water inlet of the three-way valve is used to merge the heating medium of the geothermal heat exchanger; the water outlet of the three-way valve leads to the preheating module and the molten salt heating module respectively; the valve opening and closing degree of the three-way valve leading to the preheating module and the molten salt heating module respectively is controlled based on the control module.

[0028] Optionally, the generation rule of the control scheme of the preheating module is as follows: based on historical steam injection data, real-time steam demand and oil well operating parameters, a corresponding LSTM model is constructed to predict the steam injection demand at a predetermined time in the future; based on the steam injection demand and the heat exchange efficiency of the evaporator, the low-temperature supply water preheating demand is determined; based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module, the heat exchange power to be supplemented of the geothermal energy preheating module that performs the preheating of the low-temperature supply water is determined; based on the heat exchange power to be supplemented of the geothermal energy preheating module, a control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module is generated, and based on the remaining heat exchange power of the geothermal energy preheating module, a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module is generated as the control scheme of the preheating module.

[0029] On the other hand, the present invention provides a computer-readable storage medium having instructions stored thereon, which, when executed on a computer, enables the computer to execute the above-mentioned molten salt heated superheated steam generation system control method.

[0030] Through the above technical scheme, the scheme of the present invention constructs an efficient and flexible steam injection steam generation system by sequentially connecting a water supply device, an evaporation device and a superheated steam generation device, and combining a molten salt flow pipe to provide a heat source. The water supply device preheats the low-temperature supply water, improves the heat exchange efficiency, and reduces the heat load of the evaporation device, thereby realizing the efficient utilization of water resources and thermal energy; the evaporation device converts the preheated supply water into wet saturated steam, providing a stable basis for the subsequent generation of superheated steam; the superheated steam generation device generates superheated steam that meets the steam injection demand by further heating the wet saturated steam. Based on the real-time steam injection demand, the control device dynamically adjusts the operating status of each device to achieve the optimization of the entire process from water supply preheating to steam superheating, and ensure the accuracy and stability of the output steam parameters. The overall solution effectively solves the problem of insufficient response to dynamic steam injection demand in the prior art, significantly improves the adaptability and operating efficiency of the system, and meets the needs of heavy oil production under complex working conditions.

[0031] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 It is a system structure diagram of a molten salt heating superheated steam generation system provided by one embodiment of the present invention; Figure 2It is a schematic diagram of the specific structure of a molten salt heating superheated steam generating system provided by one embodiment of the present invention; Figure 3 It is a flow chart of the steps of a method for controlling a molten salt heated superheated steam generation system provided by one embodiment of the present invention.

[0033] Description of Reference Numerals 1-preheating water pipeline; 2-evaporator; 3-extraction steam pipeline; 4-first wet steam pipeline; 5-second wet steam pipeline; 6-second hot salt pipeline; 7-steam-water separator; 8-separation water pipeline; 9-dry steam pipeline; 10-superheater; 11-first superheated steam pipeline; 12-mixer; 13-second superheated steam pipeline; 14-first hot salt pipeline; 15-cold salt pipeline; 16-preheater; 17-oilfield produced water supply pipeline; 18-condensate pipeline. DETAILED DESCRIPTION

[0034] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0035] Figure 1 1 is a system structure diagram of a molten salt heating superheated steam generation system provided by one embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides a molten salt heated superheated steam generating system, the system comprising: a water supply device, an evaporation device and a superheated steam generating device connected in sequence; a molten salt flow pipe is provided from the superheated steam generating device to the evaporation device, for providing a heat source to the hot steam generating device and the evaporation device; the water supply device is used to preheat the low-temperature supply water, and transmit the preheated low-temperature supply water to the evaporation device, so that the evaporation device converts the preheated low-temperature supply water into wet saturated steam; the superheated steam generating device is used to convert the wet saturated steam into superheated steam for steam injection demand; a control device is used to perform operating state control of the water supply device, the evaporation device and the superheated steam generating device based on the steam injection demand.

[0036] Preferably, the water supply device includes: an oilfield produced water supply pipeline, which is used to input oilfield produced water as low-temperature supply water for the water supply device; a preheating module, which is connected to the oilfield produced water supply pipeline and is used to preheat the low-temperature supply water; the preheating module is connected to the evaporation device through a pipeline, and is used to transmit the preheated low-temperature supply water to the evaporation device.

[0037] In the embodiment of the present invention, the oilfield produced water supply pipeline is one of the core components of the water supply device, which is used to stably input the oilfield produced water into the system to provide sufficient water source for steam production. Since the oilfield produced water usually has the characteristics of low initial temperature and high silicon content, it is easy to cause scaling of the heat exchanger and reduce the system efficiency if it is directly used in the evaporation process, so it needs to be pre-treated.

[0038] The preheating module is connected to the oilfield produced water supply pipeline and uses efficient heat exchange technology to preheat the low-temperature supply water. During the preheating process, the waste heat of the molten salt system, the extraction heat of wet saturated steam and other heat sources can be used to increase the water supply temperature from the initial 40-70°C to 230-250°C, effectively reducing the heat load of the evaporation device and reducing the risk of scaling in the evaporator. The preheated low-temperature supply water is transmitted to the evaporation device through a pipeline, further improving the thermal efficiency of the evaporation process and the system stability.

[0039] Based on the scheme of the present invention, the problems of evaporator scaling and low thermal efficiency caused by poor water quality and excessive temperature difference in the traditional system are solved by efficiently preheating and stably transporting the produced water from the oil field; on the other hand, by optimizing the matching of water supply temperature and evaporation conditions, the overall energy utilization rate of the system is significantly improved. In addition, the introduction of the preheating module provides the possibility of integrating multiple heat sources into the system. For example, the use of external heat sources such as solar energy and geothermal energy can further improve the preheating efficiency, creating conditions for the application of green energy. Overall, the water supply device provides ideal water supply conditions for the subsequent evaporation device and superheated steam generation device, ensuring the efficient and stable operation of the system and meeting the dynamic steam injection requirements.

[0040] Preferably, the preheating module includes: a wet saturated steam preheating module, a solar energy preheating module and a geothermal energy preheating module, which are combined to perform preheating on the low-temperature supply water; the wet saturated steam of the wet saturated steam preheating module is separated from the wet saturated steam output by the evaporation device, and is merged into the wet saturated steam preheating module based on the first wet steam pipeline; the other part of the wet saturated steam output by the evaporation device is merged into the evaporation device based on the second wet steam pipeline.

[0041] In the embodiment of the present invention, the preheating module is composed of a wet saturated steam preheating module, a solar preheating module and a geothermal preheating module, which work together to efficiently preheat the low-temperature supply water. This modular preheating structure not only improves the thermal energy utilization rate of the system, but also provides technical support for the flexible integration of multiple heat sources.

[0042] Among them, the wet saturated steam preheating module realizes efficient heat recovery by utilizing the wet saturated steam output by the evaporation device. After the wet saturated steam is separated, a part of it is introduced into the wet saturated steam preheating module through the first wet steam pipeline to preheat the low-temperature supply water. In this way, not only the sensible heat and latent heat of the wet saturated steam are recovered, but also the heat waste caused by direct discharge is avoided, and the overall energy consumption of the evaporation device is reduced. The other part of the wet saturated steam is transported back to the evaporation device through the second wet steam pipeline to adjust the stability of the evaporation device and further optimize the heat energy distribution.

[0043] As one of the ways to utilize clean energy, the solar preheating module converts the collected solar heat into a heat source for low-temperature water supply through a high-efficiency solar collector. This module not only reduces dependence on traditional energy, but also utilizes the difference in grid load during the day and night, coordinates the system with green electricity, and improves energy utilization efficiency.

[0044] The geothermal energy preheating module extracts geothermal resources through geothermal heat exchangers to preliminarily heat the low-temperature supply water. This design of utilizing low-temperature geothermal resources fully utilizes the advantages of geothermal resources in primary heat energy supplementation, reduces the load of the molten salt system in the preheating stage, and provides stable water supply conditions for subsequent evaporation devices. In the process of heavy oil steam injection development, drilling is an indispensable operation, and the development of geothermal resources also requires drilling. Combining steam injection drilling with geothermal development drilling can share drilling resources and reduce overall construction costs. This integrated utilization not only avoids the waste caused by repeated drilling, but also fully utilizes the value of drilling equipment. Oilfield blocks are usually located in geologically active areas, which are often accompanied by rich geothermal resources. Steam injection development itself requires deep drilling, and geothermal fluids (such as geothermal hot water or geothermal steam) can be directly obtained through drilling operations. This natural way to obtain geothermal resources provides a low-cost and stable heat source for the preheating and heating process of the steam injection system.

[0045] Preferably, the solar energy preheating module includes: a concentrating solar collector, which is arranged between the wet saturated steam preheating module and the oilfield produced water supply pipeline, and is used to perform the first stage preheating of the low-temperature supply water; the geothermal energy preheating module includes: a geothermal heat exchanger, which is arranged in parallel with the concentrating solar collector, and is combined with the concentrating solar collector to perform the first stage preheating of the low-temperature supply water.

[0046] In an embodiment of the present invention, the solar preheating module includes a concentrating solar collector, which is mainly arranged between the wet saturated steam preheating module and the oilfield produced water supply pipeline, and is used to perform the first stage preheating of the low-temperature supply water. The concentrating solar collector captures solar heat and converts it into thermal energy through efficient concentration and heat absorption technology, providing a preliminary temperature increase for the supply water. The collector can automatically adjust the focusing angle according to the intensity of sunlight, maximize the heat collection efficiency, and increase the initial temperature of the supply water from the ambient temperature to 50-90°C, thereby reducing the heat load for the subsequent wet saturated steam preheating module. In addition, the module can combine the day and night grid load fluctuations, and through the coordinated operation of valley electricity and green electricity, provide stable and low-cost clean energy preheating for the water supply system.

[0047] Furthermore, the geothermal energy preheating module includes a geothermal heat exchanger, which is arranged in parallel with a concentrating solar collector, and the combination completes the first stage preheating of the low-temperature supply water. The geothermal heat exchanger is directly connected to the geothermal well, and transfers the heat of the geothermal fluid to the supply water through a high-efficiency heat exchanger. This module makes full use of the stable heat supply capacity of geothermal resources, is not restricted by weather and time, and provides reliable heat input for low-temperature supply water. During the preheating process, the geothermal heat exchanger and the solar collector operate in coordination, each taking on the main preheating tasks in different time periods. For example, solar energy is the main heat source during the day, and geothermal heat is used as an auxiliary heat source; at night and on cloudy days, heat is completely provided by geothermal heat to ensure the continuity and stability of the entire water supply system.

[0048] Furthermore, by arranging the concentrated solar collector and the geothermal heat exchanger in parallel and combining them to complete the first stage of preheating, this solution achieves efficient coordination of multiple heat sources. The combined use of solar energy and geothermal energy not only improves the energy utilization efficiency of the preheating process, but also reduces the cost and carbon emissions caused by the consumption of traditional energy (such as electricity and gas). At the same time, this modular preheating system is also highly flexible and can adjust the work priority of each module according to seasonal and regional resource differences.

[0049] Preferably, the geothermal heat exchanger is provided with a three-way valve; the water inlet of the three-way valve is used to introduce the heating medium of the geothermal heat exchanger; the water outlet of the three-way valve leads to the preheating module and the molten salt heating module respectively; the valve opening and closing degree of the three-way valve leading to the preheating module and the molten salt heating module respectively is controlled based on the control module.

[0050] In the embodiment of the present invention, the water inlet of the three-way valve is connected to the heating medium of the geothermal heat exchanger, which mainly flows into the hot fluid (such as geothermal hot water or geothermal steam) from the geothermal well. Through the design of the three-way valve, the heat output by the geothermal heat exchanger can be transmitted to the preheating module and the molten salt heating module respectively, realizing the efficient utilization and flexible allocation of geothermal resources.

[0051] The outlet of the three-way valve is connected to the preheating module and the molten salt heating module respectively. The opening and closing degree of the valves at each outlet is dynamically adjusted according to the system operation requirements, thereby adjusting the geothermal heat flow transmitted to different modules. The preheating module is mainly used to heat the produced water of the oil field to provide stable wet saturated steam for the subsequent evaporation device; the molten salt heating module uses geothermal heat to supplement the molten salt heat storage system and provide a continuous heat source for the production of superheated steam. The three-way valve is connected to the control module to achieve real-time regulation: the control module dynamically adjusts the opening and closing ratio of the three-way valve according to the steam injection demand, the current system operation status and the heating capacity of the geothermal fluid to ensure the optimal solution for geothermal heat distribution.

[0052] Preferably, the control module is configured to: construct a corresponding LSTM model based on historical steam injection data, real-time steam demand and oil well operating parameters to predict the steam injection demand at a predetermined time in the future; determine the low-temperature supply water preheating demand based on the steam injection demand and the heat exchange efficiency of the evaporator; determine the heat exchange power to be supplemented of the geothermal energy preheating module that performs low-temperature supply water preheating based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module; generate a control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module based on the heat exchange power to be supplemented of the geothermal energy preheating module, and generate a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module based on the remaining heat exchange power of the geothermal energy preheating module.

[0053] Furthermore, the heat exchange power to be supplemented of the geothermal energy preheating module that performs low-temperature water supply preheating is determined based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module, including: based on a collaborative game theory algorithm, the preheating module and the molten salt heating module are regarded as game parties to maximize the steam injection demand satisfaction rate and the molten salt heat storage efficiency to construct a corresponding objective function; based on the Lagrangian relaxation method, the objective function is iteratively solved to obtain the optimal heat exchange power to be supplemented of the geothermal energy preheating module that performs low-temperature water supply preheating.

[0054] In the embodiment of the present invention, the heat distribution between the geothermal energy preheating module and the molten salt heating module is dynamically controlled through prediction algorithms and optimization strategies to ensure efficient satisfaction of steam injection demand and economical operation of the overall system. The core functions of the control module mainly include prediction of steam injection demand, determination of low-temperature water preheating demand, calculation of the heat exchange power to be supplemented by the geothermal energy preheating module, and generation of a valve control scheme for the three-way valve based on the heat exchange power distribution. Specifically, it includes the following contents: 1) Steam injection demand prediction: The control module first builds an LSTM (Long Short-Term Memory Network) model based on historical steam injection data, real-time steam demand and oil well operating parameters to predict the steam injection demand at a specific moment in the future. The LSTM model can effectively capture the dynamic changes in steam injection demand through deep learning of historical data and real-time parameters. For example, when the oil well enters different recovery stages or the ambient temperature changes, the steam injection demand may fluctuate nonlinearly, and the LSTM model can give accurate prediction results in advance based on these changes. This prediction function provides a scientific basis for subsequent preheating demand and geothermal energy allocation, ensuring the foresight and responsiveness of system operation.

[0055] 2) Determination of the preheating requirement of the low-temperature feed water: Based on the prediction results of the steam injection demand and the heat exchange efficiency of the evaporator, the control module calculates the preheating requirement of the low-temperature feed water. The heat exchange efficiency of the evaporator directly affects the ability to generate wet saturated steam, and the preheating degree of the low-temperature feed water determines the heat load of the evaporator. By comprehensively considering these factors, the control module can accurately determine the target temperature that the low-temperature feed water needs to reach to meet the steam injection demand while reducing the risk of scaling in the evaporator and improving the overall heat exchange efficiency.

[0056] 3) Calculation of the heat exchange power to be supplemented by the geothermal preheating module: The control module further combines the real-time heat exchange power of the wet saturated steam preheating module and the solar preheating module to dynamically calculate the heat exchange power to be supplemented by the geothermal preheating module. The wet saturated steam preheating module uses the wet saturated steam from the evaporator for heat recovery, and the solar preheating module provides a clean heat source through efficient concentration technology. However, the heat supply of these two parts is volatile, especially the solar module is greatly affected by weather and day and night conditions. Therefore, the control module needs to monitor the heat exchange power of these two modules in real time, and calculate the part that cannot be met as the heat exchange power to be supplemented by the geothermal preheating module.

[0057] In order to optimize this allocation process, the control module introduces a collaborative game theory algorithm, regards the preheating module and the molten salt heating module as game parties, and constructs the corresponding objective function with the goal of maximizing the steam injection demand satisfaction rate and the molten salt heat storage efficiency. The introduction of collaborative game theory enables the system to dynamically balance the resource allocation of the two, which not only ensures the sufficient preheating of the low-temperature supply water, but also reserves enough heat for the molten salt system for the subsequent production of superheated steam.

[0058] 4) Optimization of heat exchange power allocation: The control module performs iterative solution to the objective function through the Lagrangian relaxation method to obtain the optimal heat exchange power to be supplemented for the geothermal preheating module. The Lagrangian relaxation method is a mathematical tool suitable for solving complex constrained optimization problems. By introducing relaxation variables, the original objective function is decomposed into easy-to-solve sub-problems, thereby approaching the global optimal solution in multiple rounds of iterations. This method can accurately calculate the supplementary power required for the geothermal preheating module and ensure the economy and effectiveness of resource allocation.

[0059] 5) Generation of three-way valve control scheme: Based on the heat exchange power to be supplemented by the geothermal energy preheating module, the control module generates a control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module. At the same time, according to the remaining heat exchange power of the geothermal energy preheating module, a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module is generated. The dynamic regulation of the three-way valve is performed in real time by the control module to ensure the reasonable allocation of geothermal resources among different modules. The preheating module gives priority to meeting the preheating requirements of the low-temperature supply water, while the molten salt heating module uses the remaining geothermal energy for heat storage to provide a supplementary heat source for the production of superheated steam.

[0060] Based on the scheme of the present invention, through the prediction function of the LSTM model, the control module can capture the dynamic changes of steam injection demand in advance, making the system operation more intelligent and precise, and effectively reducing heat waste and insufficient heating. The introduction of the collaborative game theory algorithm ensures the optimal allocation of geothermal resources between the preheating module and the molten salt heating module, which not only meets the current steam injection demand, but also provides reserve heat for subsequent steam production. The optimization solution of the Lagrangian relaxation method makes the heat exchange power distribution more efficient, thereby reducing the excessive consumption of geothermal resources and other energy sources and reducing the operating cost of the system. Through the dynamic regulation of the three-way valve, the control module can adapt to the fluctuations of steam injection demand and heat exchange module performance in real time, ensuring the stable operation of the system under various working conditions. Combined with the clean heat source of wet saturated steam and solar preheating module, the control module minimizes the dependence on traditional energy and improves the environmental friendliness of the system.

[0061] Specifically, the objective function is expressed as:

[0062] in, and Preset weighting factors representing the importance of produced water preheating demand and molten salt thermal storage demand, respectively; geothermal heat supply for preheating of produced water; Total preheating requirements for produced water; to supply geothermal heat allocated for molten salt heating; Target demand for molten salt heating.

[0063] Preferably, the evaporation device includes multiple heat exchangers; each heat exchanger is connected in series through a pipeline, the water inlet of the first heat exchanger is connected to the water outlet of the water supply device, and the water outlet of the last heat exchanger is the output port of the wet saturated steam; the molten salt flow pipe flows from the last heat exchanger to the first heat exchanger, and flows back from the first heat exchanger to the molten salt heating module.

[0064] In an embodiment of the present invention, the evaporation device is composed of a plurality of heat exchangers, each of which is connected in series through a pipeline to form an efficient step-by-step heating and evaporation system. The water inlet of the first heat exchanger is connected to the water outlet of the water supply device, which provides preheated low-temperature water supply, and starts primary heating after entering the first heat exchanger. Under the serial action of multiple heat exchangers, the water temperature is gradually increased, gradually approaching the saturated state, until the last heat exchanger heats the water supply to the wet saturated steam state, completing the evaporation process. The final wet saturated steam is transported to the subsequent steam-water separator or superheater through the water outlet to meet the needs of the steam injection system. In order to ensure the heat exchange efficiency and the full utilization of the molten salt heat, the evaporation device is equipped with a molten salt flow pipe. The pipe flows from the last heat exchanger to the first heat exchanger, and forms an efficient heat gradient in the evaporation device through the reverse heat transfer mechanism. The molten salt starts to cool down from the last stage of the heat exchanger, and gradually transfers the heat to the previous stages of the heat exchanger to ensure the maximum utilization of the heat energy in the system. Finally, the molten salt flows back from the first heat exchanger to the molten salt heating module and is reheated and recycled.

[0065] Preferably, the superheated steam generating device includes: a steam-water separator for separating the incoming wet saturated steam into steam and water to obtain dry steam and saturated water respectively; the dry steam and saturated water output by the steam-water separator are connected to the superheater and the mixer through the dry steam pipeline and the separation water pipeline respectively; the superheater performs heat exchange with the molten salt flow pipeline to convert the dry steam into superheated steam.

[0066] Furthermore, the superheater is connected to another inlet of the mixer through a first superheated steam pipe to merge the superheated steam into the mixer; the mixer is used to mix the superheated steam and saturated water based on the gas injection demand to obtain superheated steam that meets the steam injection demand, and output the superheated steam to the steam injection well through a second superheated steam pipe.

[0067] In an embodiment of the present invention, the superheated steam generating device realizes the precise conversion of wet saturated steam to superheated steam that meets the steam injection demand through the combination of a steam-water separator, a superheater and a mixer, thereby providing efficient and stable steam output for the steam injection well. The steam-water separator is one of the core components of the entire device, which is responsible for steam-water separation of wet saturated steam. During the separation process, wet saturated steam is separated into dry steam and saturated water according to the density difference between steam and liquid water. This process not only improves the quality of steam, but also provides a suitable basic working fluid for subsequent superheating and mixing processes. The dry steam output by the steam-water separator is transmitted to the superheater through the dry steam pipeline for further heating, and the separated saturated water is transported to the mixer through the separation water pipeline to be mixed with the superheated steam.

[0068] Furthermore, the superheater heats the dry steam to a high superheat state by heat exchange with the molten salt flow pipe, thereby generating high-quality superheated steam. The molten salt flow pipe is used as a heat source, and the stable heat supply of high-temperature molten salt is used to achieve efficient heating of dry steam. This design not only ensures that the temperature of the superheated steam meets the requirements of the steam injection well, but also effectively reduces energy loss. The superheated steam output by the superheater is transported to the mixer through the first superheated steam pipeline and mixed with the saturated water transported by the separation water pipeline according to the required proportion. The function of the mixer is to accurately mix the superheated steam with high superheat and saturated water according to the real-time steam injection demand to generate the target superheated steam that meets the downhole conditions. By adjusting the mixing ratio of superheated steam and saturated water, the temperature and pressure of the mixed steam can be accurately controlled to ensure the efficiency and stability of the steam injection process. The generated target superheated steam is transported to the steam injection well through the second superheated steam pipeline to provide the necessary thermal energy support for heavy oil production.

[0069] Preferably, the control module is configured to: construct a corresponding heat balance model and flow balance model based on the state information of the superheated steam and saturated water flowing into the mixer; determine the mixing ratio of the superheated steam and the saturated water based on the heat balance model and the flow balance model; and regulate the valve opening of the mixer in real time according to the mixing ratio.

[0070] Specifically, the thermal balance model is expressed as:

[0071] The flow balance model is expressed as:

[0072] in, , and They are the mass flow rate of mixed steam, the mass flow rate of superheated steam and the mass flow rate of saturated water respectively; , and They are the specific enthalpy of mixed steam, the specific enthalpy of superheated steam and the specific enthalpy of saturated water respectively.

[0073] Furthermore, the mixing ratio of superheated steam and saturated water is determined based on the heat balance model and the flow balance model, including: performing a joint solution based on the heat balance model and the flow balance model to obtain the flow ratio of superheated steam and saturated water to determine the mixing ratio of superheated steam and saturated water.

[0074] In an embodiment of the present invention, the control module is configured to construct a corresponding heat balance model and flow balance model based on the real-time status information of the superheated steam and saturated water introduced by the blender, so as to realize dynamic regulation of the mixing ratio of superheated steam and saturated water. The heat balance model is used to calculate the energy distribution of the mixed steam to ensure that the temperature and pressure of the output steam meet the steam injection requirements, while the flow balance model is used to determine the mass flow ratio of superheated steam and saturated water during the mixing process to ensure the accuracy of the total steam flow. Based on these two models, the control module can adjust the opening and closing degree of the valve in the blender in real time, so as to dynamically realize the optimal mixing of superheated steam and saturated water.

[0075] In the heat balance model, the system calculates the energy composition of the mixed steam by monitoring the enthalpy (i.e., the heat per unit mass) of the mixed steam, superheated steam, and saturated water. The goal of the heat balance model is to ensure that the enthalpy of the mixed steam matches the steam injection demand, thereby meeting the steam temperature requirements of the oil well. This model fully considers the initial state of the superheated steam and saturated water (such as temperature, pressure, enthalpy, etc.), and dynamically updates its parameters to adapt to the real-time changing steam injection demand.

[0076] The flow balance model is used to ensure the conservation of materials in the system. It further determines the flow ratio of superheated steam and saturated water by accurately calculating the total flow of mixed steam and combining it with the heat balance model. The core of this model is to ensure that the total flow of mixed steam is consistent with the steam injection demand, while avoiding excessive use of superheated steam or saturated water and optimizing resource utilization efficiency.

[0077] Based on the heat balance model and flow balance model, the control module can dynamically determine the mixing ratio of superheated steam and saturated water through joint solution. Specifically, the control module monitors the state parameters of superheated steam and saturated water input by the mixer in real time, and calculates the required mixing ratio based on the steam injection demand. Subsequently, the opening and closing degree of the valves of each channel in the mixer is adjusted according to the calculation results to ensure that the temperature, pressure and flow of the mixed steam are consistent with the target value.

[0078] Preferably, after adjusting the valve opening of the mixer in real time according to the mixing ratio, the control device is further configured to: collect the state parameters of the superheated steam required for steam injection in real time, and identify the deviation value between the state parameters of the superheated steam and the target superheated steam; and execute the PID control algorithm based on the deviation value to correct the valve opening of the mixing device, so as to keep the deviation value between the state parameters of the actual superheated steam and the state parameters of the target superheated steam within a preset difference threshold range.

[0079] In the embodiment of the present invention, after completing the preliminary control of the valve opening based on the mixing ratio, the control device further optimizes the control process by real-time monitoring of the superheated steam state parameters of the steam injection demand and identifying the deviation between the actual superheated steam and the target superheated steam state parameters. To achieve this purpose, the control device introduces a PID (proportional-integral-differential) control algorithm to dynamically correct the valve opening of the mixer to ensure that the actual output superheated steam state is always consistent with the target requirement.

[0080] Specifically, the control device first collects the key state parameters of the superheated steam output during the steam injection process, such as temperature, pressure and flow, in real time through the sensor network. These parameters directly affect the thermal efficiency and oil recovery effect of downhole steam injection, so their accuracy is crucial. At the same time, the control device presets the parameter range of the target superheated steam and defines these parameter values ​​according to the downhole demand and the real-time adjusted steam injection target. Subsequently, the control device calculates the deviation between the actual parameter and the target parameter to identify whether there are problems such as insufficient temperature, pressure deviation or unstable flow. Once it is detected that the deviation value exceeds the preset threshold range, the control device immediately starts the PID control algorithm to respond. The PID algorithm quickly responds to large deviations through the proportional control part, the integral control part eliminates the cumulative error, and the differential control part is used to suppress the rapid fluctuations of the system, making the control adjustment smoother and more accurate. Based on the calculation results of the PID algorithm, the control device further optimizes the opening of each valve in the mixer, including adjusting the flow ratio of the superheated steam channel and the saturated water channel, thereby gradually eliminating the deviation value.

[0081] The dynamic correction function of PID control can adapt to changes in steam injection demand under complex working conditions. For example, when the demand for steam injection in the well fluctuates due to changes in the external environment or well conditions, PID control can make rapid adjustments within milliseconds to ensure that the temperature, pressure and flow rate of the output steam always meet the requirements. In addition, PID control effectively avoids the over-adjustment or lag problems that may occur in traditional fixed-proportional control through real-time feedback adjustment. In a possible implementation, Figure 2, a specific structural diagram of a molten salt heated superheated steam generating system is provided. In order to facilitate the introduction of the system working process, the water supply device is only preheated by steam. It is provided with a preheated water pipe 1 of the water supply device, an evaporator 2 of the evaporation device, a steam extraction pipe 3, a first wet steam pipe 4, a second wet steam pipe 5, a second hot salt pipe 6, a steam-water separator 7 of the superheated steam generating device, a separation water pipe 8, a dry steam pipe 9, a superheater 10, a first superheated steam pipe 11, a mixer 12, a second superheated steam pipe 13, a first hot salt pipe 14, a cold salt pipe 15, a preheater 16, an oilfield produced water supply pipe 17, a condensate pipe 18, etc.

[0082] In combination with the embodiment, the working principles and processes of each part of the system are specifically as follows.

[0083] 1. The main equipment of the invention is composed of a preheater 16, an evaporator 2, a steam-water separator 7, a superheater 10 and a blender 12.

[0084] 2. The produced water from the oil field is connected to the preheater 16 through the produced water supply pipe 17. After being heated in the preheater 16, the produced water from the oil field is connected to the evaporator 2 through the preheating water pipe 1. Taking the use of binary molten salt as an example, the freezing point of binary molten salt is 220°C, the produced water supply temperature of the oil field is 40-70°C, and the preheating water temperature is 230-250°C; the silicon content of the produced water from the oil field can be <250mg / L.

[0085] 3. The evaporator 2 may be composed of one or more heat exchangers; if the need for intermediate regulation is not considered, the evaporator may be provided with only one heat exchanger; if the need for intermediate regulation is considered, the evaporator may be provided with two or more heat exchangers.

[0086] 4. The produced water from the oil field is heated by molten salt in the evaporator 2 to become wet saturated steam, which is output through the first wet steam pipeline 4. A part of the wet saturated steam is connected to the preheater 16 through the extraction pipeline 3 to heat the produced water from the oil field in the preheater; the other part of the wet saturated steam is connected to the steam-water separator 7 through the second wet steam pipeline 5; the parameters of the wet saturated steam produced by the evaporator can be 8MPa, 295℃, and 75% dryness.

[0087] 5. The wet saturated steam heated by the oil field produced water in the preheater 16 releases heat in the preheater 16 and becomes condensed water; the temperature of the condensed water is lower than 80°C.

[0088] 6. A part of the wet saturated steam connected to the steam-water separator 7 becomes dry steam, and the other part is called saturated water; the dry steam parameters can be 99%-100% dryness, with the dry steam mass accounting for 75% and the saturated water mass accounting for 25%.

[0089] 7. The saturated water separated from the steam-water separator 7 is connected to the mixer 12 via the separation water pipeline 8.

[0090] 8. The dry steam separated from the steam-water separator 7 is connected to the superheater 10 via the dry steam pipeline 9. In the superheater 10, the dry steam is heated by the high-temperature molten salt to become highly superheated steam; the highly superheated steam may have a superheat of 135°C.

[0091] 9. The highly superheated steam generated in the superheater 10 is connected to the mixer 12 via the first superheated steam pipe 11.

[0092] 10. In the mixer 12, the high superheated steam and saturated water are mixed to become low superheated steam, which is then transported to the steam injection well through the second superheated steam pipeline 13; the superheat of the low superheated steam can be 15-20°C.

[0093] 11. Molten salt is used as the heat source medium of the system. The high-temperature molten salt is connected to the superheater 10 through the first hot salt pipeline 14 to heat the dry steam into highly superheated superheated steam, and then connected to the evaporator 2 through the second hot salt pipeline 6 to heat the preheated water into wet saturated steam, and then discharged from the system through the cold salt pipeline 15. Taking binary molten salt as an example, the temperature of the high-temperature molten salt can be 560°C, and the temperature of the low-temperature molten salt after heat exchange can be 285°C.

[0094] Figure 3 1 is a flow chart of a method for controlling a molten salt heated superheated steam generation system provided by an embodiment of the present invention. Figure 3 As shown, an embodiment of the present invention provides a molten salt heating superheated steam generation system control method, the method comprising: Step S10: collecting real-time steam injection demand information, and performing target operation state simulation of the water supply device, the evaporation device and the superheated steam generation device respectively based on the steam injection demand information; Step S20: Based on the deviation values ​​between the real-time operating states of the water supply device, the evaporation device and the superheated steam generation device and the corresponding target operating states, respectively generate control schemes for the water supply device, the evaporation device and the superheated steam generation device; Step S30: Execute the control scheme to adjust the states of the water supply device, the evaporation device and the superheated steam generation device respectively.

[0095] Preferably, the water supply device includes: an oilfield produced water supply pipeline, which is used to input oilfield produced water as low-temperature supply water for the water supply device; a preheating module, which is connected to the oilfield produced water supply pipeline and is used to preheat the low-temperature supply water; the preheating module is connected to the evaporation device through a pipeline, and is used to transmit the preheated low-temperature supply water to the evaporation device.

[0096] Preferably, the preheating module comprises: a wet saturated steam preheating module, a solar energy preheating module and a geothermal energy preheating module, which are combined to perform preheating on the low-temperature supply water; the wet saturated steam of the wet saturated steam preheating module is obtained by separating the wet saturated steam output by the evaporation device, and is fed into the wet saturated steam preheating module based on a first wet steam pipeline; another part of the wet saturated steam output by the evaporation device is fed into the evaporation device based on a second wet steam pipeline; the solar energy preheating module comprises: a concentrating solar collector, which is arranged between the wet saturated steam preheating module and the oilfield produced water Between the water supply pipes, it is used to perform the first stage preheating of the low-temperature supply water; the geothermal energy preheating module includes: a geothermal heat exchanger, which is arranged in parallel with the concentrating solar collector, and combined with the concentrating solar collector to perform the first stage preheating of the low-temperature supply water; the geothermal heat exchanger is provided with a three-way valve; the water inlet of the three-way valve is used to merge the heating medium of the geothermal heat exchanger; the water outlet of the three-way valve leads to the preheating module and the molten salt heating module respectively; the valve opening and closing degree of the three-way valve leading to the preheating module and the molten salt heating module respectively is controlled based on the control module.

[0097] Preferably, the generation rule of the control scheme of the preheating module is as follows: based on historical steam injection data, real-time steam demand and oil well operating parameters, a corresponding LSTM model is constructed to predict the steam injection demand at a predetermined time in the future; based on the steam injection demand and the heat exchange efficiency of the evaporator, the low-temperature supply water preheating demand is determined; based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module, the heat exchange power to be supplemented of the geothermal energy preheating module that performs the preheating of the low-temperature supply water is determined; based on the heat exchange power to be supplemented of the geothermal energy preheating module, a control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module is generated, and based on the remaining heat exchange power of the geothermal energy preheating module, a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module is generated as the control scheme of the preheating module.

[0098] An embodiment of the present invention further provides a computer-readable storage medium, on which instructions are stored, which, when executed on a computer, enable the computer to execute the above-mentioned molten salt heated superheated steam generation system control method.

[0099] Those skilled in the art will understand that all or part of the steps in the method for implementing the above-mentioned embodiments can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions for making a single-chip microcomputer, a chip or a processor execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0100] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, the technical scheme of the embodiments of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0101] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A molten salt heated superheated steam generating system, characterized in that: The system comprises: A water supply device, an evaporation device and a superheated steam generating device connected in sequence; A molten salt flow pipe is provided from the superheated steam generating device to the evaporating device to provide a heat source to the superheated steam generating device and the evaporating device; The water supply device is used to preheat the low-temperature supply water and transmit the preheated low-temperature supply water to the evaporation device, so that the evaporation device converts the preheated low-temperature supply water into wet saturated steam; The superheated steam generating device is used to convert the wet saturated steam into superheated steam required for steam injection; A control device is used to perform operating state control of a water supply device, an evaporation device and a superheated steam generation device based on steam injection demand.

2. The system according to claim 1, characterized in that The water supply device comprises: Oilfield produced water supply pipeline, used to input oilfield produced water as low-temperature supply water for water supply equipment; A preheating module, connected to the oilfield produced water supply pipeline, for preheating the low-temperature supply water; The preheating module is connected to the evaporation device through a pipeline and is used to transmit the preheated low-temperature supply water to the evaporation device.

3. The system according to claim 2, characterized in that The preheating module comprises: The wet saturated steam preheating module, the solar energy preheating module and the geothermal energy preheating module are combined to perform preheating of the low-temperature supply water; The wet saturated steam of the wet saturated steam preheating module is obtained by separating the wet saturated steam output by the evaporation device, and is fed into the wet saturated steam preheating module through the first wet steam pipeline; Another part of the wet saturated steam output by the evaporation device is introduced into the evaporation device based on the second wet steam pipeline.

4. The system according to claim 2, characterized in that The solar preheating module comprises: A concentrating solar collector is arranged between the wet saturated steam preheating module and the oilfield produced water supply pipeline, and is used to perform the first stage preheating of the low-temperature supply water; The geothermal energy preheating module comprises: The geothermal heat exchanger is arranged in parallel with the concentrating solar thermal collector, and is combined with the concentrating solar thermal collector to perform the first stage preheating of the low-temperature supply water.

5. The system according to claim 4, characterized in that The geothermal heat exchanger is provided with a three-way valve; The water inlet of the three-way valve is used to collect the heating medium of the geothermal heat exchanger; The water outlets of the three-way valve lead to the preheating module and the molten salt heating module respectively; The opening and closing degrees of the three-way valves leading to the preheating module and the molten salt heating module are controlled based on the control module.

6. The system according to claim 5, characterized in that The control module is configured to: Based on historical steam injection data, real-time steam demand and oil well operating parameters, a corresponding LSTM model is constructed to predict the steam injection demand at a predetermined time in the future. Based on the steam injection demand and the heat exchange efficiency of the evaporator, determining the preheating demand of the low-temperature feed water; Based on the heat exchange powers of the real-time wet saturated steam preheating module and the solar preheating module, determining the heat exchange power to be supplemented of the geothermal energy preheating module for performing low-temperature feed water preheating; A control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module is generated based on the heat exchange power to be supplemented of the geothermal energy preheating module, and a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module is generated based on the remaining heat exchange power of the geothermal energy preheating module.

7. The system according to claim 6, characterized in that The method of determining the heat exchange power to be supplemented of the geothermal energy preheating module for preheating low-temperature supplied water based on the heat exchange power of the real-time wet saturated steam preheating module and the solar energy preheating module includes: Based on the collaborative game theory algorithm, the preheating module and the molten salt heating module are regarded as game parties to maximize the steam injection demand satisfaction rate and the molten salt heat storage efficiency to construct the corresponding objective function. The objective function is iteratively solved based on the Lagrangian relaxation method to obtain the optimal heat exchange power to be supplemented of the geothermal energy preheating module for preheating low-temperature feed water.

8. The system according to claim 7, characterized in that The objective function is expressed as: in, and Preset weighting factors representing the importance of produced water preheating demand and molten salt thermal storage demand, respectively; geothermal heat supply for preheating of produced water; Total preheating requirements for produced water; to supply geothermal heat allocated for molten salt heating; Target demand for molten salt heating.

9. The system according to claim 1, characterized in that The evaporation device includes a plurality of heat exchangers; Each heat exchanger is connected in series through a pipeline, the water inlet of the first heat exchanger is connected to the water outlet of the water supply device, and the water outlet of the last heat exchanger is the output port of the wet saturated steam; The molten salt flow pipe flows from the last heat exchanger to the first heat exchanger and returns from the first heat exchanger to the molten salt heating module.

10. The system according to claim 1, characterized in that The superheated steam generating device comprises: The steam-water separator is used to separate the incoming wet saturated steam into steam and water to obtain dry steam and saturated water respectively; The dry steam and saturated water outputted from the steam-water separator are connected to the superheater and blender through the dry steam pipeline and the separation water pipeline respectively; The superheater performs heat exchange with the molten salt flow-through pipe to convert dry steam into superheated steam.

11. The system according to claim 10, characterized in that The superheater is connected to another inlet of the blender through a first superheated steam pipeline so as to flow the superheated steam into the blender; The mixer is used to mix superheated steam and saturated water based on the gas injection demand to obtain superheated steam that meets the steam injection demand, and output the superheated steam to the steam injection well through the second superheated steam pipeline.

12. The system according to claim 11, characterized in that The control module is configured to: Based on the state information of superheated steam and saturated water entering the mixer, the corresponding heat balance model and flow balance model are constructed; Determine the mixing ratio of superheated steam and saturated water based on the heat balance model and the flow balance model; The valve opening of the mixer is regulated in real time according to the mixing ratio.

13. The system according to claim 12, characterized in that The heat balance model is expressed as: The flow balance model is expressed as: in, , and They are the mass flow rate of mixed steam, the mass flow rate of superheated steam and the mass flow rate of saturated water respectively; , and They are the specific enthalpy of mixed steam, the specific enthalpy of superheated steam and the specific enthalpy of saturated water respectively.

14. The system according to claim 12, characterized in that Determine the mixing ratio of superheated steam and saturated water based on the heat balance model and flow balance model, including: A joint solution is performed based on the heat balance model and the flow balance model to obtain the flow ratio of superheated steam to saturated water to determine the mixing ratio of superheated steam to saturated water.

15. The system according to claim 12, characterized in that After adjusting the valve opening of the blender in real time according to the mixing ratio, the control device is further configured to: Collect the state parameters of the superheated steam required for steam injection in real time, and identify the deviation between the state parameters of the superheated steam required for steam injection and the state parameters of the target superheated steam; Based on the deviation value, a PID control algorithm is executed to correct the valve opening of the mixing device to keep the deviation value between the actual superheated steam state parameter and the target superheated steam state parameter within a preset difference threshold range.

16. A molten salt heating superheated steam generation system control method, characterized in that: The method is applied to the molten salt heating superheated steam generation system according to any one of claims 1 to 15, and the method comprises: Collecting real-time steam injection demand information, and performing target operation state simulation of a water supply device, an evaporation device, and a superheated steam generation device respectively based on the steam injection demand information; Based on the deviation values ​​between the real-time operating states of the water supply device, the evaporation device and the superheated steam generation device and the corresponding target operating states, control schemes of the water supply device, the evaporation device and the superheated steam generation device are generated respectively; The control scheme is executed to respectively adjust the states of the water supply device, the evaporation device and the superheated steam generation device.

17. The method according to claim 16, characterized in that The water supply device comprises: Oilfield produced water supply pipeline, used to input oilfield produced water as low-temperature supply water for water supply equipment; A preheating module, connected to the oilfield produced water supply pipeline, for preheating the low-temperature supply water; The preheating module is connected to the evaporation device through a pipeline and is used to transmit the preheated low-temperature supply water to the evaporation device.

18. The method according to claim 17, characterized in that The preheating module comprises: The wet saturated steam preheating module, the solar energy preheating module and the geothermal energy preheating module are combined to perform preheating of the low-temperature supply water; The wet saturated steam of the wet saturated steam preheating module is obtained by separating the wet saturated steam output by the evaporation device, and is fed into the wet saturated steam preheating module through the first wet steam pipeline; Another part of the wet saturated steam output by the evaporation device is fed into the evaporation device through a second wet steam pipeline; The solar preheating module comprises: A concentrating solar collector is arranged between the wet saturated steam preheating module and the oilfield produced water supply pipeline, and is used to perform the first stage preheating of the low-temperature supply water; The geothermal energy preheating module comprises: a geothermal heat exchanger, arranged in parallel with the concentrating solar thermal collector, and in combination with the concentrating solar thermal collector, performing a first stage preheating of the low-temperature supply water; The geothermal heat exchanger is provided with a three-way valve; The water inlet of the three-way valve is used to collect the heating medium of the geothermal heat exchanger; The water outlets of the three-way valve lead to the preheating module and the molten salt heating module respectively; The opening and closing degrees of the three-way valves leading to the preheating module and the molten salt heating module are controlled based on the control module.

19. The method according to claim 18, characterized in that The generation rule of the control scheme of the preheating module is: Based on historical steam injection data, real-time steam demand and oil well operating parameters, a corresponding LSTM model is constructed to predict the steam injection demand at a predetermined time in the future. Based on the steam injection demand and the heat exchange efficiency of the evaporator, determining the preheating demand of the low-temperature feed water; Based on the heat exchange powers of the real-time wet saturated steam preheating module and the solar preheating module, determining the heat exchange power to be supplemented of the geothermal energy preheating module for performing low-temperature feed water preheating; A control scheme for the valve opening and closing degree of the three-way valve leading to the preheating module is generated based on the heat exchange power to be supplemented of the geothermal energy preheating module, and a control scheme for the valve opening and closing degree of the three-way valve leading to the molten salt heating module is generated based on the remaining heat exchange power of the geothermal energy preheating module, as the control scheme of the preheating module.

20. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, which, when executed on a computer, enable the computer to execute the molten salt heated superheated steam generation system control method as described in any one of claims 16-19.

Images