Deep disaster energy and mineral heat co-development method based on stress induction and water pressure compensation

Abstract

The application provides a deep disaster and energy mine heat cooperative development method based on stress induction and water pressure compensation, which comprises the following steps: demarcating a target block in a deep to-be-developed ore body, obtaining multi-field parameters of the target block, and constructing a multi-physical field coupling three-dimensional numerical model; according to the obtained model and identification results, constructing an induction project in the target block to form a pre-crushed area with initial damage in the target area; based on the formed pre-crushed area, constructing a supplementary drill hole to communicate and expand the rock mass fracture, and forming a three-dimensional geothermal extraction fracture network with high permeability; arranging a fracture network formed by connecting the injection well and the production well, and based on water pressure compensation, the high-temperature fluid is collected into the production well and lifted to the surface; after the high-temperature fluid is lifted to the surface, the heat energy is extracted and utilized; and the ore body of the target block is mined after the rock mass of the target block is extracted by geothermal extraction. The application initiatively triggers the directional and controllable release of high ground stress, eliminates the risk of dynamic disasters such as rock burst from the root, and greatly reduces the blasting energy consumption of subsequent mining operations.

Description

Technical Field

[0001] This invention belongs to the field of collaborative development technology of deep mineral and geothermal resources, specifically a method for collaborative development of deep disaster-prone mineral and geothermal resources based on stress induction and water pressure compensation. Background Technology

[0002] As shallow mineral resources become increasingly depleted, mining operations are gradually extending to deeper areas. Deep rock masses are generally situated in complex geological environments characterized by high ground stress, high ground temperature, and high pore water pressure. High ground stress causes the accumulation of enormous elastic potential energy within the rock mass, making it highly susceptible to dynamic disasters such as rock bursts and spalling during excavation and unloading. High ground temperature leads to severe heat hazards in mines, deteriorating the working environment and significantly increasing ventilation and cooling costs. High pore water pressure increases the risk of water inrush and makes deep fluid control difficult.

[0003] Current technologies typically treat these three high-pressure areas (high geothermal energy, high temperature, and high humidity) as sources of disaster requiring countermeasures and management, employing passive defense measures such as strong support, large-scale forced cooling, and forced drainage. For example, to address high-stress rockburst problems, methods such as high-strength anchor bolts and cables, energy-absorbing supports, and stress-relief holes are used; to address high geothermal heat hazards, methods such as ice-making for cooling, air conditioning, and increased ventilation are employed; and to address high pore water pressure problems, methods such as advanced drainage and curtain grouting interception are used. These passive defense measures result in extremely high costs for deep resource development; statistics show that deep mining costs can be 3 to 5 times higher than shallow mining, and the efficiency is low, with significant safety risks remaining.

[0004] On the other hand, existing deep geothermal development is usually conducted independently of mineral extraction, mainly including hydrothermal geothermal development and enhanced geothermal system development. Extracting deep geothermal fluids requires overcoming enormous gravitational potential energy to lift the fluid from a depth of thousands of meters to the surface. For example, at a depth of 1000 meters, lifting one cubic meter of water to the surface requires overcoming a hydrostatic pressure of approximately 10 MPa. This often necessitates surface circulation pumps with extremely high head and power, resulting in huge energy consumption and severely restricting the economic viability of deep geothermal extraction. Furthermore, enhanced geothermal systems require artificial fracturing to form thermal reservoirs, and fracturing energy consumption is also considerable.

[0005] In existing technologies, some scholars have proposed the concept of co-development of mineral and thermal energy, but these are mainly limited to recovering geothermal energy from abandoned mines or extracting waste heat by arranging heat exchangers in goaf areas. They have not truly realized the active conversion and utilization of "three high" disaster energy as an effective energy source.

[0006] In summary, existing deep mineral and geothermal development technologies cannot transform passive disaster prevention into active energy utilization, and are unable to simultaneously meet the multiple needs of disaster prevention, mining efficiency improvement, and efficient geothermal development. Summary of the Invention

[0007] The purpose of this invention is to provide a method for the coordinated development of deep disaster-prone energy, minerals, and thermal resources based on stress induction and water pressure compensation, which takes into account disaster prevention and control, improved mining efficiency, and efficient geothermal development.

[0008] The method for the coordinated development of deep-seated disaster-prone energy, mineral, and thermal resources based on stress-induced and water-pressure compensation provided by this invention includes the following steps:

[0009] S1. Delineate target blocks in deep ore bodies to be developed, obtain multi-field parameters of the target blocks, construct a multi-physics coupled three-dimensional numerical model, and identify high stress concentration areas, main stress transmission paths, potential fracture dominance surfaces, and high permeability channels within the target blocks.

[0010] S2. Based on the model and identification results obtained in step S1, construct an induction project within the target block to actively trigger the directional release and transfer of high ground stress in the target area, forming a pre-fractured zone with initial damage within the target area.

[0011] S3. Based on the pre-fractured zone formed in step S2, additional boreholes are drilled and the rock mass fissures are connected to form a highly permeable three-dimensional geothermal extraction fissure network by connecting the dispersed initial damaged areas.

[0012] S4. Arrange the fracture network formed in step S3 to connect the injection well and the production well. Inject the low-temperature heat transfer fluid into the fracture network through the injection well to form a high-temperature fluid. Based on water pressure compensation, the high-temperature fluid is fed into the production well and lifted to the surface. After the high-temperature fluid is lifted to the surface, the heat energy is extracted and utilized.

[0013] S5. After the temperature of the rock mass in the target block drops below the preset safe operating temperature threshold and the rock mass fracture degree meets the preset mining requirements after geothermal extraction in step S4, the ore body in the target block is mined.

[0014] Step S1 is as follows:

[0015] In deep, undeveloped ore bodies, target mining blocks are delineated. A combination of in-situ testing and laboratory experiments is used to obtain multi-field parameters of the target blocks. The in-situ testing includes hydraulic fracturing for in-situ stress measurement, borehole stress relief for in-situ stress measurement, borehole temperature measurement, and pore water pressure monitoring. The laboratory experiments are used to obtain the basic physical, mechanical, thermal, and hydraulic parameters of the rock mass in the target blocks. Based on the obtained multi-field parameters, a coupled three-dimensional numerical model of thermo-mechanical-fluid multiphysics is constructed using the finite element method, finite difference method, or discrete element method. Through numerical simulation analysis, high-stress concentration zones, main stress transmission paths, potential fracture dominance surfaces, and high-permeability channels within the target blocks are identified.

[0016] In step S2, the implementation of the induction process includes at least one or a combination of the following:

[0017] Method A, Boundary Cutting and Pressure Relief Induction Engineering: At at least one of the bottom horizontal plane, top horizontal plane, or lateral boundary of the target rock mass, construct narrow cuts, large-diameter densely arranged holes, or thin-layer pressure relief tunnels to create artificial free surfaces, cut off the main path of stress transmission, and induce shear slip fracture or tension fracture of the rock mass towards the free surface, forming a shear fracture zone;

[0018] Method B, Geometric Stress Concentration Induction Engineering: In the high stress concentration area inside the target rock mass, a stress concentration induction chamber with non-smooth cross-section is constructed. The high stress concentration effect generated by the geometric shape of sharp corners or edges is used to induce the generation of initial tension splitting cracks and their extension into the depth, forming a tension splitting zone.

[0019] The cross-section of the stress concentration induction chamber includes rectangular, rhomboid, star-shaped, or irregular shapes with sharp corners; the cross-sectional dimensions of the stress concentration induction chamber are determined according to the ground stress level and rock mass strength to ensure that the stress concentration coefficient at the sharp corners is sufficient to make the local stress exceed the rock mass strength limit.

[0020] Step S3 is as follows:

[0021] Based on the pre-fractured zone and initial damage field formed in step S2, the completed induced engineering space is used as a construction platform for supplementary drilling. Hydraulic fracturing technology or a combination of hydraulic fracturing and deep-hole controlled blasting is used to connect and extend rock fractures, linking the dispersed initial damage zones to form a highly permeable three-dimensional geothermal extraction fracture network, serving as a fractured geothermal reservoir for subsequent geothermal extraction. When hydraulic fracturing technology is used, segmented fracturing or multi-cluster fracturing methods are employed, with water or low-viscosity slickwater used as the fracturing fluid. When a combination of hydraulic fracturing and deep-hole controlled blasting is used, an initial fracture network is first formed through hydraulic fracturing, and then the dynamic stress waves generated by deep-hole controlled blasting are used to disturb and promote fracture penetration and increase permeability.

[0022] Step S4 is as follows:

[0023] Injection wells and production wells are arranged so that both are connected to the fracture network formed in step S3, establishing an underground thermal fluid circulation system and a surface thermal energy extraction system. Low-temperature heat-carrying fluid is injected into the fracture network through the injection wells. As the fluid flows through the fracture channels, it exchanges heat with the high-temperature rock mass, absorbing heat to form a high-temperature fluid. This high-temperature fluid flows into the production wells and is lifted to the surface. During the lifting process, the potential energy provided by the in-situ high-pore water pressure in the deep strata is used to compensate for the water pressure, helping to overcome the resistance of gravity lifting. After reaching the surface, the high-temperature fluid's thermal energy is extracted and utilized by the surface thermal energy extraction system. The low-temperature heat-carrying fluid is recycled water that has undergone surface cooling treatment, or supplemented surface water or mine water. The surface thermal energy extraction system includes a surface heat exchanger group, a heat pump unit, a thermal storage device, and a heating network. The extracted thermal energy is used for heating buildings in the mining area, preheating mine intake air, supplying industrial hot water, or generating geothermal power.

[0024] Step S5 is as follows:

[0025] When the rock mass of the target block is extracted by geothermal energy in step S4 and the temperature drops below the preset safe operating temperature threshold, and the rock mass is subjected to stress-induced damage accumulation in step S2, fracture propagation in step S3, and long-term water injection thermal shock in step S4, and the degree of fragmentation reaches the preset mining requirements, a large-scale low-energy mining method is adopted to mine the ore body of the target block; the preset safe operating temperature threshold is determined according to the mine heat hazard level standard; the preset mining requirements are that the degree of rock mass fragmentation reaches the mining conditions suitable for the corresponding mining method; the large-scale low-energy mining method includes bottomless sublevel caving, staged forced caving, or backfilling mining.

[0026] The above method also includes a full-process multi-field monitoring and dynamic control step. During the implementation of steps S2 to S5, a microseismic monitoring system, a temperature monitoring system, and a pore water pressure monitoring system are deployed to monitor the rock mass damage evolution, temperature field changes, and water pressure distribution in real time. Based on the monitoring data, the induced engineering parameters, injection and production flow rates, and mining progress are dynamically adjusted.

[0027] The sensors of the microseismic monitoring system are installed at different depths and orientations around the target block through boreholes, forming a three-dimensional monitoring network to record the time, location, magnitude, and energy parameters of microseismic events; the probes of the temperature monitoring system are installed at different locations and depths within the fractured thermal reservoir through boreholes; and the monitoring points of the pore water pressure monitoring system are arranged in injection wells, production wells, and dedicated monitoring boreholes.

[0028] The specific rules for dynamic regulation are as follows: when the microseismic monitoring system detects an abnormal increase in microseismic activity, indicating a risk of rock mass instability, the construction progress of the induction project is suspended or slowed down, and resumed after the stress release stabilizes; when the temperature monitoring system detects a risk of thermal breakthrough in a local area, the injection and production flow rates and inter-well pressure differentials of the injection wells and production wells are adjusted; when the pore water pressure monitoring system detects an abnormal increase in pressure within the formation or fractured thermal reservoir, the injection pressure is reduced or the production flow rate of the production wells is increased.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. By combining boundary cutting and pressure relief with geometric stress concentration induction, the high ground stress is actively triggered and released in a directional and controllable manner, converting the elastic potential energy contained in the rock mass into the damage and fracture energy of the rock mass; this eliminates the risk of dynamic disasters such as rock bursts from the root, and at the same time forms a large-scale pre-fracture zone in the target ore body, which greatly reduces the blasting energy consumption of subsequent mining operations, achieving the dual benefits of disaster prevention and mining efficiency, and breaking the technical limitations of the traditional separation between disaster prevention and mining;

[0031] 2. By deeply integrating the geothermal extraction process with the mining pretreatment process, a closed-loop process of "pre-fracture - fracture mesh construction - thermal extraction - collaborative mining" has been formed. During the process of geothermal energy extraction through hot fluid circulation, the thermal shock effect generated by the low-temperature heat carrier fluid on the high-temperature rock mass further promotes the expansion and fragmentation of rock mass fractures, while continuously reducing the temperature of the rock mass. This simultaneously completes the two major pretreatment processes required for mining: rock mass pre-fracture and working environment cooling. No additional investment in related engineering costs is required, which maximizes the benefits of developing both mineral and geothermal resources and solves the problem that traditional mineral-geothermal co-development can only utilize the residual heat of abandoned mines and cannot be deeply integrated with the mining process.

[0032] 3. Utilizing the natural potential energy of the high pore water pressure in the deep strata, pressure compensation is provided for the surface lifting of the thermal fluid; based on the principle of communicating vessels, the high-pressure groundwater in the deep strata provides the supporting potential energy for the rising fluid in the production well, which offsets most of the gravitational potential energy loss that needs to be overcome for fluid lifting, significantly reducing the head requirement and operating power of the surface circulation pump, solving the problems of excessive energy consumption and poor economic efficiency in traditional deep geothermal development, and significantly improving the feasibility and profitability of deep geothermal development. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a method flow according to an embodiment of the present invention.

[0034] Figure 2 This is a schematic cross-sectional view of the implementation principle of stress field targeted induction and disaster energy conversion pre-fracture in this method.

[0035] Figure 3This is a schematic diagram of the planar layout of the fracture network for three-dimensional geothermal extraction in this method.

[0036] Figure 4 This is a schematic diagram of the high-water-pressure compensated thermal fluid circulation extraction system in this method.

[0037] The attached figures are labeled as follows:

[0038] 1. Target ore body block; 2. Induction engineering system; 21. Bottom cutting and pressure relief roadway; 22. Geometric induction chamber; 23. Lateral cutting borehole; 3. Fracture network system; 31. Shear fracture zone; 32. Tension splitting zone; 33. Hydraulic pressure fracture; 34. Through fracture network; 4. Thermal fluid circulation system; 41. Surface thermal energy extraction station; 42. Water injection well; 43. Production well; 44. Fractured thermal reservoir; 45. Surface circulation pump; 5. Formation environment; 51. High-stress rock mass; 52. High-pore water pressure aquifer; 53. Stress transmission path; 61. Microseismic monitoring sensor; 62. Temperature monitoring probe; 63. Pore water pressure monitoring point. Detailed Implementation

[0039] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are only a part of the embodiments, not all of the 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] like Figure 1 As shown in this embodiment, the deep disaster energy, mineral, and thermal synergistic development method based on stress-induced and water pressure compensation disclosed includes the following steps:

[0041] S1. Detailed Evaluation and 3D Modeling of Multi-Field Parameters: Target blocks are delineated within the deep, undeveloped ore body. Multi-field parameters of the target blocks are obtained, and a multi-physics coupled 3D numerical model is constructed to identify high-stress concentration zones, main stress transmission paths, potential fracture dominance surfaces, and high-permeability channels within the target blocks. Specific steps are as follows:

[0042] In the deep ore bodies to be developed, target mining blocks are delineated, and multi-field parameters of the target blocks are obtained by combining in-situ testing and laboratory testing.

[0043] In-situ testing includes hydraulic fracturing for in-situ stress measurement, borehole stress relief for in-situ stress measurement, borehole temperature measurement, and pore water pressure monitoring; laboratory tests are used to obtain the basic physical, mechanical, thermal, and hydraulic parameters of the rock mass in the target block.

[0044] Multiple parameters include the distribution of geostress tensor, rock mass temperature field, formation pore water pressure gradient, rock mass mechanical parameters, rock mass thermal parameters, and rock mass hydraulic parameters;

[0045] Based on the acquired multi-field parameters, a three-dimensional numerical model of thermo-mechanical-fluid multi-physics coupling is constructed using the finite element method, finite difference method, or discrete element method. Through numerical simulation analysis, high stress concentration areas, main stress transmission paths, potential fracture dominance surfaces, and high permeability channels within the target block are identified, providing a basis for the design of subsequent induction engineering.

[0046] S2. Stress Field Targeted Induction and Disaster Energy Conversion Pre-fracture: Based on the model and identification results obtained in step S1, induction engineering is carried out within the target block to actively trigger the directional release and transfer of high ground stress in the target area, forming a pre-fracture zone with initial damage within the target area; the specific steps are as follows:

[0047] Based on the three-dimensional numerical model and identification results obtained in step S1, an induction project is planned and constructed within the target block. By utilizing the excavation unloading effect and the stress concentration effect caused by the geometry, the high ground stress is actively triggered to release and transfer stress in the target area, converting the elastic potential energy contained in the rock mass into the damage and fracture energy of the rock mass, forming a pre-fractured zone with initial damage in the target area, while eliminating the risk of dynamic disasters such as rock bursts.

[0048] The implementation methods of induction engineering include at least one or a combination of the following:

[0049] Method A, Boundary Cutting and Pressure Relief Induction Engineering: At at least one of the bottom horizontal plane, top horizontal plane, or lateral boundary of the target rock mass, construct a narrow cutting slot, a large-diameter dense row of holes, or a thin-layer pressure relief tunnel to create an artificial free surface, cut off the main path of stress transmission, so that the cut and isolated rock mass loses its surrounding constraints, induces shear slip fracture or tension fracture of the rock mass in the direction of the free surface, and forms a shear fracture zone.

[0050] Method B, Geometric Stress Concentration Induction Engineering: In the high stress concentration area inside the target rock mass, a stress concentration induction chamber with non-smooth cross-sectional characteristics is constructed. The cross-sectional characteristics of the chamber include rectangular, rhomboid, star-shaped, or irregular shapes with sharp corners. The high stress concentration effect generated by the geometric shape with sharp corners or edges is used to make the local stress in the chamber exceed the rock mass strength limit, inducing the generation of initial tension splitting cracks and their propagation into the depth, forming a tension splitting zone.

[0051] The cross-sectional dimensions of the stress concentration induction chamber are determined based on the geostress level and rock mass strength to ensure that the stress concentration factor at the sharp corners is sufficient to cause the local stress to exceed the rock mass strength limit.

[0052] S3. Construction of a Three-Dimensional Geothermal Extraction Fracture Network: Based on the pre-fractured zone formed in step S2, additional boreholes are drilled to connect and extend rock fractures, thus connecting the dispersed initial damaged areas to form a highly permeable three-dimensional geothermal extraction fracture network; the specific steps are as follows:

[0053] Based on the pre-fractured zone and initial damage field formed in step S2, the space of the completed induction engineering is used as a construction platform to carry out supplementary drilling; hydraulic fracturing technology or hydraulic fracturing combined with deep hole controlled blasting technology is used to connect and expand rock mass fractures, and the dispersed initial damage zones are connected to form a highly permeable three-dimensional geothermal extraction fracture network, which serves as a fractured heat reservoir for subsequent geothermal extraction.

[0054] When using hydraulic fracturing technology, staged fracturing or multi-cluster fracturing methods should be adopted, and clean water or low-viscosity slickwater should be used as the fracturing fluid to reduce damage to the permeability of the fracture.

[0055] When using a combination of hydraulic fracturing and deep-hole controlled blasting, an initial fracture network is first formed through hydraulic fracturing, and then the dynamic stress waves generated by deep-hole controlled blasting are used to disturb and promote fracture penetration and increase permeability.

[0056] S4. High-pressure compensated thermal fluid circulation and geothermal extraction: The fracture network formed in step S3, connecting injection wells and production wells, is arranged. Low-temperature heat transfer fluid is injected into the fracture network through the injection wells to form high-temperature fluid. Based on water pressure compensation, the high-temperature fluid is channeled into the production wells and pumped to the surface. After reaching the surface, the high-temperature fluid's thermal energy is extracted and utilized. The specific steps are as follows:

[0057] Arrange water injection wells and production wells so that both water injection wells and production wells are connected to the fracture network formed in step S3, and establish a downhole thermal fluid circulation system and a surface thermal energy extraction system;

[0058] The working principle of the downhole hot fluid circulation system is as follows: Low-temperature heat carrier fluid is injected into the fracture network through the injection well. When the fluid flows in the fracture channel, it exchanges heat with the high-temperature rock mass and absorbs the heat of the rock mass to form a high-temperature fluid. The high-temperature fluid flows into the production well and is lifted to the surface. During the lifting process, the potential energy provided by the high pore water pressure in the deep formation is used to compensate for the water pressure of the high-temperature fluid and help overcome the gravity lifting resistance.

[0059] The low-temperature heat transfer fluid is circulating return water that has undergone ground cooling treatment, or supplementary surface water or mine water;

[0060] The principle of water pressure compensation is as follows: The natural high-pressure groundwater in the deep aquifer or fracture network forms a pressure field. According to the principle of communicating vessels, when the production well is connected to the deep high-pressure aquifer or fracture network, the deep high-pressure fluid provides the upward initial driving force or support potential energy for the rising fluid in the production well, so that the wellhead of the production well has a certain self-flowing pressure or a significantly reduced dynamic water level, thereby offsetting part of the gravitational potential energy loss in the lift pipeline and reducing the head requirement and operating power of the surface circulation pump system.

[0061] When the high-temperature fluid reaches the surface, the heat energy is extracted and utilized through a ground heat energy extraction system. The ground heat energy extraction system includes a ground heat exchanger group, a heat pump unit, a heat storage device, and a heating network. The extracted heat energy can be used for heating buildings in the mining area, preheating of mine intake air, industrial hot water supply, or geothermal power generation.

[0062] In addition, during the circulation of the hot fluid, the continuously injected low-temperature heat carrier fluid generates a thermal shock effect on the high-temperature rock mass. The surface of the rock mass generates thermal stress due to rapid cooling, which induces thermal cracking, further fracturing the rock mass in the fractured heat reservoir, continuously increasing porosity and permeability, while simultaneously achieving a continuous decrease in rock mass temperature.

[0063] S5. Low-energy collaborative mining of cold-brittle rock mass: After the geothermal extraction in step S4, the temperature of the rock mass in the target block drops below the preset safe operating temperature threshold, and the rock mass fracture degree meets the preset mining requirements, the ore body in the target block is then mined; the specific steps are as follows:

[0064] When the rock mass of the target block is extracted by geothermal energy in step S4 and the temperature drops below the preset safe operating temperature threshold, and the rock mass is subjected to stress-induced damage accumulation in step S2, fissure propagation in step S3, and long-term water injection thermal shock in step S4, and the degree of fragmentation reaches the preset mining requirements, the target block ore body is mined using a large-scale low-energy mining method.

[0065] The preset safe operating temperature threshold is determined according to the mine heat hazard level standard; the preset mining requirement is that the rock mass is fractured to a degree suitable for the corresponding mining method.

[0066] Large-scale low-energy mining methods include pillarless sublevel caving, staged forced caving, or backfilling mining, which utilize the pre-fractured and brittle characteristics of the rock mass to reduce the energy consumption of mining blasting.

[0067] This method also includes a full-process multi-field monitoring and dynamic control step. During the implementation of steps S2 to S5, a microseismic monitoring system, a temperature monitoring system, and a pore water pressure monitoring system are deployed to monitor the rock mass damage evolution, temperature field changes, and water pressure distribution in real time. Based on the monitoring data, the induced engineering parameters, injection and production flow rates, and mining progress are dynamically adjusted.

[0068] The sensors of the microseismic monitoring system are installed at different depths and orientations around the target block through boreholes, forming a three-dimensional monitoring network. This network is used to monitor the damage evolution process of the rock mass in real time, record the time, location, magnitude and energy parameters of microseismic events, assess the formation effect of the pre-fractured zone, and monitor the risk of rockburst.

[0069] The probes of the temperature monitoring system are installed at different locations and depths within the fractured geothermal reservoir through boreholes. They are used to monitor the spatiotemporal evolution of the rock mass temperature field within the target block, assess the geothermal extraction effect, monitor the risk of thermal breakthrough, and provide a basis for determining the safe operating temperature conditions in step S5.

[0070] The monitoring points of the pore water pressure monitoring system are arranged in injection wells, production wells, and dedicated monitoring wells. It is used to monitor the pressure state of deep aquifers and the pressure field changes in fractured thermal reservoirs during injection and production, optimize injection and production parameters, evaluate the effect of water pressure compensation, and prevent the induction of adverse geological responses.

[0071] The specific rules for dynamic regulation are as follows:

[0072] When the microseismic monitoring system detects an abnormal increase in microseismic activity, indicating a risk of rock mass instability, the construction progress of the induction project is suspended or slowed down, and resumed after the stress release stabilizes; when the temperature monitoring system detects a risk of thermal breakthrough in a local area, the injection and production flow rates and inter-well pressure differentials of the injection and production wells are adjusted; when the pore water pressure monitoring system detects an abnormal increase in pressure within the formation or fractured thermal reservoir, the injection pressure is reduced or the production flow rate of the production wells is increased to ensure the safe operation of the system.

[0073] The following example, taken in a deep, high-stress hard rock metal mine, illustrates the implementation process of this method in detail:

[0074] The geological environment 5 of this mine exhibits typical characteristics of high stress, high pressure, and high pore pressure. High-stress rock masses 51 are widely distributed in the deep strata, with high innate rock stress levels. The maximum horizontal principal stress reaches 45 MPa, and the vertical stress is approximately 30 MPa. The horizontal principal stress is significantly higher than the vertical stress, classifying it as a tectonic stress-dominated high-stress mine with a significant risk of rockburst. A high-pore-pressure aquifer 52 is also present in the deep strata, with a measured pore-pressure of approximately 10 MPa, indicating it is a confined aquifer.

[0075] Step S1: Detailed evaluation of multiple field parameters and 3D modeling

[0076] First, exploration boreholes and testing chambers were deployed in the target ore body block 1 and its surrounding stratigraphic environment 5 to conduct detailed multi-field parameter tests. Hydraulic fracturing was used to measure in-situ stress at different depths in multiple boreholes to obtain the distribution law of in-situ stress tensor within the high-stress rock mass 51 and identify the spatial distribution characteristics of the stress transmission path 53. Borehole thermometry was used to obtain the geothermal gradient and determine the temperature field distribution of the target ore body block 1. A pore water pressure monitoring device was installed in the deep boreholes to determine the water pressure value of the high-pore water pressure aquifer 52 and its relationship with depth.

[0077] Based on test data, a three-dimensional numerical model of the target ore body block 1 and its surrounding geological environment 5 was constructed using finite difference or finite element software. The model included a thermo-mechanical-fluid multi-field coupled calculation module, inputting rock mechanics, thermal, and hydraulic parameters. Through numerical simulation analysis, the locations of high stress concentration zones within the target ore body block 1 were identified, the main path of stress transmission path 53 was determined, and dominant joint surfaces were identified as potential fracture surfaces, providing a basis for the subsequent design of the induced engineering system 2.

[0078] Step S2: Stress field targeted induction and disaster energy conversion pre-fracture

[0079] See Figure 2 and Figure 3 Based on the evaluation and modeling results of step S1, the induction engineering system 2 is designed. In this embodiment, the induction engineering system 2 adopts a combination of "boundary cutting and pressure relief + geometric stress concentration induction", including three induction engineering forms: bottom cutting and pressure relief roadway 21, geometric induction chamber 22, and lateral cutting borehole 23.

[0080] First, a bottom-cutting and pressure-relief tunnel 21 is constructed horizontally at the bottom of the target ore body block 1. For example... Figure 2 As shown, the bottom cutting and stress relief roadway 21 is located at the bottom boundary of the target ore body block 1. It adopts a narrow cross-section design and its length extends through the bottom boundary of the target ore body block 1. The roadway is constructed using a hard rock tunnel boring machine or controlled blasting method, with enhanced temporary support during construction. The function of the bottom cutting and stress relief roadway 21 is to cut off the stress transmission path 53 at the bottom of the target ore body block 1, causing the high-stress rock mass 51 above the roadway to lose its lower support and form a free bottom surface.

[0081] After the bottom cutting and decompression tunnel 21 is constructed, the high-stress rock mass 51 above it will undergo shear slip and tensile fracture in the direction of the tunnel space under high horizontal stress. Numerous microseismic events in the rock mass above the tunnel after construction can be observed using microseismic monitoring sensors 61 arranged around the perimeter. Figure 2 The shear fracture zone 31 is marked in the middle. The shear fracture zone 31 extends upward from the top of the bottom cutting and decompression tunnel 21, significantly reducing the integrity of the rock mass and effectively releasing elastic potential energy.

[0082] Secondly, a geometric induction chamber 22 was constructed in the central part of the target ore body block 1. For example... Figure 2 As shown, based on the stress field distribution characteristics identified in step S1, the geometrically induced chamber 22 is located at the core of the high-stress rock mass 51 concentration zone. The cross-section of the geometrically induced chamber 22 is designed as a rectangle. The four sharp corners of the rectangular cross-section generate a significant stress concentration effect under high ground stress, with a theoretical stress concentration coefficient of 3-5 times. This causes the local stress at the sharp corners to far exceed the tensile strength of the rock mass, thereby inducing the initiation of tension splitting cracks.

[0083] After the construction of the geometric induction chamber 22 was completed, tension splitting cracks began to appear at the four sharp corners. The cracks propagated deeper along the direction parallel to the maximum principal stress, forming... Figure 2 The tension-split zone 32 is marked in the middle. The tension-split zone 32 extends outward from the sharp corner of the chamber, and the cracks are distributed radially.

[0084] In addition, lateral cutting boreholes 23 were constructed at the lateral boundary of the target ore body block 1. For example... Figure 2 and Figure 4 As shown, the lateral cutting boreholes 23 consist of a row of parallel, large-diameter boreholes arranged perpendicular to the lateral boundary, penetrating the lateral boundary of the target ore body block 1. The function of the lateral cutting boreholes 23 is to cut off the lateral stress transmission path 53 of the target ore body block 1, and together with the bottom cutting and stress relief tunnel 21, form a more complete boundary cutting effect, further promoting stress release in the high-stress rock mass 51.

[0085] Through the combined implementation of the aforementioned induced engineering system 2, the high geostress elastic potential energy accumulated within the target ore body block 1 was successfully converted into damage and fracturing energy of the rock mass. The shear fracture zone 31 and the tension splitting zone 32 together constitute the initial damage basis of the fracture network system 3. Energy that might have been suddenly released in the form of rockburst was transformed into controllable, slow rock mass fracturing, effectively eliminating the risk of rockburst.

[0086] Step S3: Construction of Three-Dimensional Geothermal Extraction Fracture Network

[0087] See Figure 3 Based on the shear fracture zone 31 and tension splitting zone 32 formed in step S2, a complete fracture network system 3 is further constructed to form a three-dimensional geothermal extraction fracture network.

[0088] First, using the bottom cutting and pressure relief roadway 21 and the geometric induction chamber 22 as construction platforms, supplementary boreholes are drilled into the shear fracture zone 31 and the tension splitting zone 32. For example... Figure 4 As shown, boreholes are arranged in a fan shape from the bottom cutting and decompression roadway 21 upwards, with the borehole trajectory passing through the shear fracture zone 31; boreholes are arranged radially from the geometric induction chamber 22 in all directions, with the borehole trajectory passing through the tension splitting zone 32.

[0089] Then, segmented hydraulic fracturing technology was used to fracturing each borehole, forming hydraulically fractured fracture 33. The fracturing fluid consisted of clean water with a small amount of drag-reducing agent to minimize damage to the fracture permeability. Figure 4 As shown, under the control of the geostress field, the hydraulic pressure fracture 33 mainly extends along the direction perpendicular to the minimum principal stress, and the half-length of a single fracture can reach 20-50m. At the same time, guided by the initial damage field formed in step two, the hydraulic pressure fracture 33 preferentially extends and connects with the shear fracture zone 31 and the tension splitting zone 32.

[0090] After the hydraulic fracturing is completed, the shear fracture zone 31, the tension splitting zone 32, and the hydraulic fracture 33 are interconnected, forming a highly permeable interconnected fracture network 34. The interconnected fracture network 34 is distributed in a three-dimensional network in space, constituting the main structure of the fracture network system 3, and providing the foundation for the fractured geothermal reservoir 44 for subsequent geothermal extraction.

[0091] Step S4: High-pressure compensated thermal fluid circulation extraction

[0092] See Figure 4 After the fracture network system 3 is constructed, a thermal fluid circulation system 4 is established, including a ground thermal energy extraction station 41, a water injection well 42, a production well 43, a fracture thermal reservoir 44, and a ground circulation pump 45.

[0093] Injection well 42 and production well 43 are drilled from the surface into the fractured geothermal reservoir 44. Both injection well 42 and production well 43 are drilled into the interior of the fractured geothermal reservoir 44 and connected to the through fracture network 34. A surface circulation pump 45 is located at the wellhead of injection well 42 and is used to provide driving force for the circulation system.

[0094] During operation, the low-temperature circulating water, after being cooled by heat exchange at the ground thermal energy extraction station 41, is pressurized by the ground circulation pump 45 and injected into the deep fractured thermal reservoir 44 through the injection well 42. The low-temperature water flows through the fracture channels of the fracture network 34, undergoing convective heat exchange with the high-temperature rock mass, and gradually heats up to form high-temperature hot water. The high-temperature hot water flows into the production well 43 and is pumped to the surface along the well shaft.

[0095] like Figure 4 As shown, during the hot water lifting process, this invention innovatively utilizes the in-situ high pore water pressure in the high-pore water pressure aquifer 52 for pressure compensation. The high-pore water pressure aquifer 52 deep within the mining area is adjacent to or connected to the fractured thermal reservoir 44. According to the principle of communicating vessels, when the production well 43 is connected to the high-pore water pressure aquifer 52, the high-pressure fluid in the deep area provides upward supporting potential energy for the rising water column in the production well 43.

[0096] Specifically, taking a well depth of 1200m as an example, in a traditional geothermal system, the hydrostatic pressure that needs to be overcome to lift hot water from the bottom of the well to the surface is approximately ρgh≈12MPa (ρ is the density of water, g is the acceleration due to gravity, and h is the depth). However, in this invention, because the high-pore-pressure aquifer 52 provides a pore-pressure of P0≈10MPa to compensate for the lifting process, the actual net pressure that needs to be overcome is only ρgh-P0≈2MPa. This means that the hot water in the production well 43 can flow to the surface almost by gravity under the support of the deep pore-pressure, only needing to overcome frictional losses and local resistance losses. Therefore, the surface circulation pump 45 only needs to provide a small head to maintain the system's circulation operation, and the operating power of the circulation pump is correspondingly reduced significantly.

[0097] The heat exchanger at the ground-based heat extraction station 41 transfers the heat energy of the high-temperature hot water to the secondary heating circulating water, and the heat pump unit further improves the heat energy quality to the required heating temperature. The circulating water, after being cooled by heat exchange, is then injected back into the ground, forming a closed loop.

[0098] During geothermal extraction, the continuously injected low-temperature water exerts a water-quenching and cold-shock effect on the high-temperature rock mass. Rapid cooling of the rock surface generates thermal stress, inducing heat and cracking, further fracturing the rock mass within the fractured geothermal reservoir 44, leading to a continuous increase in porosity and permeability. Simultaneously, continuous heat exchange gradually reduces the temperature of the rock mass in the target ore block 1, gradually eliminating thermal hazards.

[0099] Step S5: Co-extraction of cold-brittle rock mass

[0100] After the hot fluid circulation system 4 has been running continuously for a period of time, the temperature changes of the rock mass are monitored in real time by temperature monitoring probes 62 deployed in the target ore block 1. When the monitoring data shows that the rock mass temperature of the target ore block 1 has dropped below the preset safe operating temperature threshold, the heat hazard problem is solved and safe operating conditions are met.

[0101] Simultaneously, the rock mass of Block 1 in the target ore body underwent a superimposed effect of three fracturing processes: the first was the shear fracture zone 31 and tension splitting zone 32 induced by the induced engineering system 2 in step S2, forming initial damage; the second was the expansion of hydraulic fracturing fractures 33 and the through fracture network 34 generated by hydraulic fracturing in step S3; and the third was the water quenching and cold impact fracturing caused by long-term water injection in step S4. After the superposition of the three processes, the rock mass fragmentation was significantly increased, the block size was significantly reduced, and the rock mass exhibited obvious embrittlement characteristics.

[0102] At this point, the bottomless segmented caving method or the staged forced caving method is used to mine the target ore block 1. Because the rock mass is pre-fractured and its brittleness is significantly enhanced, the explosive consumption per unit of caving blasting is reduced. Simultaneously, due to the substantial decrease in rock mass temperature, the working environment is significantly improved, eliminating the need for high-power refrigeration equipment and drastically reducing ventilation energy consumption.

[0103] After the ore collapses, it is transported out via the ore inlet and enters the mineral processing flow. The mine water generated during the mining process is treated and can be used as a supplementary water source for the thermal fluid circulation system 4, realizing the recycling of water resources.

[0104] During the implementation of steps S2 to S5, a monitoring system 6 is deployed for comprehensive real-time monitoring and dynamic control. The monitoring system 6 includes a microseismic monitoring sensor 61, a temperature monitoring probe 62, and a pore water pressure monitoring point 63.

[0105] Microseismic monitoring sensors 61 are deployed in the geological environment 5 surrounding the target ore body block 1. They are installed at different depths and orientations around the target ore body block 1 through boreholes, forming a three-dimensional monitoring network. The microseismic monitoring sensors 61 are used to monitor the damage evolution process of the high-stress rock mass 51 in real time, record parameters such as the time, location, magnitude, and energy of microseismic events during and after the construction of the induced engineering system 2, assess the formation effect of the shear fracture zone 31 and the tension splitting zone 32, and monitor the risk of rockburst.

[0106] Temperature monitoring probes 62 are deployed at different locations and depths within the fractured thermal reservoir 44 and installed via boreholes. These probes are used to monitor the spatiotemporal evolution of the rock mass temperature field within the target ore block 1, assess the geothermal extraction effect of the thermal fluid circulation system 4, monitor the risk of thermal breakthrough, and provide a basis for determining safe operating temperature conditions in step S5.

[0107] Pore ​​water pressure monitoring points 63 are arranged in injection wells 42, production wells 43 and dedicated monitoring holes. Pore water pressure monitoring points 63 are used to monitor the pressure state of high pore water pressure aquifers 52 and the pressure field changes in fractured thermal reservoirs 44 during injection and production, optimize injection and production parameters, evaluate pressure compensation effects, and prevent the induction of adverse geological responses.

[0108] Based on the monitoring data from monitoring system 6, the process parameters are dynamically adjusted:

[0109] When the microseismic monitoring sensor 61 detects an abnormal increase in microseismic activity, indicating a risk of instability in the high-stress rock mass 51, the construction progress of the induction engineering system 2 is suspended or slowed down, and resumed after the stress release stabilizes; when the temperature monitoring probe 62 detects a risk of thermal breakthrough in a local area (i.e., the injected cold water penetrates too quickly into the production well, causing a drop in the temperature of the produced water), the injection and production flow rates and the pressure difference between the wells are adjusted in the injection well 42 and the production well 43; when the pore water pressure monitoring point 63 detects an abnormal increase in pressure in the high-pore water pressure aquifer 52 or the fractured thermal reservoir 44, the injection pressure is reduced or the production flow rate of the production well 43 is increased to ensure the safe operation of the system.

[0110] This invention enables the resource-based transformation and utilization of energy from deep-seated "three-high" disasters (high stress, high pressure, and high pore pressure). The elastic potential energy contained in the high-stress rock mass 51 is converted into rock fracture energy through the induced engineering system 2, which not only eliminates the risk of rockburst but also reduces the energy consumption of subsequent mining blasting. The geothermal energy in the formation environment 5 is extracted and utilized through the hot fluid circulation system 4, while simultaneously cooling and embrittlement of the rock mass. The fluid potential energy in the high-pore-pressure aquifer 52 is used to compensate for the power consumption of hot water lifting, significantly reducing the energy consumption of the surface circulation pump 45.

[0111] Compared with traditional passive disaster prevention methods, this invention avoids the investment and operation of high-energy-consuming equipment such as strong support, forced cooling, and high-power circulating pumps, and realizes safe, low-carbon, collaborative and efficient mining of deep mineral and geothermal resources.

[0112] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the foregoing embodiments have been described in detail, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features.

[0113] For example, the induction engineering system can use only bottom cutting decompression roadways or only geometric induction chambers, and the application of lateral cutting boreholes can be increased or decreased according to specific geological conditions; the number of injection wells and production wells in the thermal fluid circulation system can be adjusted according to the scale of the fractured thermal reservoir; the sensor layout density of the monitoring system can be optimized according to the monitoring accuracy requirements.

[0114] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A method for the coordinated development of deep-seated disaster-prone energy, mineral, and thermal resources based on stress-induced and water-pressure-compensated methods, characterized in that, Includes the following steps: S1. Delineate target blocks in deep ore bodies to be developed, obtain multi-field parameters of the target blocks, construct a multi-physics coupled three-dimensional numerical model, and identify high stress concentration areas, main stress transmission paths, potential fracture dominance surfaces, and high permeability channels within the target blocks. S2. Based on the model and identification results obtained in step S1, construct an induction project within the target block to actively trigger the directional release and transfer of high ground stress in the target area, forming a pre-fractured zone with initial damage within the target area. S3. Based on the pre-fractured zone formed in step S2, additional boreholes are drilled and the rock mass fissures are connected to form a highly permeable three-dimensional geothermal extraction fissure network by connecting the dispersed initial damaged areas. S4. Arrange the fracture network formed in step S3 to connect the water injection well and the production well. Inject the low-temperature heat transfer fluid into the fracture network through the water injection well to form a high-temperature fluid. High-temperature fluid is pumped into the production well and lifted to the surface based on water pressure compensation; After the high-temperature fluid is lifted to the surface, its thermal energy is extracted and utilized. S5. After the temperature of the rock mass in the target block drops below the preset safe operating temperature threshold and the rock mass fracture degree meets the preset mining requirements after geothermal extraction in step S4, the ore body in the target block is mined.

2. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 1, characterized in that, The specific steps of S1 are as follows: In the deep orebody to be developed, target mining blocks are delineated, and a combination of in-situ testing and laboratory testing is used to obtain multi-field parameters of the target blocks. The in-situ testing includes stress measurement by hydraulic fracturing, stress measurement by casing stress relief, borehole temperature measurement, and pore water pressure monitoring. The laboratory testing is used to obtain the basic physical, mechanical, thermal, and hydraulic parameters of the rock mass of the target blocks. Based on the acquired multi-field parameters, a three-dimensional numerical model of thermo-mechanical-fluid multi-physics coupling is constructed using the finite element method, finite difference method, or discrete element method. Through numerical simulation analysis, high stress concentration areas, main stress transmission paths, potential fracture dominance surfaces, and high permeability channels within the target block are identified.

3. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 1, characterized in that, In step S2, the implementation of the induction process includes at least one or a combination of the following: Method A, Boundary Cutting and Pressure Relief Induction Engineering: At at least one of the bottom horizontal plane, top horizontal plane, or lateral boundary of the target rock mass, construct narrow cuts, large-diameter densely arranged holes, or thin-layer pressure relief tunnels to create artificial free surfaces, cut off the main path of stress transmission, and induce shear slip fracture or tension fracture of the rock mass towards the free surface, forming a shear fracture zone; Method B, Geometric Stress Concentration Induction Engineering: In the high stress concentration area inside the target rock mass, a stress concentration induction chamber with non-smooth cross-section is constructed. The high stress concentration effect generated by the geometric shape of sharp corners or edges is used to induce the generation of initial tension splitting cracks and their extension into the depth, forming a tension splitting zone. The cross-section of the stress concentration induction chamber includes rectangular, rhomboid, star-shaped, or irregular shapes with sharp corners; the cross-sectional dimensions of the stress concentration induction chamber are determined according to the ground stress level and rock mass strength to ensure that the stress concentration coefficient at the sharp corners is sufficient to make the local stress exceed the rock mass strength limit.

4. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 1, characterized in that, Step S3 is as follows: Based on the pre-fractured zone and initial damage field formed in step S2, the space of the completed induction engineering is used as a construction platform to carry out supplementary drilling; hydraulic fracturing technology or hydraulic fracturing combined with deep hole controlled blasting technology is used to connect and expand rock mass fractures, and the dispersed initial damage zones are connected to form a highly permeable three-dimensional geothermal extraction fracture network, which serves as a fractured heat reservoir for subsequent geothermal extraction. When hydraulic fracturing technology is used, staged fracturing or multi-cluster fracturing methods are adopted, and the fracturing fluid is clean water or low-viscosity slickwater. When hydraulic fracturing and deep hole controlled blasting are combined, an initial fracture network is first formed by hydraulic fracturing, and then the dynamic stress wave generated by deep hole controlled blasting is used to disturb and promote fracture penetration and increase permeability.

5. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 1, characterized in that, Step S4 is as follows: Arrange water injection wells and production wells, so that both water injection wells and production wells are connected to the fracture network formed in step S3, and establish a downhole thermal fluid circulation system and a surface thermal energy extraction system; inject low-temperature heat carrier fluid into the fracture network through water injection wells, and exchange heat with high-temperature rock mass when the fluid flows in the fracture channel, absorbing heat from the rock mass to form high-temperature fluid. High-temperature fluid flows into the production well and is lifted to the surface. During the lifting process, the potential energy provided by the high pore water pressure in the deep strata is used to compensate for the water pressure of the high-temperature fluid and help overcome the resistance of gravity lifting. After the high-temperature fluid reaches the Earth's surface, its thermal energy is extracted and utilized through a ground-based thermal energy extraction system.

6. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 5, characterized in that, The low-temperature heat transfer fluid is circulating return water that has undergone ground cooling treatment, or supplemented surface water or mine water.

7. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 5, characterized in that, The ground heat energy extraction system includes a ground heat exchanger group, a heat pump unit, a heat storage device, and a heating network; the extracted heat energy is used for heating buildings in the mining area, preheating of mine intake air, supply of industrial hot water, or geothermal power generation.

8. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 1, characterized in that, Step S5 is as follows: When the rock mass of the target block is extracted by geothermal energy in step S4 and the temperature drops below the preset safe operating temperature threshold, and the rock mass is subjected to stress-induced damage accumulation in step S2, fracture propagation in step S3, and long-term water injection thermal shock in step S4, and the degree of fragmentation reaches the preset mining requirements, a large-scale low-energy mining method is adopted to mine the ore body of the target block; the preset safe operating temperature threshold is determined according to the mine heat hazard level standard; the preset mining requirements are that the degree of rock mass fragmentation reaches the mining conditions suitable for the corresponding mining method; the large-scale low-energy mining method includes bottomless sublevel caving, staged forced caving, or backfilling mining.

9. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 1, characterized in that, It also includes multi-field monitoring and dynamic control steps throughout the entire process. During the implementation of steps S2 to S5, a microseismic monitoring system, a temperature monitoring system, and a pore water pressure monitoring system are deployed to monitor the rock mass damage evolution, temperature field changes, and water pressure distribution in real time. Based on the monitoring data, the induced engineering parameters, injection and production flow rates, and mining progress are dynamically adjusted.

10. The method for coordinated development of deep disaster-prone energy, mineral, and thermal resources based on stress induction and water pressure compensation as described in claim 9, characterized in that, The sensors of the microseismic monitoring system are installed at different depths and orientations around the target block through boreholes, forming a three-dimensional monitoring network to record the time, location, magnitude, and energy parameters of microseismic events; the probes of the temperature monitoring system are installed at different locations and depths within the fractured thermal reservoir through boreholes; and the monitoring points of the pore water pressure monitoring system are arranged in injection wells, production wells, and dedicated monitoring boreholes. The specific rules for dynamic control are as follows: when the microseismic monitoring system detects an abnormal increase in microseismic activity, indicating that the rock mass is at risk of instability, the construction progress of the induction project is suspended or slowed down, and resumed after the stress release stabilizes; When the temperature monitoring system detects a risk of thermal breakthrough in a local area, the injection and production flow rates and inter-well pressure differentials of the injection and production wells are adjusted; when the pore water pressure monitoring system detects an abnormal increase in pressure within the formation or fractured thermal reservoir, the injection pressure is reduced or the production flow rate of the production well is increased.

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