Method for calculating thermal breakthrough time of geothermal-to-well extraction and injection system based on temperature drop constraint

Abstract

The invention belongs to the technical field of data processing, and relates to a terrestrial heat-to-well production and injection system thermal breakthrough time calculation method based on temperature drop constraint, which comprises the following steps: acquiring terrestrial heat-to-well production and injection data, and inputting the terrestrial heat-to-well production and injection data into a thermal breakthrough time calculation model, obtaining thermal breakthrough time calculation results of terrestrial heat on the well exploitation and irrigation system under different exploitation and irrigation amounts, exploitation and irrigation well spacing and allowable temperature drop conditions; wherein the thermal breakthrough time calculation model is obtained by combining a thermal breakthrough time analysis framework based on allowable temperature drop constraint with an energy conservation principle. Based on the principle of conservation of energy, namely the first law of thermodynamics, a thermal breakthrough time calculation model of the mining well is deduced on the basis that the temperature of the mining well is allowed to be reduced to a certain extent, the thermal breakthrough occurrence time of the mining well is accurately predicted, and therefore a scientific basis is provided for optimization design of a geothermal-to-well mining and injection system; the purposes of prolonging the service life of a geothermal system, improving the exploitation efficiency of geothermal resources and guaranteeing sustainable development of medium-deep geothermal resources are achieved.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and in particular to a method for calculating the thermal breakthrough time of geothermal well production and irrigation systems based on temperature drop constraints. Background Technology

[0002] Geothermal resources are being used more widely worldwide as a direct energy source, providing a practical alternative to fossil fuels.

[0003] Existing technologies utilize geothermal water for large-scale community heating. Sedimentary basin geothermal energy is characterized by its wide distribution of thermal reservoirs, large thickness, uniform water-bearing medium, strong permeability and water conductivity, large single-well water output, and abundant reserves, making it the region with the greatest potential for geothermal resource development.

[0004] In recent years, with increasingly tight energy supplies and severe environmental problems, geothermal energy has gradually gained attention, sparking a surge in geothermal development. Geothermal reinjection plays a crucial role in improving geothermal resource utilization, reducing wastewater discharge, maintaining reservoir pressure, and achieving sustainable geothermal resource utilization. However, because the temperature of the reinjected geothermal wastewater is much lower than the reservoir temperature, reinjection inevitably leads to a decrease in reservoir temperature. When the cold front of the reinjected wastewater migrates to the production well, it causes a thermal breakthrough. As the water temperature in the production well continues to decrease, the utilization rate of geothermal resources also rapidly declines until it becomes unprofitable.

[0005] Therefore, studying the temperature changes in production wells caused by geothermal tailwater reinjection is of great significance. Existing technologies use the initial temperature drop in the production well as the thermal breakthrough standard. However, when the reservoir temperature is higher than the engineering requirements, or when the maximum production-injection well distance is limited, the water temperature produced by the production well may be inaccurate. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to provide a method for calculating the thermal breakthrough time of a geothermal well-to-well production and irrigation system based on temperature drop constraints. Based on the principle of energy conservation (the first law of thermodynamics), a calculation model for the thermal breakthrough time of the production well is derived on the premise that the temperature of the production well can be reduced to a certain extent. This method accurately predicts the occurrence time of the thermal breakthrough in the production well, thereby providing a scientific basis for the optimized design of the geothermal well-to-well production and irrigation system, and achieving the goals of extending the service life of the geothermal system, improving the efficiency of geothermal resource extraction, and ensuring the sustainable development of medium and deep geothermal resources.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A method for calculating the thermal breakthrough time of geothermal well production and irrigation systems based on temperature drop constraints includes:

[0009] Obtain geothermal well extraction and irrigation data, input the geothermal well extraction and irrigation data into the thermal breakthrough time calculation model, and obtain the thermal breakthrough time calculation results of the geothermal well extraction and irrigation system under different extraction and irrigation volumes, extraction and irrigation well spacing and allowable temperature drop conditions;

[0010] The thermal breakthrough time calculation model is obtained by combining the thermal breakthrough time analysis framework based on allowable temperature drop constraints with the principle of energy conservation.

[0011] Optionally, the geothermal well extraction and irrigation data includes: effective reservoir thickness, well spacing, extraction and irrigation volume, reinjection water density, reinjection water specific heat, porosity, reservoir rock density, reservoir rock specific heat, water extraction temperature, reinjection water temperature, and allowable temperature drop.

[0012] Optionally, constructing the thermal breakthrough time calculation model includes:

[0013] Obtain the original thermal breakthrough time calculation model, and use the original thermal breakthrough time calculation model to establish the thermal breakthrough time analysis framework;

[0014] The heat extracted by the surface heat exchange system is obtained, and based on the heat extracted by the surface heat exchange system, the characteristic relationship between the operating time of the production and irrigation wells and the reservoir thickness, production volume, and production-irrigation well distance is determined when the allowable temperature drop of the production well reservoir is reduced to the constraint temperature under the allowable temperature drop.

[0015] Based on the aforementioned thermal breakthrough time analysis framework and the aforementioned characteristic relationships, the thermal breakthrough time calculation model is obtained.

[0016] Optionally, establishing the thermal breakthrough time analysis framework includes:

[0017] ;

[0018] Where f represents the thermal breakthrough time t function of the geothermal well production and injection system with allowable temperature drop constraint, Q is the reinjection water volume, H is the effective thickness of the geothermal reservoir, ρ is the density of the geothermal reservoir, C is the specific heat capacity of the geothermal reservoir, r0 represents the distance between production and injection wells, T0 is the water intake temperature, T1 is the reinjection water temperature, and ΔT is the allowable temperature drop.

[0019] Optionally, determining the feature relationship includes:

[0020] ;

[0021] Where t represents the characteristic relationship between the operational time of the production-injection well and the reservoir thickness, production volume, and production-injection well distance; H represents the effective thickness of the reservoir; <ρC> represents the heat capacity per unit volume of the reservoir; T0 represents the water extraction temperature; T1 represents the reinjection water temperature; ΔT represents the allowable temperature drop; Q represents the reinjection water volume; and ρ w C represents the density of the recharge water. w This refers to the specific heat capacity of the reinjection water.

[0022] Optionally, obtaining the heat extracted by the surface heat exchange system includes:

[0023] The spacing between the production and injection wells is divided into multiple equal modules. The heat loss of the target width annular body from the injection well on the plane is determined. When the temperature of the production well drops to the constrained temperature, the heat loss of the thermal storage column from the injection well to the target radius is determined based on the heat loss of the target width annular body. When the radial distance x from the injection well is x=r0, the heat loss of the thermal storage column is adjusted, and the heat extracted by the surface heat exchange system is obtained using the adjusted heat loss of the thermal storage column.

[0024] Optionally, determining the heat loss of the thermal reservoir column from the reinjection well to the target radius includes:

[0025] ;

[0026] Among them, E lost ρC represents the heat loss of the reservoir column with radius x, H represents the effective thickness of the reservoir, <ρC> represents the heat capacity per unit volume of the reservoir, T0 represents the water intake temperature, T1 represents the reinjection water temperature, x represents the distance to the reinjection well, r0 represents the distance between the production and injection wells, and ΔT represents the allowable temperature drop.

[0027] Optionally, adjusting the heat loss of the thermal storage column includes:

[0028] ;

[0029] Among them, E lost The adjusted heat loss of the reservoir column is represented by r0, which indicates the distance between the production and injection wells, H is the effective thickness of the reservoir, <ρC> represents the heat capacity per unit volume of the reservoir, T0 is the water intake temperature, T1 is the reinjection water temperature, and ΔT is the allowable temperature drop.

[0030] Optionally, obtaining the heat extracted by the surface heat exchange system includes:

[0031] ;

[0032] Where Q is the reinjection water volume, t is the thermal breakthrough time of the geothermal well for the well-injection system, and ρ w C represents the density of the recharge water. w ρC represents the specific heat capacity of the reinjection water, T0 represents the water intake temperature, T1 represents the reinjection water temperature, r0 represents the distance between the production and injection wells, H represents the effective thickness of the thermal reservoir, and ΔT represents the allowable temperature drop.

[0033] The beneficial effects of this invention are as follows:

[0034] This invention allows for a certain degree of temperature reduction in production wells, thereby improving the applicability of predicting the thermal breakthrough time of production wells. It also derives a calculation model for the thermal breakthrough time of geothermal well production and irrigation systems that allows for temperature drop constraints, enabling more accurate prediction of the thermal breakthrough time of production wells under conditions where production well temperature reduction is permitted. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of the method for calculating the thermal breakthrough time of a geothermal well-to-injection system based on temperature drop constraints, according to an embodiment of the present invention.

[0037] Figure 2 This is a schematic diagram of a geothermal well extraction and irrigation project according to an embodiment of the present invention;

[0038] Figure 3 This is a planar position diagram of a ring with radius x and width dx, with the recharge well as the source point, according to an embodiment of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1 As shown in the figure, this embodiment discloses a method for calculating the thermal breakthrough time of a geothermal well-to-well extraction and irrigation system based on temperature drop constraints. The method includes: acquiring geothermal well-to-well extraction and irrigation data, inputting the geothermal well-to-well extraction and irrigation data into a thermal breakthrough time calculation model, and obtaining the thermal breakthrough time calculation results of the geothermal well-to-well extraction and irrigation system under different extraction and irrigation rates, well spacing, and allowable temperature drop conditions. The thermal breakthrough time calculation model is obtained by combining the thermal breakthrough time analysis framework based on allowable temperature drop constraints with the principle of energy conservation.

[0042] Further, constructing the thermal breakthrough time calculation model includes: obtaining the original thermal breakthrough time calculation model; using the original thermal breakthrough time calculation model to establish the thermal breakthrough time analysis framework; dividing the distance between the production and injection wells into multiple equal modules; determining the heat loss of the target width annular body from the injection well on the plane; when the temperature of the production well drops to the constraint temperature, determining the heat loss of the thermal reservoir column from the injection well to the target radius based on the heat loss of the target width annular body; when x=r0, adjusting the heat loss of the thermal reservoir column, and using the adjusted heat loss of the thermal reservoir column to obtain the heat extracted by the surface heat exchange system; based on the heat extracted by the surface heat exchange system, determining the characteristic relationship between the operable time of the production and injection wells and the thermal reservoir thickness, production volume, and distance between the production and injection wells when the thermal reservoir of the production well is allowed to drop to the constraint temperature under the allowable temperature drop; and obtaining the thermal breakthrough time calculation model based on the thermal breakthrough time analysis framework and the characteristic relationship.

[0043] Specifically, the basic framework and applicable conditions of the existing geothermal well production and irrigation system thermal breakthrough time calculation model are determined:

[0044] Applicable conditions: The thermal reservoir is horizontal and of uniform thickness; the overlying and underlying rock strata are impermeable; the initial temperature of the aquifer is the same as that of the overlying and underlying rock strata; the temperatures of the overlying and underlying rock strata are constant; the production rate and reinjection flow rate are stable; the reinjection water temperature is stable; horizontal and vertical heat conduction in the thermal reservoir is ignored; the water and rock in the thermal reservoir reach thermal equilibrium instantaneously; the temperature of the rock and water is the same; the heat transfer by heat conduction is negligible compared to the heat transfer by convection; after ignoring the heat conduction term, the cold front will move radially around the reinjection well.

[0045] Basic framework: Existing geothermal well-to-injection system thermal breakthrough time calculation model for production wells:

[0046] ;

[0047] In the formula, r0 represents the spacing between the production and irrigation wells; Q represents the reinjection water volume; t represents the thermal breakthrough time of the production well in the geothermal well-injection system; H represents the effective thickness of the geothermal reservoir (i.e., the thickness of the aquifer); ρ w Indicates the density of the recharge water; C w Indicates the specific heat capacity of the recharge water; This represents the heat capacity per unit volume of the thermal reservoir, i.e.:

[0048] ;

[0049] In the formula, φ represents the porosity of the thermal reservoir; ρ r C represents the density of thermal reservoir rocks. r This indicates the specific heat capacity of the geothermal reservoir rock.

[0050] The above formula is the calculation model for the thermal breakthrough time of existing geothermal well production and irrigation systems. Its basic framework is as follows:

[0051] ;

[0052] In the formula, f represents the thermal breakthrough time t of the well in the production and irrigation system, which is a function of the reinjection water volume Q, the designed production time t of the well production and irrigation system, the effective thickness H of the thermal reservoir, the density ρ of the thermal reservoir (including geothermal water and reservoir matrix), and the specific heat capacity C of the thermal reservoir (including geothermal water and reservoir matrix).

[0053] Since the temperature of the production well is allowed to decrease, the influence of the production temperature and the reinjection temperature needs to be considered. Therefore, the basic framework of the geothermal well production and injection system thermal breakthrough time calculation model with temperature drop constraints is adjusted as follows:

[0054] ;

[0055] In the formula, f represents the thermal breakthrough time t of the geothermal well production and injection system under the allowable temperature drop constraint. It is a function of the reinjection water volume Q, the design operating years of the well production and injection system t, the effective thickness of the thermal reservoir H, the density of the thermal reservoir ρ (including geothermal water and reservoir matrix), the specific heat capacity of the thermal reservoir C (including geothermal water and reservoir matrix), the water intake temperature T0, the reinjection water temperature T1, and the allowable temperature drop ΔT.

[0056] Derivation of a calculation model for the thermal breakthrough time of geothermal well production and irrigation systems with temperature drop constraints, and determination of applicable conditions:

[0057] Based on the basic framework for analyzing the thermal breakthrough time of geothermal well production and irrigation systems with allowable temperature drop constraints, and combined with the principle of energy conservation (the first law of thermodynamics), a calculation model for the thermal breakthrough time of geothermal well production and irrigation systems with allowable temperature drop constraints is derived.

[0058] Applicable conditions: The geothermal reservoir is homogeneous and isotropic, with a uniform top depth and thickness, and stable permeability and porosity; the extraction well and reinjection well in the geothermal extraction and injection project have the same extraction and reinjection layers, the same well structure and depth, and both filter pipes pass through the geothermal reservoir; the initial temperature of the geothermal reservoir is the extraction water temperature T0, and the reinjection water temperature T1 is the temperature of the filter pipe section of the reinjection well during continuous reinjection; low-temperature water mixes with high-temperature geothermal water in the geothermal reservoir and draws heat from the geothermal water in the pores and fissures of the geothermal reservoir rock, creating a temperature gradient between the migrating cold front and the reinjection well; from the leading edge of the cold front to the reinjection well, the temperature is T1 < T < T0; outside the leading edge of the cold front, the temperature is the initial temperature of the geothermal reservoir T0, unaffected by the low-temperature reinjection water; a thermal breakthrough is considered to have occurred when the cold front reaches the extraction well. Figure 2 As shown.

[0059] Derivation process:

[0060] The reinjection wellbore is the source of low temperature, T=T1. Under the drive of high head pressure, the low-temperature reinjection water moves from the reinjection wellbore outwards, forming a temperature gradient with a radius of r0. When the allowable temperature drop front (T=T0-ΔT) moves to the production well and causes a decrease in the production well temperature, it is considered a thermal breakthrough.

[0061] like Figure 3 As shown, based on the mathematical concept of differential calculus, the distance between the injection and irrigation wells is divided into countless infinitesimal equal parts. The heat loss of the annular structure with a width of dx at a distance x from the injection well (source point) on the plane is calculated, where x is the radial distance from the injection well, and dx is the annular structure with a width of dx at point x. The calculation process is as follows:

[0062] At this moment, the temperature at point dx is:

[0063] ;

[0064] In the formula, T dx The temperature at point dx is represented by dx; x represents the distance between point dx and the reinjection well, and point dx represents any point on the annulus at a distance x from the reinjection well.

[0065] The temperature drop at point dx is:

[0066] ;

[0067] Right now:

[0068] ;

[0069] In the formula, ΔT dx This represents the temperature drop at point dx.

[0070] Similarly, the heat loss at point dx is:

[0071] ;

[0072] In the formula, E lost-dx This represents the heat loss at point dx.

[0073] When the temperature of the production well drops to the allowable temperature, the heat loss from the reinjection well to the thermal reservoir column with radius dx is:

[0074] ;

[0075] Right now:

[0076] ;

[0077] In the formula:

[0078] ;

[0079] but:

[0080] ;

[0081] In the formula, E lost This represents the heat loss of a thermal storage column with a radius of dx.

[0082] When x=r0, the heat loss of the thermal reservoir is:

[0083] ;

[0084] Based on the foregoing, the heat loss E in the thermal reservoir lost E equals the heat extracted by the surface heat exchange system. used ,Right now:

[0085] ;

[0086] This leads to the following relationship between the operating time of the production-injection pair of wells and the reservoir thickness, production volume, and production-injection well distance, when the temperature of the production well is allowed to decrease by ΔT.

[0087] ;

[0088] Where t is the thermal breakthrough time of the geothermal well in the production and injection system, H is the effective thickness of the geothermal reservoir, <ρC> represents the heat capacity per unit volume of the geothermal reservoir, T0 is the water extraction temperature, T1 is the reinjection water temperature, ΔT is the allowable temperature drop, Q is the reinjection water volume, and ρ w C represents the density of the recharge water. w This refers to the specific heat capacity of the reinjection water.

[0089] Furthermore, the geothermal well extraction and irrigation data includes: effective reservoir thickness, well spacing, extraction and irrigation volume, reinjection water density, reinjection water specific heat, porosity, reservoir rock density, reservoir rock specific heat, water extraction temperature, reinjection water temperature, and allowable temperature drop.

[0090] Specifically, the basic parameters for calculating the thermal breakthrough time of the geothermal well production and irrigation system under the allowable temperature drop constraint are determined:

[0091] By combining field tests and collecting existing data from geological exploration departments and petroleum departments, based on the collected geothermal geological data such as regional stratigraphic lithology, aquifer hydraulic properties, burial characteristics, and thermal reservoir characteristics, as well as hydrodynamic and thermophysical parameters such as permeability coefficient, hydraulic conductivity, water storage coefficient, specific heat, thermal conductivity, and density, parameter values ​​are assigned to the calculation model of thermal breakthrough time of geothermal well production and irrigation system under allowable temperature drop constraints.

[0092] For example, the effective thickness H and porosity φ of the geothermal reservoir can be directly obtained from the geothermal well completion report, and the reinjection water density ρ... wSpecific heat of recharge water C w Density ρ of thermal reservoir rocks r Specific heat capacity C of geothermal reservoir rocks r It can be obtained through laboratory testing.

[0093] Calculation of thermal breakthrough time of production wells in geothermal production and irrigation systems with allowable temperature drop constraints: Based on the established calculation model of thermal breakthrough time of geothermal production and irrigation systems with allowable temperature drop constraints, the thermal breakthrough time of production wells under different production and irrigation rates, production and irrigation well spacing and allowable temperature drop conditions are directly calculated.

[0094] For example: For a typical well-to-well production and irrigation system, the effective reservoir thickness H = 120 m, the well spacing R = 400 m, and the reinjection water volume Q = 70 m³. 3 / h, recharge water density ρ w =985 kg / m 3 Specific heat of recharge water C w =4178 J / (kg·℃), porosity φ=0.3, density ρ of thermal reservoir rock r =2000 kg / m 3 Specific heat C of thermal reservoir rocks r =890 J / (kg·℃), water intake temperature T0=55℃, reinjection water temperature T1=35℃, allowable temperature drop ΔT=2℃, the thermal breakthrough time of the well is directly calculated to be 23.72 years.

[0095] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for calculating the thermal breakthrough time of a geothermal well production and irrigation system based on temperature drop constraints, characterized in that, include: Obtain geothermal well extraction and irrigation data, input the geothermal well extraction and irrigation data into the thermal breakthrough time calculation model, and obtain the thermal breakthrough time calculation results of the geothermal well extraction and irrigation system under different extraction and irrigation volumes, extraction and irrigation well spacing and allowable temperature drop conditions; The thermal breakthrough time calculation model is obtained by combining the thermal breakthrough time analysis framework based on allowable temperature drop constraints with the principle of energy conservation.

2. The method for calculating the thermal breakthrough time of a geothermal well-production and irrigation system based on temperature drop constraints according to claim 1, characterized in that, The geothermal well extraction and irrigation data include: effective reservoir thickness, well spacing, extraction and irrigation volume, reinjection water density, specific heat of reinjection water, porosity, density of reservoir rock, specific heat of reservoir rock, water extraction temperature, reinjection water temperature, and allowable temperature drop.

3. The method for calculating the thermal breakthrough time of a geothermal well-production and irrigation system based on temperature drop constraints according to claim 1, characterized in that, The thermal breakthrough time calculation model includes: Obtain the original thermal breakthrough time calculation model, and use the original thermal breakthrough time calculation model to establish the thermal breakthrough time analysis framework; The heat extracted by the surface heat exchange system is obtained, and based on the heat extracted by the surface heat exchange system, the characteristic relationship between the operating time of the production and irrigation wells and the reservoir thickness, production volume, and production-irrigation well distance is determined when the allowable temperature drop of the production well reservoir is reduced to the constraint temperature under the allowable temperature drop. Based on the aforementioned thermal breakthrough time analysis framework and the aforementioned characteristic relationships, the thermal breakthrough time calculation model is obtained.

4. The method for calculating the thermal breakthrough time of a geothermal well-production and irrigation system based on temperature drop constraints according to claim 3, characterized in that, The framework for thermal breakthrough time analysis includes: ； Where f represents the thermal breakthrough time of the geothermal well production and irrigation system, which allows for temperature drop constraints. The function is defined as follows: Q is the reinjection water volume, H is the effective thickness of the thermal reservoir, ρ is the density of the thermal reservoir, C is the specific heat capacity of the thermal reservoir, r0 represents the spacing between the production and injection wells, T0 is the water intake temperature, T1 is the reinjection water temperature, and ΔT is the allowable temperature drop.

5. The method for calculating the thermal breakthrough time of a geothermal well-production and irrigation system based on temperature drop constraints according to claim 3, characterized in that, Determining the feature relationship includes: ； Where t is the thermal breakthrough time of the geothermal well in the production and injection system, H is the effective thickness of the geothermal reservoir, <ρC> represents the heat capacity per unit volume of the geothermal reservoir, T0 is the water extraction temperature, T1 is the reinjection water temperature, ΔT is the allowable temperature drop, Q is the reinjection water volume, and ρ w C represents the density of the recharge water. w This refers to the specific heat capacity of the reinjection water.

6. The method for calculating the thermal breakthrough time of a geothermal well production and irrigation system based on temperature drop constraints according to claim 3, characterized in that, Obtaining the heat extracted by the surface heat exchange system includes: The spacing between the production and injection wells is divided into multiple equal modules. The heat loss of the target width annular body from the injection well on the plane is determined. When the temperature of the production well drops to the constrained temperature, the heat loss of the thermal storage column from the injection well to the target radius is determined based on the heat loss of the target width annular body. When the radial distance x from the injection well is x=r0, the heat loss of the thermal storage column is adjusted, and the heat extracted by the surface heat exchange system is obtained using the adjusted heat loss of the thermal storage column.

7. The method for calculating the thermal breakthrough time of a geothermal well-production and irrigation system based on temperature drop constraints according to claim 6, characterized in that, The heat loss from the reinjection well to the target radius of the thermal reservoir includes: ； Among them, E lost ρC represents the heat loss of the reservoir column with radius x, H represents the effective thickness of the reservoir, <ρC> represents the heat capacity per unit volume of the reservoir, T0 represents the water intake temperature, T1 represents the reinjection water temperature, x represents the distance to the reinjection well, r0 represents the distance between the production and injection wells, and ΔT represents the allowable temperature drop.

8. The method for calculating the thermal breakthrough time of a geothermal well production and irrigation system based on temperature drop constraints according to claim 6, characterized in that, Adjusting the heat loss of the heat storage column includes: ； Among them, E lost The adjusted heat loss of the reservoir column is represented by r0, which indicates the distance between the production and injection wells, H is the effective thickness of the reservoir, <ρC> represents the heat capacity per unit volume of the reservoir, T0 is the water intake temperature, T1 is the reinjection water temperature, and ΔT is the allowable temperature drop.

9. The method for calculating the thermal breakthrough time of a geothermal well production and irrigation system based on temperature drop constraints according to claim 6, characterized in that, Obtaining the heat extracted by the surface heat exchange system includes: ； Where Q is the reinjection water volume, t is the thermal breakthrough time of the geothermal well for the well-injection system, and ρ w C represents the density of the recharge water. w The specific heat capacity of the reinjection water is given by <ρC>, which represents the heat capacity per unit volume of the thermal reservoir. T0 is the water intake temperature, T1 is the reinjection water temperature, r0 is the distance between the production and injection wells, H is the effective thickness of the thermal reservoir, and ΔT is the allowable temperature drop.

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