Method for calculating sustainable mining quantity in mining stage of geothermal field

Abstract

The invention discloses a geothermal field mining stage sustainable mining quantity calculation method, and belongs to the technical field of data processing, and the method comprises the steps: constructing a hydrothermal coupling numerical model of a regional geothermal field, calculating the thermal breakthrough time of a geothermal mining well in the geothermal field according to the model, and obtaining the sustainable mining quantity under the current situation of the geothermal field based on the thermal breakthrough time; a newly-added mining area meeting the mining conditions is selected, and geothermal mining wells are arranged in the newly-added mining area; the sustainable exploitation quantity of the geothermal exploitation well in the newly-added area is calculated, and the remaining sustainable exploitation quantity is obtained; and obtaining the sustainable mining quantity of the geothermal field mining stage based on the sustainable mining quantity and the residual sustainable mining quantity under the current situation of the geothermal field. According to the method, the sustainable exploitation quantity is calculated under the current condition, the remaining sustainable exploitation quantity is calculated according to the suitable exploitation area, the geothermal fluid sustainable exploitation quantity can be re-evaluated according to the problems occurring in geothermal exploitation, and the requirement of geothermal resource management is better met.

Description

Technical Field

[0001] The invention belongs to the technical field of data processing, and in particular relates to a method for calculating the sustainable extraction volume in a geothermal field extraction stage. Background Art

[0002] Geothermal energy is a renewable clean energy with huge development potential. In recent years, with the development of social economy, energy is becoming increasingly scarce and environmental problems are becoming increasingly serious. Geothermal energy has gradually attracted people's attention, setting off a round of geothermal development climax. Currently, the available geothermal resources mainly include shallow geothermal energy, medium and deep geothermal energy and hot dry rocks. According to their properties, geothermal resources can be divided into static reserves of geothermal resources and exploitable geothermal resources. Among them, static reserves are the amount of geothermal resources objectively existing in the heat reserve, and the exploitable amount is the amount of resources that can be exploited in the static reserves in the short term. At present, the focus of estimation is the exploitable amount of geothermal resources, and the calculation methods mainly include analytical method, numerical method, analogy method and thermal storage method. However, for geothermal fields that have been exploited on a large scale, combined with the problems encountered in exploitation and the needs of geothermal resource management, the exploitable amount of geothermal resources should be re-evaluated. The principles and accuracy of existing calculation methods are difficult to achieve the purpose of calculating sustainable exploitation in the exploitation stage of geothermal fields. Summary of the invention

[0003] In order to solve the above technical problems, the present invention proposes a method for calculating the sustainable extraction volume in the exploitation stage of a geothermal field to solve the above problems existing in the prior art.

[0004] To achieve the above object, the present invention provides a method for calculating the sustainable extraction volume in the exploitation stage of a geothermal field, comprising:

[0005] Construct a hydrothermal coupling numerical model of the regional geothermal field, calculate the thermal breakthrough time of the geothermal production wells in the geothermal field based on the hydrothermal coupling numerical model of the regional geothermal field, and obtain the sustainable production volume under the current conditions of the geothermal field based on the thermal breakthrough time;

[0006] Selecting a new mining area that meets the mining conditions, and laying geothermal mining wells in the new mining area; calculating the sustainable mining volume of the geothermal mining wells in the new mining area to obtain the remaining sustainable mining volume;

[0007] Based on the sustainable extraction volume and the remaining sustainable extraction volume under the current conditions of the geothermal field, the sustainable extraction volume in the geothermal field extraction stage is obtained.

[0008] Optionally, the process of constructing a hydrothermal coupled numerical model of a regional geothermal field includes:

[0009] Obtain the geological data of the geothermal field to be calculated and the dynamic monitoring data of geothermal production wells; analyze the geological data and the dynamic monitoring data of geothermal production wells to obtain the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the supply and migration characteristics of geothermal fluids; construct a hydrothermal coupling numerical model of the regional geothermal field based on the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the supply and migration characteristics of geothermal fluids.

[0010] Optionally, the geological data includes regional data and parameter data, the regional data includes regional geological data, hydrogeological data, and geothermal geological data; the parameter data includes hydrogeological parameter data and thermophysical parameters.

[0011] Optionally, the process of obtaining the sustainable extraction amount of the geothermal field under the current conditions based on the thermal breakthrough time includes:

[0012] Obtain the number of existing geothermal production wells in the geothermal field and the key thermodynamic parameters of each geothermal production well; calculate the sustainable production volume under the current conditions of the geothermal field based on the number of existing geothermal production wells and the key thermodynamic parameters; wherein the key thermodynamic parameters include: the amount of recoverable hot water, the outlet water temperature, the reinjection water temperature, the specific heat capacity of geothermal water corresponding to the outlet water temperature, and the geothermal water density corresponding to the outlet water temperature.

[0013] Optionally, the process of obtaining the recoverable water volume of each geothermal production well includes:

[0014] The annual average production and total actual production of geothermal wells before the survey base year are obtained, including the survey base year. The estimated recoverable production after the survey base year is calculated based on the annual average production. The recoverable water volume is obtained based on the total actual production and the estimated recoverable production after the survey base year.

[0015] Optionally, the process of laying out geothermal production wells in the newly added production area includes:

[0016] Remote sensing image data of geothermal fields are acquired, distribution information of concentrated residential areas is obtained based on the remote sensing image data of geothermal fields, and geothermal production wells are arranged based on the distribution information, wherein the geothermal production wells meet the condition of not generating thermal breakthrough within a preset time.

[0017] Optionally, the process of obtaining a residual sustainable extraction volume includes:

[0018] Based on the average water output, average specific heat capacity, average density and average water output temperature of the existing geothermal production wells in the geothermal field, combined with the number of geothermal production wells in the newly added production area, the remaining sustainable production volume is obtained.

[0019] The present invention also provides a computer device, which includes a memory and a processor connected to the memory; the memory is used to store computer programs; the processor is used to run the computer programs stored in the memory to execute the steps of the above-mentioned method for calculating sustainable extraction volume in the geothermal field extraction stage.

[0020] The present invention also provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for calculating the sustainable extraction amount in the geothermal field extraction stage are implemented.

[0021] Compared with the prior art, the present invention has the following advantages and technical effects:

[0022] The present invention first obtains geological data of a geothermal field to be calculated and dynamic monitoring data of geothermal production wells, and constructs a hydrothermal coupling numerical model of a regional geothermal field according to the obtained data; then, based on the hydrothermal coupling numerical model of the regional geothermal field, the thermal breakthrough time of the geothermal production wells in the geothermal field is calculated, and the sustainable production volume under the current conditions of the geothermal field is obtained based on the thermal breakthrough time; then, a new production area that meets the production conditions is selected, and geothermal production wells are arranged in the new production area; the sustainable production volume of the geothermal production wells in the new production area is calculated to obtain the remaining sustainable production volume; finally, based on the sustainable production volume under the current conditions of the geothermal field and the remaining sustainable production volume, the sustainable production volume of the geothermal field in the production stage is obtained.

[0023] The present invention is aimed at geothermal fields that have been exploited on a large scale. Based on the current status of geothermal resource development and utilization, the sustainable exploitation amount under the current conditions and the remaining sustainable exploitation amount are calculated separately to obtain the sustainable exploitation amount of the geothermal field exploitation stage. Compared with the previous geothermal resource calculation method, for geothermal fields that have been exploited on a large scale, the present invention realizes the calculation of the sustainable exploitation amount under the current conditions, and calculates the remaining sustainable exploitation amount based on the suitable exploitation area. It can re-evaluate the sustainable exploitation amount of geothermal fluids in response to problems arising in geothermal exploitation, which is more in line with the needs of geothermal resource management. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0025] Figure 1 The figure is a flow chart of a method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0028] Embodiment 1

[0029] The number of geothermal wells and the amount of production in a geothermal field in a certain area have increased year by year, resulting in a rapid drop in the water level of the geothermal reservoir in the region. Subsequently, reinjection wells were added to the existing production wells, so that the water level of the geothermal reservoir in the geothermal field no longer dropped and tended to be stable. On this basis, the sustainable production of the geothermal field needs to be calculated later.

[0030] like Figure 1 As shown, this embodiment provides a method for calculating the sustainable extraction volume in the geothermal field extraction stage, including:

[0031] Construct a hydrothermal coupling numerical model of the regional geothermal field, calculate the thermal breakthrough time of the geothermal production wells in the geothermal field based on the hydrothermal coupling numerical model of the regional geothermal field, and obtain the sustainable production volume under the current conditions of the geothermal field based on the thermal breakthrough time;

[0032] In some embodiments, the process of constructing a hydrothermal coupled numerical model of a regional geothermal field includes:

[0033] Obtain the geological data of the geothermal field to be calculated and the dynamic monitoring data of geothermal production wells; analyze the geological data and the dynamic monitoring data of geothermal production wells to obtain the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the supply and migration characteristics of geothermal fluids; construct a hydrothermal coupling numerical model of the regional geothermal field based on the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the supply and migration characteristics of geothermal fluids.

[0034] In some embodiments, the geological data includes regional data and parameter data, the regional data includes regional geological data, hydrogeological data, geothermal geological data; the parameter data includes hydrogeological parameter data and thermophysical parameters.

[0035] Specifically, the regional geological data, hydrogeological data, geothermal geological data, hydrogeological parameters and thermophysical parameter data of the selected geothermal field are obtained, and the historical dynamic monitoring data of the existing geothermal exploitation wells in the geothermal field are obtained. By analyzing the above geological data, parameter data and dynamic monitoring data, the geothermal well parameters such as the location, depth and temperature of the existing geothermal wells in the geothermal field and the heat storage parameters such as the heat storage area, top and bottom plate depth, heat storage temperature, as well as the internal and external boundary conditions of the geothermal field and the supply and migration characteristics of the geothermal fluid can be basically determined.

[0036] Illustratively, regional geological data include regional stratigraphic lithology, geological structure, etc., hydrogeological data include hydraulic properties, burial characteristics and chemical characteristics of aquifers, geothermal geological data include regional geothermal field characteristics and heat storage characteristics, etc.; key hydrogeological parameters include permeability coefficient, hydraulic conductivity, water storage coefficient, etc.; thermophysical parameters include specific heat, thermal conductivity, density, thermal diffusivity and rock heat generation rate, etc.; dynamic monitoring data include geothermal water level, extraction volume, reinjection volume, water quality and geothermal field under large-scale extraction and irrigation conditions of geothermal fields.

[0037] The above regional data, parameter data and dynamic monitoring data are obtained from existing geological and mining exploration departments and petroleum departments.

[0038] In some embodiments, the process of obtaining the sustainable production volume of the geothermal field under the current conditions based on the thermal breakthrough time includes:

[0039] Obtain the number of existing geothermal production wells in the geothermal field and the key thermodynamic parameters of each geothermal production well; calculate the sustainable production volume under the current conditions of the geothermal field based on the number of existing geothermal production wells and the key thermodynamic parameters; wherein the key thermodynamic parameters include: the amount of recoverable hot water, the outlet water temperature, the reinjection water temperature, the specific heat capacity of geothermal water corresponding to the outlet water temperature, and the geothermal water density corresponding to the outlet water temperature.

[0040] Specifically, the sustainable extraction volume under current conditions is calculated based on the existing geothermal extraction and injection well layout and extraction and injection volume of the geothermal field. The calculation formula can be expressed as:

[0041] ;

[0042] Where: W 现 represents the sustainable extraction volume under the current conditions, with the unit of J; i represents the i-th existing geothermal extraction well in the geothermal field, and m represents the total number of existing geothermal extraction wells in the geothermal field; Q i is the recoverable geothermal water volume of the i-th existing geothermal exploitation well in the geothermal field, that is, the recoverable hot water volume before the exploitation well in the geothermal field numerical model produces thermal breakthrough (if no thermal breakthrough occurs within 100 years, 100 years is taken), unit is m 3 ; T i is the outlet water temperature of the ith geothermal well, in °C; T in is the recharging water temperature, in °C; c i is the specific heat capacity of geothermal water corresponding to the outlet water temperature of the i-th existing geothermal exploitation well in the geothermal field, in J / (kg / ℃); ρ i is the geothermal water density corresponding to the outlet water temperature of the i-th existing geothermal exploitation well in the geothermal field, in kg / m 3 .

[0043] Among them, the geothermal fields already have geothermal extraction well layout and extraction and injection volume, including all operating and closed geothermal wells in the geothermal fields in the survey base year and before, and all extraction volumes generated by them.

[0044] In some embodiments, the process of obtaining the amount of recoverable water in each geothermal production well includes:

[0045] The annual average production and total actual production of geothermal wells before the survey base year are obtained, including the survey base year. The estimated recoverable production after the survey base year is calculated based on the annual average production. The recoverable water volume is obtained based on the total actual production and the estimated recoverable production after the survey base year.

[0046] Specifically, the production volume of existing geothermal wells is the sum of the total actual production volume in and before the survey base year and the total expected production volume after the survey base year until the thermal breakthrough of the wells, which can be expressed by the following calculation formula:

[0047] ;

[0048] Where: q i,j It represents the actual production volume of the i-th existing geothermal well in the geothermal field in the j-th year (before the survey base year), in m 3 ; a i is the total number of years from the start of mining of the i-th existing geothermal well to the survey base year; It represents the average annual production of the i-th existing geothermal well in the geothermal field before the survey base year, in m 3 ; b i It is the total number of years from the start of production of the i-th existing geothermal well to the occurrence of thermal breakthrough.

[0049] Among them, the thermal breakthrough time of a geothermal well is the time corresponding to a 1 degree Celsius drop in the water temperature of the exploitation well. If the water temperature of the exploitation well does not experience a thermal breakthrough for 100 years, 100 years is taken.

[0050] According to the calculation, the thermal breakthrough time and sustainable production volume W of the existing geothermal wells in a geothermal field under the current conditions are obtained. 现 =3.34×10 16 J, as shown in Table 1. The “ / ” in the table indicates that no thermal breakthrough occurred after 100 years of continuous mining.

[0051] Table 1

[0052]

[0053] Selecting a new mining area that meets the mining conditions, and laying geothermal mining wells in the new mining area; calculating the sustainable mining volume of the geothermal mining wells in the new mining area to obtain the remaining sustainable mining volume;

[0054] In some embodiments, the process of deploying geothermal production wells in the newly added production area includes:

[0055] Remote sensing image data of geothermal fields are acquired, distribution information of concentrated residential areas is obtained based on the remote sensing image data of geothermal fields, and geothermal production wells are arranged based on the distribution information, wherein the geothermal production wells meet the condition of not generating thermal breakthrough within a preset time.

[0056] Specifically, the thermal breakthrough time of a geothermal well is the time corresponding to a 1 degree Celsius drop in the water temperature of the production well. If the water temperature of the production well does not experience a thermal breakthrough for 100 years, 100 years is taken.

[0057] Calculate the suitable mining areas for the remaining sustainable mining volume, select concentrated residential areas such as communities and towns with development and utilization value in the area for concentrated layout of geothermal mining and irrigation wells; determine the location and distribution of concentrated residential areas such as communities and towns in the geothermal field based on remote sensing image data; the design of the geothermal mining and irrigation wells must meet the condition that the mining wells will not produce thermal breakthroughs after 100 years of system operation; the total heat that can be extracted from the newly laid geothermal mining and irrigation wells after 100 years of operation is the remaining sustainable mining volume.

[0058] In some embodiments, the process of obtaining the remaining sustainable yield comprises:

[0059] Based on the average water output, average specific heat capacity, average density and average water output temperature of the existing geothermal production wells in the geothermal field, combined with the number of geothermal production wells in the newly added production area, the remaining sustainable production volume is obtained.

[0060] Specifically, the remaining sustainable extraction volume in the geothermal field extraction stage is calculated, and the calculation formula can be expressed as:

[0061] ;

[0062] Where: W 余 is the remaining sustainable extraction volume, in J; n is the total number of newly added geothermal extraction wells in the geothermal field; Q is the average water output of existing geothermal extraction wells in the geothermal field, in m 3 ; c is the specific heat of geothermal water, which is determined by the average outlet water temperature of the geothermal field wells, and the unit is J / (kg / ℃); ρ is the density of geothermal water, which is determined by the average outlet water temperature of the geothermal field wells, and the unit is kg / m 3 ; T is the average outlet water temperature of the geothermal field production wells, in °C.

[0063] For example, we selected communities, towns and other concentrated residential areas in the region to lay geothermal wells, with a total of 162 mining wells and 162 reinjection wells. The remaining sustainable mining volume of the geothermal field W is calculated. 余 =3.46×10 17 J.

[0064] Based on the sustainable extraction volume and the remaining sustainable extraction volume under the current conditions of the geothermal field, the sustainable extraction volume in the geothermal field extraction stage is obtained.

[0065] Specifically, the calculation formula for the sustainable extraction volume in the geothermal field exploitation stage can be expressed as:

[0066] ;

[0067] Where: W 可 is the sustainable extraction volume of geothermal field in the mining stage, in J; W 现 W is the sustainable mining volume under current conditions, in J; 余 is the remaining sustainable mining volume, in J.

[0068] For example, the sustainable extraction volume of a geothermal field is the sum of the sustainable extraction volume under the current conditions and the remaining sustainable extraction volume. The sustainable extraction volume W of a geothermal field is calculated according to 可 =3.79×10 17 J.

[0069] The present invention also provides a computer device, which includes a memory and a processor connected to the memory; the memory is used to store computer programs; the processor is used to run the computer programs stored in the memory to execute the steps of the above-mentioned method for calculating sustainable extraction volume in the geothermal field extraction stage.

[0070] The present invention also provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for calculating the sustainable extraction amount in the geothermal field extraction stage are implemented.

[0071] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for calculating the sustainable extraction volume in the exploitation stage of a geothermal field, characterized in that: The following steps are involved: Construct a hydrothermal coupling numerical model of the regional geothermal field, calculate the thermal breakthrough time of the geothermal production wells in the geothermal field based on the hydrothermal coupling numerical model of the regional geothermal field, and obtain the sustainable production volume under the current conditions of the geothermal field based on the thermal breakthrough time; Selecting a new mining area that meets the mining conditions, and laying geothermal mining wells in the new mining area; Calculate the sustainable production volume of geothermal wells in the newly added production area to obtain the remaining sustainable production volume; Based on the sustainable extraction volume and the remaining sustainable extraction volume under the current conditions of the geothermal field, the sustainable extraction volume in the geothermal field extraction stage is obtained.

2. The method for calculating the sustainable extraction volume in the geothermal field extraction stage according to claim 1 is characterized in that: The process of constructing a hydrothermal coupled numerical model of a regional geothermal field includes: Obtain the geological data of the geothermal field to be calculated and the dynamic monitoring data of geothermal production wells; analyze the geological data and the dynamic monitoring data of geothermal production wells to obtain the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the supply and migration characteristics of geothermal fluids; construct a hydrothermal coupling numerical model of the regional geothermal field based on the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the supply and migration characteristics of geothermal fluids.

3. The method for calculating the sustainable extraction volume in the geothermal field extraction stage according to claim 2 is characterized in that: The geological data include regional data and parameter data. The regional data include regional geological data, hydrogeological data, and geothermal geological data; the parameter data include hydrogeological parameter data and thermophysical parameters.

4. The method for calculating the sustainable extraction volume in the geothermal field extraction stage according to claim 1 is characterized in that: The process of obtaining the sustainable extraction volume of geothermal fields under the current conditions based on the thermal breakthrough time includes: Obtain the number of existing geothermal production wells in the geothermal field and the key thermodynamic parameters of each geothermal production well; calculate the sustainable production volume under the current conditions of the geothermal field based on the number of existing geothermal production wells and the key thermodynamic parameters; wherein the key thermodynamic parameters include: the amount of recoverable hot water, the outlet water temperature, the reinjection water temperature, the specific heat capacity of geothermal water corresponding to the outlet water temperature, and the geothermal water density corresponding to the outlet water temperature.

5. The method for calculating the sustainable extraction volume in the geothermal field extraction stage according to claim 4 is characterized in that: The process of obtaining the recoverable water volume of each geothermal well includes: The annual average production and total actual production of geothermal wells before the survey base year are obtained, including the survey base year. The estimated recoverable production after the survey base year is calculated based on the annual average production. The recoverable water volume is obtained based on the total actual production and the estimated recoverable production after the survey base year.

6. The method for calculating the sustainable extraction volume in the geothermal field extraction stage according to claim 1, characterized in that: The process of laying out geothermal production wells in the newly added production area includes: Remote sensing image data of geothermal fields are acquired, distribution information of concentrated residential areas is obtained based on the remote sensing image data of geothermal fields, and geothermal production wells are arranged based on the distribution information, wherein the geothermal production wells meet the condition of not generating thermal breakthrough within a preset time.

7. The method for calculating the sustainable extraction volume in the geothermal field extraction stage according to claim 1, characterized in that: The process of achieving a sustainable residual includes: Based on the average water output, average specific heat capacity, average density and average water output temperature of the existing geothermal production wells in the geothermal field, combined with the number of geothermal production wells in the newly added production area, the remaining sustainable production volume is obtained.

8. A computer device, characterized in that: The computer device includes a memory and a processor connected to the memory; the memory is used to store computer programs; the processor is used to run the computer programs stored in the memory to execute the steps of the method for calculating the sustainable extraction volume in the geothermal field extraction stage as described in any one of claims 1-7.

9. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the computer program implements the steps of the method for calculating the sustainable extraction volume in the exploitation stage of a geothermal field as claimed in any one of claims 1 to 7.

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