CN-122021432-A - Fracture geothermal reservoir water quality evolution simulation method and system based on water-rock reaction

CN122021432ACN 122021432 ACN122021432 ACN 122021432ACN-122021432-A

Abstract

The invention belongs to the technical field of crack type thermal water storage quality evolution, and provides a crack type geothermal reservoir water quality evolution simulation method and system based on water-rock reaction, wherein the method comprises the steps of obtaining a mixed dimension geometric model of a crack type thermal reservoir; the method comprises the steps of obtaining a mixed dimension geometrical model, constructing a fracture medium seepage-heat transfer-solute reaction migration control equation based on the obtained mixed dimension geometrical model, coupling the constructed fracture medium seepage-heat transfer-solute reaction migration control equation according to a chemical reaction system of a fracture thermal reservoir geothermal fluid to obtain a seepage-heat transfer-solute reaction migration multi-field coupling model, solving the obtained seepage-heat transfer-solute reaction migration multi-field coupling model, simulating the evolution of a temperature field, a seepage field and a chemical field in the geothermal exploitation process according to a solving result, and completing the fracture geothermal reservoir water quality evolution simulation based on a water rock reaction.

Inventors

DONG JIE
CHEN TAO
WANG RUJIE
Gong Huijin
HE PENG
LIU HAOLIN
FU JIANI
Xiao Zhengxu

Assignees

青岛地质工程勘察院(青岛地质勘查开发局)
山东科技大学

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (10)

1. The fracture geothermal reservoir water quality evolution simulation method based on the water-rock reaction is characterized by comprising the following steps of: Acquiring a mixed dimension geometric model of a fracture type thermal reservoir; constructing a fracture medium seepage-heat transfer-solute reaction migration control equation based on the acquired mixed dimension geometric model; According to a chemical reaction system of the geothermal fluid of the fracture type thermal reservoir, coupling the constructed fracture medium seepage-heat transfer-solute reaction migration control equation to obtain a seepage-heat transfer-solute reaction migration multi-field coupling model; And solving the obtained seepage-heat transfer-solute reaction migration multi-field coupling model, and simulating the evolution of a temperature field, a seepage field and a chemical field in the geothermal exploitation process according to the solving result to finish the water quality evolution simulation of the fracture geothermal reservoir based on the water-rock reaction.
2. The water rock reaction-based fracture geothermal reservoir water quality evolution simulation method according to claim 1, wherein the constructed fracture medium seepage-heat transfer-solute reaction migration control equation is subjected to multi-field coupling, and a seepage-heat transfer-solute reaction migration multi-field coupling model is obtained through real-time transmission of state variables and a dynamic update of physical parameters by a bidirectional feedback mechanism.
3. The method for simulating water quality evolution of a fracture geothermal reservoir based on a water-rock reaction as claimed in claim 1, wherein the constructed fracture medium seepage-heat transfer-solute reaction migration control equation comprises a fracture medium seepage equation, a heat transfer control equation and a reactive solute migration equation.
4. A method for simulating the evolution of water quality in a fracture-type geothermal reservoir based on a water-rock reaction as claimed in claim 3, wherein the sequential iterative method is adopted to solve the constructed fracture medium seepage-heat transfer-solute reaction migration control equation, and the steps in one time step are as follows: based on the temperature and the porosity at the last moment, the physical properties of the fluid and the thermal reservoir are updated, and a seepage equation is solved to obtain grid pressure and Darcy flow rate; based on the obtained Darcy flow rate, solving a heat transfer equation, and updating the grid temperature; solving a solute transport equation by using the updated Darcy flow rate to obtain a primary concentration; calling a chemical thermodynamic module, and carrying out chemical equilibrium calculation on each grid by taking the current temperature and the primary concentration as input to obtain the mineral dissolution/precipitation amount and the balanced real concentration; and updating the porosity according to the mineral dissolution/precipitation amount, and updating the permeability as input of the next time step, so as to complete the solution of the fracture medium seepage-heat transfer-solute reaction migration control equation.
5. The water rock reaction-based fracture geothermal reservoir water quality evolution simulation method according to claim 1, wherein fracture geometric characteristics at least comprising length, gap width, inclination and inclination angle are obtained before a mixed dimensional geometric model is obtained, and a mixed dimensional mesh subdivision technology is adopted to enable nodes of a three-dimensional unit bedrock mesh and a two-dimensional unit fracture mesh to coincide at a contact interface, so that the mixed dimensional geometric model at least comprising the three-dimensional bedrock geometric model and the two-dimensional fracture geometric model is obtained.
6. The method for simulating water quality evolution of a fracture geothermal reservoir based on water-rock reaction as claimed in claim 1, wherein water chemistry analysis data of geothermal fluid is obtained, chemical components and mineral phases of geothermal fluid are determined according to ion composition and concentration in the water chemistry analysis data, a chemical reaction system of geothermal fluid is constructed, and a chemical thermodynamic equilibrium solver for calculating equilibrium state of chemical system under specific temperature and pressure conditions is obtained based on the constructed chemical reaction system.
7. The utility model provides a fracture geothermal reservoir water quality evolution analog system based on water rock reaction which characterized in that includes: an acquisition module configured to acquire a mixed dimensional geometric model of a fracture thermal reservoir; a construction module configured to construct a fracture medium seepage-heat transfer-solute reaction migration control equation based on the acquired mixed-dimension geometric model; The coupling module is configured to couple the constructed fracture medium seepage-heat transfer-solute reaction migration control equation according to a chemical reaction system of the geothermal fluid of the fracture thermal reservoir to obtain a seepage-heat transfer-solute reaction migration multi-field coupling model; The simulation module is configured to solve the obtained seepage-heat transfer-solute reaction migration multi-field coupling model, simulate the evolution of a temperature field, a seepage field and a chemical field in the geothermal exploitation process according to the solving result, and complete the fracture geothermal reservoir water quality evolution simulation based on the water-rock reaction.
8. A computer readable storage medium having stored thereon a computer program, which when executed by a processor, implements the steps of the water rock reaction based fracture geothermal reservoir water quality evolution simulation method of any one of claims 1-6.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and running on the processor, characterized in that the processor implements the steps of the water rock reaction based fracture geothermal reservoir water quality evolution simulation method according to any one of claims 1-6 when the program is executed.
10. A computer program product comprising software code, characterized in that a program in said software code performs the steps of the method for simulating the evolution of water quality in a fracture geothermal reservoir based on a water-rock reaction according to any one of claims 1-6.

Description

Fracture geothermal reservoir water quality evolution simulation method and system based on water-rock reaction Technical Field The invention belongs to the technical field of fracture thermal water storage quality evolution, and particularly relates to a fracture geothermal reservoir water quality evolution simulation method and system based on water-rock reaction. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. The geothermal energy is used as a renewable, clean and stable energy source and has important development and utilization values. The fracture type heat storage is a geothermal reservoir type which is widely distributed and has important application prospect, and the fracture network is used as a main channel for fluid seepage and heat migration, so that the fracture type heat storage has a key effect on the efficient development of geothermal resources. In the geothermal exploitation process, the water quality characteristics of geothermal fluid are related to sustainable utilization of resources, and the operation safety of a mining and irrigation system, such as pipeline scaling, equipment corrosion and the like, are directly affected. Therefore, the method accurately predicts the water quality evolution law in the geothermal exploitation process, and has important significance for scientific management and sustainable development of geothermal resources. At present, the fracture type thermal storage numerical simulation technology has greatly progressed, and is mainly focused on the aspects of temperature field and seepage field coupling simulation and the like. However, in the prior art, when facing to fracture type hot water storage evolution simulation, the technology has the technical bottlenecks that most simulation software only considers the coupling of two fields of hot water and water in the chemical process coupling level, lacks effective characterization of the chemical reaction process of water and rock, cannot simulate key chemical processes such as mineral dissolution precipitation, ion concentration change and the like, the traditional reactive solute migration model mainly aims at pore media in the fracture-chemical coupling level, is difficult to process complex geometric topological structures and multidimensional flow characteristics in the fracture media, and lacks effective multi-well water quality monitoring and predicting means in the engineering application level, so that quantitative basis is difficult to be provided for geothermal exploitation scheme optimization and structural risk early warning. Disclosure of Invention In order to solve the problems, the invention provides a fracture geothermal reservoir water quality evolution simulation method and a fracture geothermal reservoir water quality evolution simulation system based on water rock reaction. According to some embodiments, the first scheme of the invention provides a fracture geothermal reservoir water quality evolution simulation method based on water-rock reaction, which adopts the following technical scheme: a fracture geothermal reservoir water quality evolution simulation method based on water-rock reaction comprises the following steps: Acquiring a mixed dimension geometric model of a fracture type thermal reservoir; constructing a fracture medium seepage-heat transfer-solute reaction migration control equation based on the acquired mixed dimension geometric model; According to a chemical reaction system of the geothermal fluid of the fracture type thermal reservoir, coupling the constructed fracture medium seepage-heat transfer-solute reaction migration control equation to obtain a seepage-heat transfer-solute reaction migration multi-field coupling model; And solving the obtained seepage-heat transfer-solute reaction migration multi-field coupling model, and simulating the evolution of a temperature field, a seepage field and a chemical field in the geothermal exploitation process according to the solving result to finish the water quality evolution simulation of the fracture geothermal reservoir based on the water-rock reaction. As a further technical limitation, the constructed fracture medium seepage-heat transfer-solute reaction migration control equation is subjected to multi-field coupling, and a seepage-heat transfer-solute reaction migration multi-field coupling model is obtained through real-time transmission of state variables and a dynamic updating bidirectional feedback mechanism of physical parameters. As a further technical definition, the established crevice medium seepage-heat transfer-solute reaction migration control equation includes a crevice medium seepage equation, a heat transfer control equation and a reactive solute migration equation. Further, a sequential iteration method is adopted to solve the constructed control equation of the seepage-heat transfer-solute rea