A method for calculating sustainable extraction volume in geothermal field mining stage

Abstract

The present invention discloses a method for calculating the sustainable extraction amount in the exploitation stage of a geothermal field, which belongs to the field of data processing technology, and includes: constructing a hydrothermal coupling numerical model of a regional geothermal field, calculating the thermal breakthrough time of a geothermal extraction well in the geothermal field according to the model, and obtaining the sustainable extraction amount under the current conditions of the geothermal field based on the thermal breakthrough time; selecting a new exploitation area that meets the exploitation conditions, and laying out geothermal extraction wells in the new exploitation area; calculating the sustainable extraction amount of the geothermal extraction wells in the new exploitation area to obtain the remaining sustainable extraction amount; and obtaining the sustainable extraction amount in the exploitation stage of the geothermal field based on the sustainable extraction amount under the current conditions of the geothermal field and the remaining sustainable extraction amount. The present invention realizes the calculation of the sustainable extraction amount under the current conditions, and calculates the remaining sustainable extraction amount based on the suitable exploitation area, and can re-evaluate the sustainable extraction amount of geothermal fluids in response to problems arising in geothermal exploitation, which is more in line with the needs of geothermal resource management.

Description

Technical Field

[0001] The present invention belongs to the technical field of data processing, and particularly relates to a method for calculating the sustainable exploitation volume during the exploitation stage of a geothermal field. Background Art

[0002] Geothermal energy is a renewable clean energy with great development potential. In recent years, with the development of social economy, energy has become increasingly tense and environmental problems have become increasingly serious. Geothermal energy has gradually attracted people's attention and set off a wave of geothermal development. Currently, the available geothermal resources mainly include shallow geothermal energy, medium-deep geothermal energy, and hot dry rock. Geothermal resources can be divided into geothermal resource static reserves and geothermal resource exploitable volume according to their properties. Among them, the static reserves are the geothermal resources objectively existing in the reservoir, and the exploitable volume is the resources that can be exploited in the short term in the static reserves. At present, the focus of estimation is on the geothermal resource exploitable volume, and the calculation methods mainly include the analytical method, the numerical method, the analogy method, and the reservoir method. However, for geothermal fields where geothermal resources have been exploited on a large scale, in combination with the problems that occur during exploitation and the needs of geothermal resource management, the exploitable volume of geothermal resources should be re-evaluated, and the principles and accuracies of existing calculation methods are difficult to achieve the purpose of calculating the sustainable exploitation volume during the exploitation stage of the geothermal field. Summary of the Invention

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

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

[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 exploitation volume under the current conditions of the geothermal field based on the thermal breakthrough time;

[0006] Select a new exploitation area that meets the exploitation conditions, and arrange geothermal production wells in the new exploitation area; calculate the sustainable exploitation volume of the geothermal production wells in the new area to obtain the remaining sustainable exploitation volume;

[0007] Obtain the sustainable exploitation volume during the exploitation stage of the geothermal field based on the sustainable exploitation volume under the current conditions of the geothermal field and the remaining sustainable exploitation volume.

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

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

[0011] Optionally, the process of obtaining the sustainable production volume under the current conditions of the geothermal field based on the heat 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: exploitable hot water volume, water outlet temperature, reinjection water temperature, specific heat capacity of geothermal water corresponding to the water outlet temperature, and density of geothermal water corresponding to the water outlet temperature.

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

[0014] Obtain the annual average production volume and total actual production volume of the geothermal production well before and including the investigation reference year, and calculate the estimated exploitable volume after the investigation reference year based on the annual average production volume; obtain the exploitable water volume based on the total actual production volume and the estimated exploitable volume after the investigation reference year.

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

[0016] Obtain the remote sensing image data of the geothermal field, obtain the distribution information of concentrated residential areas based on the remote sensing image data of the geothermal field, and arrange geothermal production wells based on the distribution information, and the geothermal production wells meet the condition of not generating heat breakthrough within a preset time.

[0017] Optionally, the process of obtaining the remaining sustainable production volume includes:

[0018] Based on the average water production volume, average specific heat capacity, average density, and average water outlet temperature of the existing geothermal production wells in the geothermal field, and combining with the number of geothermal production wells in the newly added exploitation area, obtain the remaining sustainable production volume.

[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 a computer program; the processor is used to run the computer program stored in the memory to execute the steps of the above-mentioned calculation method for the sustainable extraction volume in the geothermal field exploitation stage.

[0020] The present invention also provides a storage medium, which stores a computer program, and the computer program realizes the steps of the above-mentioned calculation method for the sustainable extraction volume in the geothermal field exploitation stage when executed by a processor.

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

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

[0023] For the geothermal field that has been exploited on a large scale, the present invention calculates the sustainable extraction volume under the current conditions and the remaining sustainable extraction volume respectively on the basis of the current situation of the development and utilization of geothermal resources, and obtains the sustainable extraction volume in the geothermal field exploitation stage. Compared with the previous calculation methods for geothermal resources, for the geothermal field where geothermal resources have been exploited on a large scale, the present invention realizes the calculation of the sustainable extraction volume under the current conditions, and calculates the remaining sustainable extraction volume based on the suitable exploitation area, and can re-evaluate the sustainable extraction volume of geothermal fluid in response to the problems that occur in geothermal exploitation, which better meets the needs of geothermal resource management. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0025] Figure 1 is the flowchart of the method of the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[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; 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 the geothermal wells; analyze the geological data and the dynamic monitoring data of the geothermal wells to obtain the geothermal well parameters, heat storage parameters, boundary conditions of the geothermal field, and the replenishment and migration characteristics of the geothermal fluid; 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 replenishment and migration characteristics of the geothermal fluid; 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 hot water that can be produced, the outlet water temperature, the reinjection water temperature, the specific heat capacity of the geothermal water corresponding to the outlet water temperature, and the geothermal water density corresponding to the outlet water temperature; The process of obtaining the amount of recoverable hot water from each geothermal well includes: Obtain the average annual production and total actual production of geothermal wells before and including the survey base year, and calculate the estimated recoverable production after the survey base year based on the average annual production; obtain the recoverable hot water volume based on the total actual production and the estimated recoverable production after the survey base year; Thermal breakthrough time is the time corresponding to a 1 degree Celsius drop in the water temperature of the production well; 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; The process of laying out geothermal production wells in the newly added production area includes: Acquire remote sensing image data of geothermal fields, obtain distribution information of concentrated residential areas based on the remote sensing image data of geothermal fields, and arrange geothermal exploitation wells based on the distribution information, wherein the geothermal exploitation wells meet the condition that no thermal breakthrough occurs within a preset time; The process of obtaining the remaining sustainable extraction volume includes: According to the average water output, average specific heat capacity, average density and average water output temperature of the existing geothermal mining wells in the geothermal field, combined with the number of geothermal mining wells in the newly added mining area, the remaining sustainable mining volume is obtained; 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 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.

3. 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 1-2.

4. 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 2.

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