Self-adaptive recharging regulation method and system for geothermal tail water recharging into deep aquifer

Abstract

The application relates to a self-adaptive recharge control method and system for geothermal tail water recharge in a deep aquifer, and belongs to the technical field of geothermal tail water recharge. The self-adaptive recharge control method comprises the following steps: determining a current recharge monitoring layer according to the water injection depth of a current tail water recharge point in a recharge well; uniformly arranging the recharge monitoring layers along the vertical direction of the recharge well; obtaining the temperature gradient of the current recharge monitoring layer; calculating the heat diffusion rate according to the temperature gradient; judging whether the heat diffusion rate exceeds a rate threshold value; if yes, obtaining the rate difference value between the heat diffusion rate and the rate threshold value; determining a recharge adjustment level according to the rate difference value, and determining a recharge adjustment strategy according to the recharge adjustment level. The application has the beneficial effects of reducing heat energy waste and heat pollution caused to the surrounding environment during tail water recharge.

Description

Technical Field

[0001] The present application relates to the technical field of geothermal tailwater reinjection, and in particular to a method and system for adaptive reinjection control of deep aquifers in geothermal tailwater reinjection. Background Art

[0002] Geothermal tailwater recharge technology plays a crucial role in renewable energy utilization. With the continued development of geothermal energy, the efficient and safe recharge of geothermal tailwater into medium- and deep-water aquifers has become a hot topic of research. Appropriate recharge technology not only enables the sustainable utilization of geothermal resources but also effectively protects groundwater resources and the ecological environment, playing a crucial role in promoting the development of clean energy. Currently, geothermal tailwater recharge is widely used in geothermal heating, power generation, and other fields, and its technological advancements provide strong support for reducing carbon emissions and lowering energy costs.

[0003] To address potential issues during geothermal tailwater reinjection, several approaches are commonly used: first, temperature monitoring at a single monitoring point at a fixed depth to assess reinjection effectiveness; second, relying on experience to adjust injection parameters, such as injection rate and pressure; and third, regularly checking the operating status of the reinjection well at preset intervals. While these methods can meet reinjection needs to a certain extent, they do have limitations.

[0004] These conventional methods are generally unable to accurately monitor recharge at different depths, making it difficult to promptly detect and address recharge risks caused by abnormal thermal diffusion. Especially in complex geological conditions, a single monitoring point is often unable to adapt to the changing recharge environment, which can easily lead to heat waste and thermal pollution to the surrounding environment. Summary of the Invention

[0005] In order to reduce heat energy waste and thermal pollution to the surrounding environment during tailwater reinjection, the present application provides an adaptive reinjection control method and system for deep aquifers in geothermal tailwater reinjection.

[0006] In a first aspect, the present application provides an adaptive reinjection control method for geothermal tailwater reinjection in deep aquifers, which adopts the following technical solutions:

[0007] An adaptive reinjection control method for geothermal tailwater reinjection in a deep aquifer, comprising:

[0008] Determine the current recharge monitoring layer according to the injection depth of the current tailwater recharge point in the recharge well; and evenly distribute the recharge monitoring layers vertically along the recharge well;

[0009] Obtaining the temperature gradient of the current recharge monitoring layer;

[0010] calculating a heat diffusion rate according to the temperature gradient;

[0011] determining whether the heat diffusion rate exceeds a rate threshold;

[0012] If yes, obtaining the rate difference between the heat diffusion rate and the rate threshold;

[0013] A recharge adjustment level is determined according to the rate difference, and a recharge adjustment strategy is determined according to the recharge adjustment level.

[0014] By adopting the above technical solution, by evenly distributing the recharge monitoring layers vertically in the recharge wells and determining the current recharge monitoring layer based on the injection depth of the current tailwater recharge point, it is possible to accurately monitor the recharge situation at different depths. The heat diffusion rate is calculated based on the temperature gradient, and recharge adjustments are made based on the comparison between this rate and the threshold. This achieves fine-grained regulation of the recharge process, effectively avoiding recharge problems caused by abnormal heat diffusion. It can automatically determine the recharge adjustment level and strategy based on the actual heat diffusion rate and has strong adaptive capabilities. When the heat diffusion rate exceeds the threshold, the system will respond in a timely manner and make reasonable adjustments based on the rate difference to ensure the stability and safety of the recharge process. By precisely regulating the recharge process, the thermal energy of geothermal tailwater can be better utilized and heat energy waste can be reduced. A rational reinjection strategy can more effectively circulate geothermal tailwater within medium- and deep-water aquifers, improving the overall utilization efficiency of geothermal resources and reducing energy costs. It effectively controls the rate of heat diffusion, preventing excessive heat dissipation within the aquifer, minimizing thermal pollution to the surrounding environment and maintaining relatively stable groundwater temperatures. This helps maintain the balance of underground ecosystems and protects the quality of groundwater resources. By rationally utilizing geothermal tailwater and reinjecting it into medium- and deep-water aquifers, geothermal resources can be recycled. This reduces reliance on traditional energy sources, lowers carbon emissions, and positively promotes environmental protection and sustainable development.

[0015] Optionally, the step of calculating the thermal diffusion rate according to the temperature gradient is:

[0016] The temperature gradient is input into the thermal diffusion rate model to obtain the thermal diffusion rate; the thermal diffusion rate model is is the temperature gradient, is the thermal conductivity of the recharge monitoring layer, is the density, is the specific heat capacity.

[0017] Optionally, the steps of determining a recharge adjustment level according to the rate difference, and determining a recharge adjustment strategy according to the recharge adjustment level are specifically:

[0018] If the rate difference is not greater than the first threshold, the recharge adjustment level is determined to be level one, and the adjustment strategy is to reduce the injection flow rate of the current recharge monitoring layer and perform intermittent water injection;

[0019] If the rate difference is greater than the first threshold value and not greater than the second threshold value, the recharge adjustment level is determined to be level 2, and the adjustment strategy is to switch to the adjacent water injection layer;

[0020] If the rate difference is greater than the second threshold, the reinjection adjustment level is determined to be level three, and the adjustment strategy is to switch the main fracture water injection layer.

[0021] By employing the above technical solution, different recharge adjustment levels are defined based on the rate difference, and corresponding adjustment strategies are applied. This allows recharge operations to be precisely adjusted based on actual conditions. For example, when the rate difference is small (less than the first threshold), the strategy of reducing the injection flow rate in the current recharge monitoring layer and implementing intermittent injection can prevent overinjection from impacting the recharge system and ensure stable operation. When the rate difference is large (greater than the second threshold), the strategy of switching the injection layer within the main fracture can effectively increase the recharge rate. In the first-level adjustment, reducing the injection flow rate and implementing intermittent injection allows the injected water more time to be absorbed by the formation, reducing water waste and avoiding the loss of some water due to ineffective infiltration during continuous high-flow injection. Switching injection layers in the second and third-level adjustment strategies fully utilizes the recharge capacity of different formations, ensuring the optimal allocation of water resources across different injection layers and improving overall water resource utilization efficiency. When the rate difference is abnormal, timely adjustment of the recharge strategy can reduce excessive disturbance to the formation. Precisely adjusting the recharge strategy based on the rate difference avoids the need for blind, large-scale adjustment measures.

[0022] Optionally, the step of switching the water injection layer includes:

[0023] Calculate the heat capacity of each reinjection monitoring layer;

[0024] Screen the recharge monitoring layer with heat capacity greater than 1.2 times the heat capacity of the current recharge monitoring layer as the candidate layer;

[0025] Determine the candidate layer closest to the current recharge monitoring layer as the adjacent water injection layer; , H is the heat capacity of the recharge monitoring layer, V is the volume of the recharge monitoring layer, and T is the temperature of the recharge monitoring layer;

[0026] The step of switching the main fracture water injection layer includes:

[0027] Collect temperature data of each recharge monitoring layer;

[0028] Generate a corresponding temperature field according to the temperature data of each layer;

[0029] determining the main cracks in the corresponding recharge monitoring layer according to the temperature field;

[0030] The reinjection monitoring layer with the largest main fracture is selected as the main fracture water injection layer.

[0031] By employing this technical solution, candidate layers with heat capacities greater than 1.2 times those of the current layer are screened, ensuring that the new injection layer possesses higher heat storage or seepage capacity. Selecting layers with high heat storage capacity makes injected water more easily absorbed by the formation. This approach combines the physical properties of the formation with dynamic temperature fluctuations to avoid the loss of efficiency caused by blind switching. Selecting the candidate layer closest to the currently monitored layer reduces hydraulic disturbances caused by switching injection layers, maintains formation pressure balance, and mitigates environmental risks. Dynamic heat capacity screening and adjacent layer switching strategies reduce flow fluctuations caused by insufficient injection layer capacity.

[0032] By collecting multi-dimensional temperature data to generate a temperature field, we can accurately locate the main fractures in recharge wells. Areas of temperature anomaly typically correspond to active fracture zones. Combined with analysis of formation heat conductivity characteristics, this method can improve the accuracy of fracture identification. Selecting the recharge monitoring layer with the largest main fracture as a candidate layer can increase the tailwater recharge rate and further enhance the tailwater recharge flow rate.

[0033] Optionally, the adaptive recharge control method further includes:

[0034] The first threshold and the second threshold are dynamically adjusted according to the equivalent permeability and the fracture roughness.

[0035] By employing this technical solution, the first threshold (the primary adjustment threshold) and the second threshold (the third adjustment threshold) can be dynamically adjusted by real-time calculation of equivalent permeability (reflecting the formation's water storage capacity) and fracture roughness (characterizing the fracture surface morphology). For example, when permeability is high, a larger rate difference (increasing the threshold) is allowed to avoid frequent triggering of injection zone switching; when fracture roughness increases (e.g., increased surface roughness), the threshold is lowered to trigger plugging operations earlier and prevent fracture expansion. This allows the first and second thresholds to dynamically adapt to formation characteristics.

[0036] Optionally, the step of dynamically adjusting the first threshold and the second threshold according to the equivalent permeability and the fracture roughness includes:

[0037] Calculating the fracture roughness of the current recharge monitoring layer;

[0038] Determining whether the crack roughness is greater than a roughness threshold;

[0039] If so, lowering the first threshold and the second threshold;

[0040] If not, then calculating the equivalent permeability of the current recharge monitoring layer;

[0041] determining whether the equivalent permeability is greater than a permeability threshold;

[0042] If so, increase the first threshold and the second threshold.

[0043] By employing this technical solution, when the fracture roughness exceeds the roughness threshold, lowering the first and second thresholds can trigger injection layer switching or fracture plugging operations in advance. For example, when the roughness exceeds the limit, the complex fracture surface morphology will increase water flow resistance. In this case, lowering the threshold can prevent formation collapse caused by fracture expansion. When the equivalent permeability exceeds the permeability threshold, raising the threshold allows for a larger rate difference, avoiding frequent strategy adjustments due to the high water storage capacity of the high-permeability layer.

[0044] Optionally, the crack roughness is is the angle between the local normal vector and the main penetration direction, is the maximum deviation angle;

[0045] The equivalent permeability is is the porosity, is the matrix permeability, is the fracture permeability, , b is the average crack opening, and S is the crack spacing.

[0046] Optionally, the adaptive recharge control method further includes:

[0047] The first threshold , the second threshold , is the historical mean of the rate difference, n is the sensitivity coefficient, is the standard deviation of the rate difference;

[0048] Increasing the first threshold and the second threshold refers to increasing n; decreasing the first threshold and the second threshold refers to decreasing n;

[0049] When the crack roughness is greater than the roughness threshold and the equivalent permeability is less than the permeability threshold, the first threshold and the second threshold are maintained unchanged, and a third threshold is generated. , All are adjustment coefficients;

[0050] Determining whether the rate difference is not less than the third threshold;

[0051] If so, the water injection flow rate of the current recharge monitoring layer is reduced, water is injected intermittently, and the frequency of fracture monitoring is increased.

[0052] By adopting the above technical solution, a dual-parameter correlation model is established to achieve a coupled response of roughness and permeability, further enhancing the adaptability to complex geological conditions.

[0053] In a second aspect, the present application provides an adaptive reinjection control system for geothermal tailwater reinjection in deep aquifers, which adopts the following technical solutions:

[0054] An adaptive recharge control system for geothermal tailwater recharge in deep aquifers, comprising:

[0055] The pre-processing module is used to determine the current recharge monitoring layer according to the water injection depth of the current tailwater recharge point in the recharge well; and to evenly distribute the recharge monitoring layers vertically along the recharge well;

[0056] A data acquisition module, configured to obtain the temperature gradient of the current recharge monitoring layer;

[0057] A data processing module, configured to calculate a heat diffusion rate based on the temperature gradient;

[0058] a judgment module, configured to judge whether the heat diffusion rate exceeds a rate threshold; if so, the data processing module obtains a rate difference between the heat diffusion rate and the rate threshold;

[0059] The recharge strategy module is configured to determine a recharge adjustment level according to the rate difference, and determine a recharge adjustment strategy according to the recharge adjustment level.

[0060] In summary, this application has at least the following beneficial effects:

[0061] By evenly distributing recharge monitoring layers vertically along the recharge wells and determining the current recharge monitoring layer based on the injection depth of the current tailwater recharge point, it is possible to accurately monitor the recharge situation at different depths. The heat diffusion rate is calculated based on the temperature gradient, and recharge adjustments are made based on the comparison of this rate with the threshold. This enables fine-grained regulation of the recharge process, effectively avoiding recharge problems caused by abnormal heat diffusion. The system can automatically determine the recharge adjustment level and strategy based on the actual heat diffusion rate, and has strong adaptive capabilities. When the heat diffusion rate exceeds the threshold, the system will respond promptly and make reasonable adjustments based on the rate difference to ensure the stability and safety of the recharge process. By precisely regulating the recharge process, the thermal energy of geothermal tailwater can be better utilized, reducing heat energy waste. A rational reinjection strategy can more effectively circulate geothermal tailwater within medium- and deep-water aquifers, improving the overall utilization efficiency of geothermal resources and reducing energy costs. It effectively controls the rate of heat diffusion, preventing excessive heat dissipation within the aquifer, minimizing thermal pollution to the surrounding environment and maintaining relatively stable groundwater temperatures. This helps maintain the balance of underground ecosystems and protects the quality of groundwater resources. By rationally utilizing geothermal tailwater and reinjecting it into medium- and deep-water aquifers, geothermal resources can be recycled. This reduces reliance on traditional energy sources, lowers carbon emissions, and positively promotes environmental protection and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a flowchart of an implementation method of Example 1 of the present application;

[0063] Figure 2 This is a flowchart of another embodiment of the method of the present application;

[0064] Figure 3 It is a structural block diagram of an implementation method of the system embodiment of the present application. DETAILED DESCRIPTION

[0065] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the appended drawings of the embodiments of the present invention. Figure 1 -Attached Figure 3 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0066] The first embodiment of the present application discloses an adaptive recharge control method for geothermal tail water recharge in deep aquifers. Figure 1 As an implementation of the adaptive recharge control method, the adaptive recharge control method may include S110-S170:

[0067] S110, determining a current recharge monitoring layer according to the injection depth of the current tailwater recharge point in the recharge well;

[0068] S120, obtaining the temperature gradient of the current recharge monitoring layer;

[0069] S130, calculating the thermal diffusion rate according to the temperature gradient;

[0070] S140, determining whether the heat diffusion rate exceeds a rate threshold;

[0071] S150, if yes, obtaining the rate difference between the heat diffusion rate and the rate threshold;

[0072] S160, determining a recharge adjustment level according to the rate difference, and determining a recharge adjustment strategy according to the recharge adjustment level;

[0073] S170, if not, return to S140.

[0074] Specifically, within a 3km radius around the recharge well group, DTS temperature measurement optical fibers are laid out at a vertical spacing of 5m. Each temperature measurement optical fiber monitoring point plane serves as a recharge monitoring layer. The temperature measurement optical fiber is used to monitor the temperature gradient of the recharge monitoring layer (e.g. sandstone aquifer) in real time. ).

[0075] The temperature gradient is input into the thermal diffusion rate model to obtain the thermal diffusion rate; the thermal diffusion rate model is is the temperature gradient, is the thermal conductivity of the recharge monitoring layer (W / (m·K)), is the density (kg / m³), is the specific heat capacity (J / (kg·K)). These are all known quantities and can be obtained through historical monitoring pressure data combined with conventional fluid mechanics and heat conduction theory. For example, pressure sensors can be used to measure pressure changes in the reinjection monitoring layer during water injection, and a coupled pressure-temperature-thermophysical property model can be established. The model can then be solved to obtain the thermal conductivity, specific heat capacity, and density of the reinjection monitoring layer. Research results and empirical data from other regions with similar geological conditions and water injection scenarios can also be used to make analogical estimates of the thermal conductivity, specific heat capacity, and density of the target reinjection monitoring layer. There is no limit to the method of obtaining these quantities.

[0076] After obtaining the heat diffusion rate, obtain the rate difference between the heat diffusion rate and the rate threshold; for example, the rate threshold is 0.8 m / h; , which is greater than the rate threshold, so the current recharge monitoring layer is marked as a high-risk area for thermal breakthrough, and dynamic recharge adjustment is required.

[0077] Specifically for S160:

[0078] If the rate difference is not greater than the first threshold, the recharge adjustment level is determined to be level one, and the adjustment strategy is to reduce the injection flow rate of the current recharge monitoring layer and perform intermittent water injection;

[0079] If the rate difference is greater than the first threshold and not greater than the second threshold, the reinjection adjustment level is determined to be level 2, and the adjustment strategy is to switch to the adjacent injection layer;

[0080] If the rate difference is greater than the second threshold, the reinjection adjustment level is determined to be level three, and the adjustment strategy is to switch the main fracture water injection layer.

[0081] Specifically, for the first level of reinjection adjustment, the absolute value of the difference between the rate difference and the first threshold is obtained. The percentage of the absolute value of the difference to the first threshold is the percentage of water injection flow reduction. For intermittent water injection, the absolute value of the difference can be divided into levels based on how close it is to the first threshold. The water injection cycle is then adjusted based on the level of the absolute value of the difference. For example, if the absolute value of the difference is in level 1, the water injection cycle can be a pulse cycle of "injection for 10 minutes and suspension for 5 minutes."

[0082] Specifically for the secondary recharge adjustment level:

[0083] The heat capacity of each recharge monitoring layer needs to be calculated. Then, recharge monitoring layers with a heat capacity greater than 1.2 times the heat capacity of the current recharge monitoring layer are selected as candidate layers. The candidate layer closest to the current recharge monitoring layer is then determined as the adjacent water injection layer. The tailwater is then redirected from the current recharge monitoring layer to the adjacent water injection layer. After the candidate layers are selected, the vertical distance between each candidate layer and the current recharge monitoring layer is calculated. The candidate layer with the smallest vertical distance is the candidate layer closest to the current recharge monitoring layer.

[0084] , H is the heat capacity of the recharge monitoring layer, V is the volume of the recharge monitoring layer, and T is the temperature of the recharge monitoring layer.

[0085] Specifically for the three-level recharge adjustment level:

[0086] Temperature data from each recharge monitoring layer can be collected using temperature-measuring optical fibers. Based on this data, a corresponding temperature field is generated. This temperature field can then be used to identify the primary fractures in the recharge monitoring layer. The recharge monitoring layer with the largest or most primary fractures is then selected as the primary fracture injection layer. The location of the primary fracture is indicated by temperature mutation points (gradient > 0.5°C / m). More temperature mutation points indicate more primary fractures, and greater temperature mutations indicate larger primary fractures. Monitoring the expansion direction of the temperature field during recharge reveals that the thermal plume leading to the primary fracture is distributed in a narrow, long ribbon. Determining the temperature field from temperature data is a conventional technique and will not be described in detail.

[0087] In another embodiment, the first threshold and the second threshold may be dynamically adjusted according to the equivalent permeability and the fracture roughness.

[0088] Reference Figure 2 The dynamic adjustment steps may specifically include S210-S300:

[0089] S210, calculating the fracture roughness of the current recharge monitoring layer;

[0090] S220, determining whether the crack roughness is greater than a roughness threshold;

[0091] S230, if yes, lower the first threshold and the second threshold;

[0092] S240, if not, calculating the equivalent permeability of the current recharge monitoring layer;

[0093] S250, determining whether the equivalent permeability is greater than a permeability threshold;

[0094] S260, if yes, increase the first threshold and the second threshold;

[0095] S270, if not, maintaining the first threshold and the second threshold unchanged, and generating a third threshold;

[0096] S280, determining whether the rate difference is not less than a third threshold;

[0097] S290, if yes, reduce the current injection flow rate of the recharge monitoring layer, perform intermittent water injection, and increase the frequency of fracture monitoring;

[0098] S300, if not, return to S160.

[0099] Specifically, the crack roughness is is the angle between the local normal vector and the main penetration direction, is the maximum deviation angle; the equivalent permeability is ; is the porosity, is the matrix permeability, is the fracture permeability, , b is the average crack opening, and S is the crack spacing.

[0100] First threshold , the second threshold , is the historical mean of the rate difference, n is the sensitivity coefficient, is the standard deviation of the rate difference;

[0101] Increasing the first threshold and the second threshold refers to increasing n; decreasing the first threshold and the second threshold refers to decreasing n.

[0102] The third threshold , These are adjustment coefficients; they can be set manually or obtained based on historical relevant threshold data.

[0103] When the difference between the rate difference and the third threshold is greater, the monitoring frequency of the crack is higher.

[0104] A scenario of this embodiment is as follows:

[0105] According to the injection depth of the current tailwater reinjection point in the reinjection well, the current reinjection monitoring layer is determined, and then the temperature gradient of the current reinjection monitoring layer is obtained and the thermal diffusion rate is calculated to determine whether the thermal diffusion rate exceeds the rate threshold. If so, the rate difference between the thermal diffusion rate and the rate threshold is obtained. If the rate difference is not greater than the first threshold, the reinjection adjustment level is determined to be level one, and the adjustment strategy is to reduce the injection flow rate of the current reinjection monitoring layer and intermittently inject water;

[0106] In addition, the crack roughness and equivalent permeability of the current recharge monitoring layer can be calculated in real time; if the crack roughness is greater than the roughness threshold and the equivalent permeability is less than the permeability threshold, a third threshold is generated. After the rate difference is obtained, if it is judged that the rate difference is greater than the third threshold, the injection flow rate of the current recharge monitoring layer is reduced, intermittent water injection is performed, and the monitoring frequency of the cracks is increased.

[0107] Based on the above method embodiment, the second embodiment of the present application discloses an adaptive reinjection control system for geothermal tail water reinjection in deep aquifers. Figure 3 As an embodiment of the adaptive recharge control system, the adaptive recharge control system may include:

[0108] The pre-processing module is used to determine the current recharge monitoring layer according to the injection depth of the current tailwater recharge point in the recharge well; and to evenly distribute the recharge monitoring layers vertically along the recharge well;

[0109] A data acquisition module is used to obtain the temperature gradient of the current recharge monitoring layer;

[0110] A data processing module is used to calculate the heat diffusion rate based on the temperature gradient;

[0111] A judgment module is used to judge whether the heat diffusion rate exceeds a rate threshold; if so, the data processing module obtains the rate difference between the heat diffusion rate and the rate threshold;

[0112] The recharge strategy module is used to determine the recharge adjustment level according to the rate difference, and determine the recharge adjustment strategy according to the recharge adjustment level.

[0113] The modules of the adaptive reinjection control system for geothermal tail water reinjection into deep aquifers correspond one to one with the adaptive reinjection control method for geothermal tail water reinjection into deep aquifers, and no further details will be given here.

[0114] The above are all preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. Unless otherwise specified, any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features. In other words, unless otherwise specified, each feature is merely an example of a series of equivalent or similar features.

Claims

1. An adaptive recharge control method for geothermal tailwater recharge in deep aquifers, characterized in that: include: Determine the current recharge monitoring layer according to the injection depth of the current tailwater recharge point in the recharge well; Recharge monitoring layers are evenly distributed vertically along the recharge well; Obtaining the temperature gradient of the current recharge monitoring layer; calculating a heat diffusion rate according to the temperature gradient; determining whether the heat diffusion rate exceeds a rate threshold; If yes, obtaining the rate difference between the heat diffusion rate and the rate threshold; A recharge adjustment level is determined according to the rate difference, and a recharge adjustment strategy is determined according to the recharge adjustment level.

2. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 1, characterized in that: The step of calculating the thermal diffusion rate according to the temperature gradient is: The temperature gradient is input into the thermal diffusion rate model to obtain the thermal diffusion rate; the thermal diffusion rate model is is the temperature gradient, is the thermal conductivity of the recharge monitoring layer (W / (m·K)), is the density (kg / m³), is the specific heat capacity (J / (kg·K)).

3. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 1, characterized in that: The steps of determining the recharge adjustment level according to the rate difference and determining the recharge adjustment strategy according to the recharge adjustment level are specifically as follows: If the rate difference is not greater than the first threshold, the recharge adjustment level is determined to be level one, and the adjustment strategy is to reduce the injection flow rate of the current recharge monitoring layer and perform intermittent water injection; If the rate difference is greater than the first threshold value and not greater than the second threshold value, the recharge adjustment level is determined to be level 2, and the adjustment strategy is to switch to the adjacent water injection layer; If the rate difference is greater than the second threshold, the reinjection adjustment level is determined to be level three, and the adjustment strategy is to switch the main fracture water injection layer.

4. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 3, characterized in that: The step of switching the adjacent water injection layer includes: Calculate the heat capacity of each reinjection monitoring layer; Screen the recharge monitoring layer with heat capacity greater than 1.2 times the heat capacity of the current recharge monitoring layer as the candidate layer; Determine the candidate layer closest to the current recharge monitoring layer as the adjacent water injection layer; , H is the heat capacity of the recharge monitoring layer, V is the volume of the recharge monitoring layer, and T is the temperature of the recharge monitoring layer; The step of switching the main fracture water injection layer includes: Collect temperature data of each recharge monitoring layer; Generate a corresponding temperature field according to the temperature data of each layer; determining the main cracks in the corresponding recharge monitoring layer according to the temperature field; The reinjection monitoring layer with the largest main fracture is selected as the main fracture water injection layer.

5. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 3, characterized in that: The adaptive recharge control method further includes: The first threshold and the second threshold are dynamically adjusted according to the equivalent permeability and the fracture roughness.

6. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 5, characterized in that: The step of dynamically adjusting the first threshold and the second threshold according to the equivalent permeability and the fracture roughness includes: Calculating the fracture roughness of the current recharge monitoring layer; Determining whether the crack roughness is greater than a roughness threshold; If so, lowering the first threshold and the second threshold; If not, then calculating the equivalent permeability of the current recharge monitoring layer; determining whether the equivalent permeability is greater than a permeability threshold; If so, increase the first threshold and the second threshold.

7. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 6, characterized in that: The crack roughness is , is the angle between the local normal vector and the main penetration direction, is the maximum deviation angle.

8. The adaptive recharge control method for geothermal tail water recharge in deep aquifers according to claim 7, characterized in that: The adaptive recharge control method further includes: The first threshold , the second threshold , is the historical mean of the rate difference, n is the sensitivity coefficient, is the standard deviation of the rate difference; When the crack roughness is not greater than the roughness threshold and the equivalent permeability is not greater than the permeability threshold, the first threshold and the second threshold are maintained unchanged, and a third threshold is generated. , and are adjustment coefficients, is the equivalent permeability; Determining whether the rate difference is not less than the third threshold; If so, the water injection flow rate of the current recharge monitoring layer is reduced, water is injected intermittently, and the frequency of fracture monitoring is increased.

9. An adaptive recharge control system for geothermal tailwater recharge in deep aquifers, characterized by: The method for adaptively controlling the reinjection of geothermal tail water into a deep aquifer according to any one of claims 1 to 8 comprises: The pre-processing module is used to determine the current recharge monitoring layer according to the water injection depth of the current tailwater recharge point in the recharge well; and to evenly distribute the recharge monitoring layers vertically along the recharge well; A data acquisition module, configured to obtain the temperature gradient of the current recharge monitoring layer; A data processing module, configured to calculate a heat diffusion rate based on the temperature gradient; a judgment module, configured to judge whether the heat diffusion rate exceeds a rate threshold; if so, the data processing module obtains a rate difference between the heat diffusion rate and the rate threshold; The recharge strategy module is configured to determine a recharge adjustment level according to the rate difference, and determine a recharge adjustment strategy according to the recharge adjustment level.

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