Underground carbon dioxide preposed fracturing sand injection permeability increasing and CCUS equipment and method

Abstract

The invention provides underground carbon dioxide pre-fracturing sand injection permeability increasing and CCUS equipment and method, and belongs to the technical field of energy and mineral engineering, and the equipment comprises a high-pressure pump injection system, a high-pressure sand injection system, an array type sound wave monitoring system, a gas liquefaction separation system and a main monitoring system; the high-pressure pumping system comprises a fluid high-pressure storage system and a pumping monitoring system; the method comprises the steps that all the devices are connected after drilling, the monitoring system controls pumping of high-pressure water or high-pressure acid gas fluid or solid-liquid-gas multi-phase fluid, array type sound waves are combined to monitor and regulate the rock stratum fracture form, CO2 is recycled after fracturing, and the carbon sequestration amount, the capture amount and the utilization rate are analyzed. According to the device and the method, integration of fracturing anti-reflection and carbon capture, utilization and sealing is achieved, the operation efficiency and the safety are improved, and the device and the method can be popularized to the ground to assist double-carbon target achievement and deep resource green development in the energy field.

Description

Technical Field

[0001] This invention relates to the field of energy and mining engineering technology, specifically to a carbon dioxide pre-fracturing sand injection and permeability enhancement device and method for underground mines. Background Technology

[0002] With the advancement of deep resource development, formation permeability enhancement technology has become a core support for overcoming engineering bottlenecks. The low porosity and low permeability characteristics of deep formations directly restrict the efficiency and safety of resource extraction, giving rise to a technology system centered on formation weakening. In the coal mining sector, high-gas, low-permeability coal seams have low gas extraction rates and are prone to accidents. The fracture network constructed by formation weakening can significantly improve extraction efficiency and is key to safe mining. In unconventional oil and gas extraction, shale gas and other reservoirs are tight, and formation permeability enhancement is a prerequisite for commercial mining. Weakening technologies such as hydraulic fracturing have become standard practice. In tunneling engineering, tunneling efficiency is low in hard rock formations. Pre-tunneling formation weakening treatment can significantly increase speed and shorten the construction period. High-strength roof weakening technology achieves controllable weakening by changing the mechanical properties of the roof, taking into account both support safety and resource recovery. Meanwhile, under the goal of "carbon neutrality," carbon capture, utilization, and storage (CCUS) technology has become a core direction for carbon reduction. The geological space of low-permeability coal and rock strata provides natural conditions for CO2 sequestration. Injecting CO2 into coal and rock strata to achieve integrated "permeability enhancement and carbon sequestration" has become an important path for the green transformation of industries such as coal. However, the integration of current coal and rock strata permeability enhancement technology and CCUS technology still faces many bottlenecks, making it difficult to balance permeability enhancement efficiency and carbon sequestration effect, and failing to meet the needs of safe, efficient, and green mining.

[0003] Existing technologies have several significant shortcomings. While traditional hydraulic equipment is simple and low-cost, it consumes a large amount of water, creating a significant contradiction with the water scarcity in mining areas. Furthermore, it easily triggers hydration and expansion of the coal and rock mass, leading to fracture closure, and the wastewater causes environmental pollution. CO2 fracturing, although offering advantages such as high rock-breaking efficiency and no wastewater discharge, lacks an effective fracture support mechanism. Fractures are prone to closure after depressurization, and the synergistic control technology of CO2, water, and proppant is immature. The precision of multiphase flow mixing and parameter control is insufficient, and the matching between CO2 injection parameters and coal seam fracture expansion during fracturing is poor, lacking real-time monitoring and adjustment methods. While proppant-assisted fracturing can maintain fracture conductivity, traditional systems are poorly compatible with CO2 fracturing. Insufficient proppant suspension easily leads to sand blockage, and the sand ratio adjustment lacks precise control. In terms of CCUS technology, CO2 capture and injection are disconnected, exhaust gas absorption and separation efficiency is low, there is a lack of full-process monitoring, and the sealing effect cannot be quantitatively evaluated. In terms of intelligent control, the existing system is decentralized, lacks an integrated central control platform, crack monitoring methods are limited, equipment fault early warning capabilities are weak, there is no effect analysis and feedback mechanism, and the corrosion resistance and high pressure resistance of underground equipment are insufficient, pipeline connections and sealing device sealing reliability are poor, and leakage and pressure loss are prone to occur.

[0004] The aforementioned technical bottlenecks hinder the realization of the synergistic benefits of permeability enhancement and CCUS, making the development of integrated and intelligent technologies an urgent need for the industry. This technology requires overcoming four core challenges: First, constructing a high-pressure, corrosion-resistant, multi-fluid transport and mixing system adapted to the mining environment to achieve precise proportioning and uniform mixing of supercritical CO2, water, and proppant; second, developing a dynamic monitoring and intelligent control mechanism for fractures to monitor fracture propagation in real time and optimize parameters; third, establishing a full-process monitoring and analysis system for CCUS to achieve end-to-end control of CO2 injection, absorption, separation, and storage; fourth, building an integrated intelligent control platform to integrate multiple modules for automated control and fault early warning; and fifth, utilizing single-phase or multi-phase fluids to achieve efficient perforation and uniform permeability enhancement in the reservoir. Summary of the Invention

[0005] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a coal mine pre-fracturing sand injection and permeability enhancement (CCUS) equipment and method, providing technical support for reservoir weakening and permeability enhancement and carbon sequestration.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A coal mine carbon dioxide pre-fracturing and permeability enhancement (CCUS) device includes:

[0008] The high-pressure pumping system is used to pump fluids into the formation; the high-pressure pumping system includes a high-pressure fluid storage system and a pumping monitoring system; the high-pressure fluid storage system is used to store supercritical CO2, liquid nitrogen and other acidic or neutral fluids, including a backup of supercritical CO2 gas; the pumping monitoring system is used to monitor relevant parameters and equipment operating status of the acid gas path and water path, and to provide equipment fault alarms;

[0009] The high-pressure sand injection system is used to store solid particles as proppant, adjust the sand path pressure and flow rate, control the amount of sand added, and mix the proppant and fluid in the multiphase flow mixing chamber.

[0010] An array-type acoustic monitoring system is installed inside the rock wall to analyze the state of rock fractures in real time.

[0011] A gas liquefaction and separation system is used to separate gas components from a mixed gas transported by a multiphase fluid separator and to liquefy the separated gas.

[0012] The overall monitoring system is used to monitor the parameters of each system, control the operation of each device, analyze the state of rock fractures and CCUS effects, and achieve full-process control.

[0013] Preferably, the high-pressure injection system further includes an acid gas fluid high-pressure plunger pump, an acid gas path pump outlet valve, a water tank, a high-pressure / pulse pump, a water path pump outlet valve, and a gas-liquid mixing connector; one end of the high-pressure / pulse pump is connected to the water tank, and the other end is connected to the water path pump outlet valve; one end of the acid gas fluid high-pressure plunger pump is connected to the fluid high-pressure storage system, and the other end is connected to the acid gas path pump outlet valve, the other end of which is connected to the gas-liquid mixing connector; the gas-liquid mixing connector is connected to the high-pressure sand injection system via a high-pressure anti-corrosion hose; the acid gas fluid high-pressure plunger pump, the high-pressure / pulse pump, the path pump outlet valve, and the acid gas path pump outlet valve are electrically connected to the injection monitoring system.

[0014] Preferably, the system also includes a liquefied gas storage tank, a tee, a high-pressure corrosion-resistant connector, a high-pressure corrosion-resistant tubing string, a near-hole-end high-pressure corrosion-resistant sealer, a near-hole-bottom high-pressure corrosion-resistant sealer, a high-pressure corrosion-resistant fracturing tubing string, a corrosion-resistant high-strength drill bit, a multiphase fluid absorber, and a multiphase fluid separator; the corrosion-resistant high-strength drill bit, the high-pressure corrosion-resistant fracturing tubing string, and the high-pressure corrosion-resistant tubing string are connected sequentially; the high-pressure corrosion-resistant connector is installed on the high-pressure corrosion-resistant tubing string; the high-pressure corrosion-resistant tubing string is connected to the high-pressure sand injection system; and the near-hole-bottom high-pressure corrosion-resistant sealer... The device, the high-pressure corrosion-resistant sealing device near the orifice, and the multiphase fluid absorber are fitted together and installed on top; the multiphase fluid absorber and the multiphase fluid separator are connected through a multiphase fluid transport pipeline; the multiphase fluid separator is connected to the gas liquefaction separation system through a mixed gas pipeline; the liquefied gas storage device is connected between the high-pressure fluid storage system and the gas liquefaction separation system; one end of the tee is connected to the gas-liquid mixing connector, and the other end is connected to the high-pressure sand injection system; the liquefied gas storage device and the multiphase fluid separator are electrically connected to the main monitoring system.

[0015] Preferably, the high-pressure fluid storage system includes a supercritical CO2 storage tank, a liquid nitrogen storage tank, other acidic or neutral fluid storage tanks, a CO2 outlet valve, a liquid nitrogen outlet valve, other fluid outlet valves, a total acid gas outlet valve, an acid gas pressure sensor, and an acid gas flow sensor; one end of the total acid gas outlet valve is connected to the high-pressure acid gas plunger pump, and the other end is connected to the supercritical CO2 storage tank, the liquid nitrogen storage tank, and the other acidic or neutral fluid storage tank; the CO2 outlet valve is installed in the supercritical CO2 storage tank and at the total acid gas outlet. The pipeline between the valves; the liquid nitrogen outlet valve is installed on the pipeline between the liquid nitrogen storage tank and the acid gas line main outlet valve; the other fluid outlet valve is installed on the pipeline between other acidic or neutral fluid storage tanks and the acid gas line main outlet valve; the acid gas line pressure sensor and the acid gas line flow sensor are installed on the pipeline between the acid gas line main outlet valve and the acid gas fluid high-pressure plunger pump bracket; the CO2 outlet valve, liquid nitrogen outlet valve, other fluid outlet valves, acid gas line main outlet valve, acid gas line pressure sensor, and acid gas line flow sensor are electrically connected to the pumping monitoring system.

[0016] Preferably, the high-pressure sand injection system includes a sand pressure balancing valve, a sand pressure sensor, a sand flow sensor, a high-pressure corrosion-resistant sand tank, a sand adding valve, and a multiphase flow mixing chamber; the high-pressure corrosion-resistant sand tank is provided with a sand adding port; the lower end of the high-pressure corrosion-resistant sand tank is connected to the multiphase flow mixing chamber; the sand adding valve is installed on the pipeline between the high-pressure corrosion-resistant sand tank and the multiphase flow mixing chamber; the multiphase flow mixing chamber is connected between the high-pressure corrosion-resistant connector and the tee; one end of the sand pressure balancing valve is connected to the pipeline between the multiphase flow mixing chamber and the tee, and the other end is connected to the upper end of the high-pressure corrosion-resistant sand tank; the sand pressure sensor and the sand flow sensor are connected to the pipeline between the sand pressure balancing valve and the high-pressure corrosion-resistant sand tank; the sand pressure balancing valve, the sand pressure sensor, the sand flow sensor, and the sand adding valve are electrically connected to the main monitoring system.

[0017] Preferably, the pumping monitoring system includes an acid gas path monitoring system, a water path monitoring system, and a fault alarm system.

[0018] Preferably, the overall monitoring system includes an overall acid gas path monitoring system, an overall water path monitoring system, an overall sand path monitoring system, a CCUS analysis system, a rock fracture status monitoring system, a safety monitoring system, and an effect analysis system.

[0019] Preferably, a water supply valve is installed on the water tank; the water supply valve is electrically connected to the pumping monitoring system; a main pressure sensor is installed on the tee; a main flow sensor is installed on the pipeline between the tee and the high-pressure sand injection system; the main pressure sensor and the main flow sensor are electrically connected to the main monitoring system.

[0020] Preferably, a main pressure relief valve is installed on the pipeline between the high-pressure sand injection system and the high-pressure corrosion-resistant connector; the main pressure relief valve is electrically connected to the main monitoring system.

[0021] Preferably, the multiphase fluid absorber includes an absorber tube wall and an acid gas absorption plate; the acid gas absorption plate is installed inside the absorber tube wall; the acid gas absorption plate is provided with a circular hole to accommodate the passage of the high-pressure anti-corrosion tube column; and a solid-liquid flow channel is provided inside the absorber tube wall.

[0022] A method for pre-fracturing and permeability enhancement with carbon dioxide injection and CCUS intelligent control in underground mines includes the following steps:

[0023] Step 1: Drill holes in the rock face using a directional drilling rig;

[0024] Step 2: Connect the high-pressure fluid storage system, high-pressure pumping system, high-pressure sand injection system, gas liquefaction and separation system, array-type acoustic monitoring system, pumping monitoring system, and overall monitoring system;

[0025] Step 3: Under the overall control of the monitoring system, one or more fluids are pumped into the borehole, and the state of rock fractures is monitored in real time through an array-type acoustic monitoring system, and the fracture propagation morphology is intelligently controlled.

[0026] Step 4: Absorb, separate multiphase fluids and recover CO2 after fracturing;

[0027] Step 5: Simultaneously, the monitoring system monitors and analyzes the carbon sequestration amount, capture amount, and utilization rate to achieve integrated operation of underground fracturing and permeability enhancement with carbon capture, utilization, and sequestration.

[0028] Preferably, step 3 employs a high-pressure water intelligent pumping method, specifically including:

[0029] F1. Equipment and Piping Connections: Connect the water tank to the high-pressure water pipe in the mine and install a water supply valve on the pipe. Connect the water tank to the high-pressure / pulse pump via a low-pressure hose. Connect the high-pressure / pulse pump to the water pump outlet valve via a high-pressure corrosion-resistant hose. Install a gas-liquid mixing chamber, a main pressure sensor, a main flow sensor, a main pressure relief valve, a tee, and a multiphase flow mixing chamber on the high-pressure corrosion-resistant hose. Connect the high-pressure corrosion-resistant hose to the high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is sequentially connected to a high-pressure corrosion-resistant sealing device near the borehole opening, a high-pressure corrosion-resistant fracturing tubing string, a high-pressure corrosion-resistant sealing device near the bottom of the borehole, and a corrosion-resistant high-strength drill bit. Install a multiphase fluid absorber at the borehole opening. Simultaneously, install an array-type acoustic monitoring system on the rock wall. Then connect all relevant equipment to the pump monitoring system and the main monitoring system via corresponding monitoring or monitoring lines. Connect the two systems via the pump monitoring system to the main system monitoring line.

[0030] F2. Pumping high-pressure liquid: Close the main pressure relief valve, sand circuit pressure balance valve, sand addition valve, and acid gas circuit pump outlet valve through the main monitoring system, and open the water circuit pump outlet valve. Monitor the water volume in the tank. If the water volume is less than 50%, add water to the tank through the water replenishment valve until the tank capacity reaches 90%. Monitor and adjust the water volume in the tank throughout the high-pressure water pumping process. Then, start the high-pressure / pulse pump through the main monitoring system. High-pressure water enters the high-pressure anti-corrosion hose and passes sequentially through the gas-liquid mixing chamber, main pressure sensor, main flow sensor, multiphase flow mixing chamber, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, near-hole high-pressure anti-corrosion sealer, high-pressure anti-corrosion fracturing tubing string, and near-hole bottom high-pressure anti-corrosion sealer. When passing through the near-hole high-pressure anti-corrosion sealer and near-hole bottom high-pressure anti-corrosion sealer, the water pressure does not exceed 5% of the multiphase fluid outlet pressure of the fracturing rod. During the pressure period of MPa, the capsules of the high-pressure anti-corrosion sealing device near the orifice and the high-pressure anti-corrosion sealing device near the bottom of the orifice are opened and attached to the rock wall to form a fracturing sealed space. When the water pressure exceeds 5 MPa, the multiphase fluid outlet valve of the fracturing rod is opened, and high-pressure water enters the fracturing sealed space. The water pressure acts on the rock wall. When the rock reaches the critical fracturing pressure, the rock fractures and forms hydraulic fractures.

[0031] F3. After the high-pressure water and rock interaction is completed, the high-pressure / pulse pump is shut down through the main monitoring system, and then the pressure relief valve is opened until the pressure in the pipeline is less than 0.2 MPa, at which point the fracturing is completed.

[0032] F4. Move the pipeline to the next fracturing borehole and repeat F1 to F3 to complete the regional intelligent fracturing operation.

[0033] Preferably, the entire process of implementing the high-pressure water intelligent pumping method is controlled by the central monitoring system, which controls the operation of all equipment. The array-type acoustic monitoring system monitors and inverts the crack propagation morphology in real time, and adjusts the parameters of each system to make the crack propagate along the required path.

[0034] Preferably, step 3 employs a high-pressure liquefied gas intelligent pump injection method, specifically including:

[0035] G1. Equipment and Piping Connections: Connect the supercritical CO2 storage tank, liquid nitrogen storage tank, and other acidic or neutral fluid storage tanks in parallel. The supercritical CO2 storage tank is connected to the CO2 outlet valve via a high-pressure corrosion-resistant hose. The liquid nitrogen storage tank is connected to the liquid nitrogen outlet valve via a high-pressure corrosion-resistant hose. The other acidic or neutral fluid storage tanks are connected to the outlet valves of other fluids via high-pressure corrosion-resistant hoses. Connect the multiple lines in parallel via a four-way valve. Connect the acid gas line main outlet valve, acid gas line pressure sensor, and acid gas line flow sensor sequentially via high-pressure corrosion-resistant hoses to form a high-pressure fluid storage system. The high-pressure fluid storage system is connected to the acid gas fluid high-pressure plunger pump via a low-pressure corrosion-resistant hose. The acid gas fluid high-pressure plunger pump is connected to the high-pressure... A high-pressure corrosion-resistant hose is provided, equipped with a gas-liquid mixing chamber, a main pressure sensor, a main flow sensor, a main pressure relief valve, and a multiphase flow mixing chamber. The high-pressure corrosion-resistant hose is connected to a high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is sequentially connected to a near-hole high-pressure corrosion-resistant sealing device, a high-pressure corrosion-resistant fracturing tubing string, a near-hole bottom high-pressure corrosion-resistant sealing device, and a corrosion-resistant high-strength drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock wall. All relevant equipment is then connected to the pump monitoring system and the main monitoring system via corresponding monitoring lines, and the two systems are connected to the main system monitoring line via the pump monitoring system.

[0036] G2. Pumping high-pressure acid gas fluid; close the main pressure relief valve, sand pressure balance valve, sand adding valve, and water pump outlet valve through the main monitoring system, and open the acid gas pump outlet valve and the main acid gas outlet valve; monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, a spare acid gas storage tank needs to be prepared; then, control the opening of one of the supercritical CO2 outlet valve, liquid nitrogen outlet valve, or other fluid outlet valves through the main monitoring system, while keeping the other two closed; control the start of the high-pressure plunger pump for acid gas fluid through the main monitoring system. High-pressure acid fluid or neutral gas enters the high-pressure anti-corrosion hose, passing sequentially through the tee, main pressure sensor, main flow sensor, multiphase flow mixing chamber, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, near-hole high-pressure anti-corrosion sealer, high-pressure anti-corrosion fracturing tubing string, and near-hole bottom high-pressure anti-corrosion sealer. When passing through the near-hole high-pressure anti-corrosion sealer and near-hole bottom high-pressure anti-corrosion sealer, if the acid gas fluid pressure exceeds 5... After MPa, the multiphase fluid outlet valve of the fracturing rod opens, and acidic or neutral fluid enters the fracturing confined space. The acidic and neutral fluids act on the rock wall, softening the rock wall and causing the fractures to expand again, forming a dense fracture network structure.

[0037] G3. After the interaction between the acid gas fluid and the rock is completed, the acid gas outlet valve and the main outlet valve of the acid gas line are closed sequentially through the main monitoring system. Then, the high-pressure plunger pump of the acid gas fluid is turned off. After waiting for 3 minutes, the pressure relief valve is slowly opened until the pressure in the pipeline is less than 0.15 MPa, and the fracturing is completed.

[0038] G4. Move the pipeline to the next fracturing borehole and repeat G1 to G3 to complete the regional intelligent fracturing operation.

[0039] Preferably, the entire process of the high-pressure liquefied gas intelligent pump injection method is controlled by a central monitoring system, which controls the operation of all equipment. The array-type acoustic monitoring system monitors and inverts the crack propagation morphology in real time, and adjusts the parameters of each system to make the crack propagate along the required path.

[0040] Preferably, step 3 employs a solid-liquid two-phase mixing intelligent pumping method, specifically including:

[0041] SF1, Equipment and Piping Connections: Connect the water tank to the high-pressure water pipe in the mine, and install a water supply valve on the pipe. The water tank is connected to the high-pressure / pulse pump via a low-pressure hose. The high-pressure / pulse pump is connected to the water pump outlet valve via a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant hose is equipped with a gas-liquid mixing chamber, a main pressure sensor, a main flow sensor, a high-pressure sand injection system, a main pressure relief valve, and a tee. The high-pressure sand injection system consists of a tee on the high-pressure corrosion-resistant hose; one tee connects to the multiphase flow mixing chamber, and the other connects to the sand pressure balancing valve. The sand balancing valve is connected sequentially to the sand pressure sensor, sand flow sensor, and high-pressure corrosion-resistant sand tank via the high-pressure corrosion-resistant hose. A sand-adding valve is connected to a multiphase flow mixing chamber via a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant sand tank is equipped with a sand-adding port. The high-pressure corrosion-resistant hose is connected to a high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is sequentially connected to a high-pressure corrosion-resistant sealing device near the borehole opening, a high-pressure corrosion-resistant fracturing tubing string, a high-pressure corrosion-resistant sealing device near the bottom of the borehole, and a high-strength corrosion-resistant drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock wall. All relevant equipment is then connected to the pump monitoring system and the main monitoring system via corresponding monitoring or monitoring lines. The two systems are connected to the main system monitoring line via the pump monitoring system.

[0042] SF2, high-pressure liquid pumping; close the main pressure relief valve, sand circuit pressure balancing valve, sand adding valve, and acid gas circuit pump outlet valve through the main monitoring system, open the water circuit pump outlet valve, monitor the water level in the tank, if the water level is less than 50%, add water to the tank by controlling the water replenishment valve until the tank capacity reaches 90%, monitor and adjust the water level in the tank throughout the high-pressure water pumping process; before pumping, observe the sand level in the high-pressure anti-corrosion sand tank through the main monitoring system, when the sand level is less than 50%, control the sand adding valve to open through the monitoring system until the sand level in the sand tank reaches 90%. When the pressure exceeds 90%, the sand-adding valve is closed. Then, the high-pressure / pulse pump is started via the main monitoring system. High-pressure water enters the high-pressure anti-corrosion hose and sequentially passes through the gas-liquid mixing chamber, the main pressure sensor, the main flow sensor, the multiphase flow mixing chamber, the high-pressure anti-corrosion connector, the high-pressure anti-corrosion tubing string, the near-orifice high-pressure anti-corrosion sealer, the high-pressure anti-corrosion fracturing tubing string, and the near-bottom high-pressure anti-corrosion sealer. While passing the near-orifice and near-bottom high-pressure anti-corrosion sealers, if the water pressure does not exceed 5 MPa at the multiphase fluid outlet of the fracturing rod, the capsules of the near-orifice and near-bottom high-pressure anti-corrosion sealers are opened and adhere to the rock wall, forming a closed fracturing space. When the water pressure exceeds 5 MPa, the multiphase fluid outlet valve of the fracturing rod opens, and high-pressure water enters the closed fracturing space. The water pressure acts on the rock wall, and when the rock reaches the critical fracturing pressure, the rock fractures, forming a hydraulic fracture.

[0043] SF3 is pumped into a solid-liquid two-phase mixture. After a period of high-pressure fluid pumping, the pipeline pressure is reduced to 6-8 MPa. Then, the sand pressure balancing valve is opened, and the sand addition valve opening is slowly adjusted through the main monitoring system. The sand injection ratio is calculated based on the reduction in sand volume. Solid particles and high-pressure liquid mix in the multiphase flow mixing chamber to form a solid-liquid two-phase fluid. The solid-liquid two-phase flow passes through a high-pressure anti-corrosion hose, a high-pressure anti-corrosion connector, a high-pressure anti-corrosion tubing string, a high-pressure anti-corrosion seal near the wellhead, a high-pressure anti-corrosion fracturing tubing string, and a high-pressure anti-corrosion seal near the bottom of the well. When passing through the high-pressure anti-corrosion fracturing tubing string, it enters the fracturing sealed space through the fracturing rod multiphase flow outlet, and then enters the liquid fracturing fracture, further expanding the fracture to form a dense fracture network, supporting the fracture, reducing fracture aperture changes, and maintaining high fracture conductivity.

[0044] After the interaction of SF4 and solid-liquid two-phase flow with the rock is completed, the sand injection valve is slowly closed by controlling the main monitoring system. After the sand injection valve is closed for 3 minutes, the high-pressure / pulse pump is closed by controlling the main monitoring system, and then the pressure relief valve is opened until the pressure in the pipeline is less than 0.25 MPa, and the fracturing is completed.

[0045] SF5. Move the pipeline to the next fracturing borehole and repeat SF1 to SF4 to complete the regional intelligent fracturing operation.

[0046] Preferably, the solid-liquid two-phase mixing intelligent pumping method is implemented throughout the entire process, with the operation of all equipment controlled by the central monitoring system, and the array-type acoustic monitoring system monitoring and inverting the crack propagation morphology in real time, adjusting the parameters of each system to make the crack propagate along the required path.

[0047] Preferably, step 3 employs a solid-gas two-phase mixing intelligent pumping method, specifically including:

[0048] SG1. Equipment and Piping Connections: Supercritical CO2 storage tanks, liquid nitrogen storage tanks, and other acidic or neutral fluid storage tanks are connected in parallel. The supercritical CO2 storage tank is connected to the CO2 outlet valve via a high-pressure corrosion-resistant hose. The liquid nitrogen storage tank is connected to the liquid nitrogen outlet valve via a high-pressure corrosion-resistant hose. Other acidic or neutral fluid storage tanks are connected to other fluid outlet valves via high-pressure corrosion-resistant hoses. Multiple lines are connected in parallel via a four-way valve. The acid gas path main outlet valve, acid gas path pressure sensor, and acid gas path flow sensor are sequentially connected via high-pressure corrosion-resistant hoses to form a high-pressure fluid storage system. The high-pressure fluid storage system is connected to an acid gas fluid high-pressure plunger pump via a low-pressure corrosion-resistant hose. The acid gas fluid high-pressure plunger pump is connected to a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant hose is equipped with a gas-liquid mixing chamber, a main pressure sensor, a main flow sensor, a high-pressure sand injection system, a main pressure relief valve, and a three-way valve. The high-pressure sand injection system is... A tee is installed on the high-pressure corrosion-resistant hose. One tee connects to the multiphase flow mixing chamber, and the other connects to the sand path pressure balancing valve. The sand path balancing valve is connected in sequence to the sand path pressure sensor, sand path flow sensor, high-pressure corrosion-resistant sand tank, and sand adding valve via the high-pressure corrosion-resistant hose. The sand adding valve is connected to the multiphase flow mixing chamber via the high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant sand tank is equipped with a sand adding port. The high-pressure corrosion-resistant hose is connected to the high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is connected in sequence to the high-pressure corrosion-resistant sealing device near the borehole opening, the high-pressure corrosion-resistant fracturing tubing string, the high-pressure corrosion-resistant sealing device near the bottom of the borehole, and the corrosion-resistant high-strength drill bit. A multiphase fluid absorber is installed at the borehole opening. At the same time, an array-type acoustic monitoring system is installed on the rock wall. Then, all relevant equipment is connected to the pump monitoring system and the main monitoring system via corresponding monitoring or monitoring lines. The two systems are connected to the main system monitoring line through the pump monitoring system.

[0049] SG2. Pump high-pressure acid gas fluid; close the main pressure relief valve, sand circuit pressure balancing valve, sand adding valve, and water circuit pump outlet valve through the main monitoring system, and open the acid gas circuit pump outlet valve and the acid gas circuit main outlet valve; monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, a spare acid gas storage tank should be prepared; in addition, before pumping, observe the sand storage volume in the high-pressure anti-corrosion sand tank through the main monitoring system. When the sand storage volume is less than 50%, control the sand adding valve to open through the monitoring system until the sand volume in the sand tank exceeds 90%, then close the sand adding valve; then, control the opening of the supercritical CO2 outlet valve through the main monitoring system. One of the liquid nitrogen outlet valves or other fluid outlet valves is the acid gas outlet valve, while the other two are closed. The high-pressure plunger pump for acid gas fluid is started by controlling the main monitoring system. High-pressure acid fluid or neutral gas enters the high-pressure anti-corrosion hose and passes sequentially through the gas-liquid mixing chamber, the main pressure sensor, the main flow sensor, the multiphase flow mixing chamber, the high-pressure anti-corrosion connector, the high-pressure anti-corrosion tubing string, the high-pressure anti-corrosion seal near the wellhead, the high-pressure anti-corrosion fracturing tubing string, and the high-pressure anti-corrosion seal near the bottom of the well. When the acid gas fluid pressure exceeds 5 MPa after passing through the high-pressure anti-corrosion seal near the wellhead and the high-pressure anti-corrosion seal near the bottom of the well, the multiphase fluid outlet valve of the fracturing rod opens, and the acid or neutral fluid enters the fracturing sealed space. The acid and neutral fluids act on the rock wall, softening the rock wall and causing the fractures to expand again, forming a dense fracture network structure.

[0050] SG3. Pumping solid-liquid two-phase mixture: After pumping acid gas fluid for a period of time, the pipeline pressure is reduced to 6-8 MPa. Then, the sand pressure balance valve is opened, and the sand addition valve opening is slowly adjusted through the main monitoring system. The sand injection ratio is calculated based on the sand reduction. Solid particles and high-pressure acid gas fluid are mixed in the multiphase flow mixing chamber to form a solid-gas two-phase fluid. The solid-gas two-phase flow passes through high-pressure anti-corrosion hose, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, high-pressure anti-corrosion sealer near the wellhead, high-pressure anti-corrosion fracturing tubing string, and high-pressure anti-corrosion sealer near the bottom of the well. When passing through the high-pressure anti-corrosion fracturing tubing string, it enters the fracturing sealed space through the multiphase flow outlet of the fracturing rod, and then enters the acid gas fluid fracturing fracture, further expanding the fracture to form a dense fracture network, supporting the fracture, reducing the change in fracture opening, and maintaining the high conductivity of the fracture.

[0051] After the interaction between the solid-gas two-phase fluid and the rock is completed, the sand pressure balance valve and sand addition valve are closed sequentially through the main monitoring system. After 3 minutes, the acid gas outlet valve and the main outlet valve of the acid gas line are closed sequentially through the main monitoring system. Then, the acid gas fluid high-pressure plunger pump is turned off. After another 3 minutes, the pressure relief valve is slowly opened until the pressure in the pipeline is less than 0.25 MPa, and the fracturing is completed.

[0052] SG5. Move the pipeline to the next fracturing borehole and repeat SG1 to SG4 to complete the regional intelligent fracturing operation.

[0053] Preferably, the solid-gas two-phase mixing intelligent pumping method is implemented throughout the entire process, with the operation of all equipment controlled by the central monitoring system, and the array-type acoustic monitoring system monitoring and inverting the crack propagation morphology in real time, adjusting the parameters of each system to make the crack propagate along the required path.

[0054] Preferably, step 3 employs a solid-liquid-gas multiphase mixing intelligent pumping method, specifically including:

[0055] SFG1, Equipment and Piping Connections: Connect the supercritical CO2 storage tank, liquid nitrogen storage tank, and other acidic or neutral fluid storage tanks in parallel. The supercritical CO2 storage tank is connected to the CO2 outlet valve via a high-pressure corrosion-resistant hose. The liquid nitrogen storage tank is connected to the liquid nitrogen outlet valve via a high-pressure corrosion-resistant hose. Other acidic or neutral fluid storage tanks are connected to the outlet valves of other fluids via high-pressure corrosion-resistant hoses. Connect the multiple lines in parallel using a four-way valve. Then, sequentially connect the acid gas path main outlet valve, acid gas path pressure sensor, and acid gas path flow meter via high-pressure corrosion-resistant hoses. Sensors form a high-pressure fluid storage system; the high-pressure fluid storage system is connected to a high-pressure plunger pump for acid gas fluid via a low-pressure corrosion-resistant hose, and the high-pressure plunger pump for acid gas fluid is connected to a high-pressure corrosion-resistant hose; a water tank is connected to a high-pressure water pipe in the mine, and a water supply valve is installed on the pipeline; the water tank is connected to a high-pressure / pulse pump via a low-pressure hose, and the high-pressure / pulse pump is connected to the outlet valve of the water pump via a high-pressure corrosion-resistant hose; the outlet valves of the water pump and the acid gas pump are connected to a gas-liquid mixing chamber via high-pressure corrosion-resistant hoses, and then connected to high-pressure corrosion-resistant hoses. Subsequently, a main pressure sensor, a main flow sensor, a high-pressure sand injection system, and a main pressure relief valve are installed on the high-pressure corrosion-resistant hose. The high-pressure sand injection system consists of a tee valve on the high-pressure corrosion-resistant hose, one branch connecting to the multiphase flow mixing chamber and the other to the sand pressure balancing valve. The sand balancing valve is connected sequentially to the sand pressure sensor, sand flow sensor, high-pressure corrosion-resistant sand tank, and sand adding valve via the high-pressure corrosion-resistant hose. The sand adding valve is connected to the multiphase flow mixing chamber via the high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant sand tank is equipped with a sand adding port. The high-pressure corrosion-resistant hose is connected to the high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is then sequentially connected to the high-pressure corrosion-resistant sealing device near the borehole opening, the high-pressure corrosion-resistant fracturing tubing string, the high-pressure corrosion-resistant sealing device near the bottom of the borehole, and the corrosion-resistant high-strength drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock wall. All relevant equipment is then connected to the pump monitoring system and the main monitoring system via corresponding monitoring lines. The two systems are then connected to the main system monitoring line via the pump monitoring system.

[0056] SFG2, pumping high-pressure acid gas fluid; close the main pressure relief valve, sand pressure balance valve, and sand adding valve through the main monitoring system, and open the acid gas pump outlet valve, acid gas main outlet valve, and water pump outlet valve; monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, a spare acid gas storage tank should be prepared; monitor the water volume in the water tank. If the water volume is less than 50%, add water to the water tank by controlling the water replenishment valve until it reaches 90% of the water tank capacity. Monitor and adjust the water volume in the water tank throughout the high-pressure water pumping process; in addition, before pumping, observe the sand storage in the high-pressure anti-corrosion sand tank through the main monitoring system. When the sand storage is less than 50%, control the sand adding valve to open through the monitoring system until the sand volume in the sand tank exceeds 90%, and then close the sand adding valve;

[0057] Next, the main monitoring system controls the opening of one of the following acid gas outlet valves: supercritical CO2 outlet valve, liquid nitrogen outlet valve, or other fluid outlet valves, while the other two remain closed. The main monitoring system also controls the start of the high-pressure plunger pump for acid gas, allowing high-pressure acidic fluid or neutral gas to enter the high-pressure anti-corrosion hose. Simultaneously, the main monitoring system controls the start of the high-pressure / pulse pump, allowing high-pressure water to enter the high-pressure anti-corrosion hose. The gas and liquid phases are mixed in the gas-liquid mixing chamber. The two-phase fluid then enters the high-pressure anti-corrosion hose, passing sequentially through the tee, main pressure sensor, main flow sensor, multiphase mixing chamber, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, near-hole high-pressure anti-corrosion sealer, high-pressure anti-corrosion fracturing tubing string, and near-hole bottom high-pressure anti-corrosion sealer. When the pressure of the two-phase fluid exceeds 5... After MPa, the multiphase fluid outlet valve of the fracturing rod opens, and the gas-liquid two-phase fluid enters the fracturing confined space. The gas-liquid two-phase fluid acts on the rock wall, softening the rock wall and causing the cracks to expand again, forming a dense fracture network structure.

[0058] SFG3: Pumping a solid-liquid-gas multiphase mixture; after pumping the gas-liquid two-phase fluid for a period of time, reduce the pipeline pressure to 6-8 MPa, then open the sand pressure balancing valve, and slowly adjust the sand addition valve opening through the main monitoring system, calculating the injection sand ratio based on the sand reduction; solid particles and high-pressure gas-liquid two-phase fluid are mixed in the multiphase flow mixing chamber to form a solid-liquid-gas multiphase fluid; the solid-liquid-gas multiphase fluid passes through high-pressure anti-corrosion hoses, high-pressure anti-corrosion connectors, high-pressure anti-corrosion tubing, near-hole high-pressure anti-corrosion sealing device, high-pressure anti-corrosion fracturing tubing, and near-hole bottom high-pressure anti-corrosion sealing device; when passing through the high-pressure anti-corrosion fracturing tubing, it enters the fracturing sealed space through the fracturing rod multiphase flow outlet, and then enters the gas-liquid two-phase fluid fracturing fracture, further expanding the fracture, forming a dense fracture network, supporting the fracture, reducing fracture opening changes, and maintaining the high conductivity of the fracture;

[0059] After the interaction of SFG4, solid-liquid-gas multiphase fluid, and rock is completed, the sand pressure balance valve and sand addition valve are closed sequentially through the main monitoring system. After 3 minutes, the acid gas outlet valve and the main outlet valve of the acid gas line are closed sequentially through the main monitoring system. Then, the acid gas fluid high-pressure plunger pump and high-pressure / pulse pump are turned off. After another 3 minutes, the pressure relief valve is slowly opened until the pressure in the pipeline is less than 0.3 MPa, and the fracturing is completed.

[0060] SFG5: Move the pipeline to the next fracturing borehole and repeat SG1 to SG4 to complete the regional intelligent fracturing operation.

[0061] Preferably, the solid-liquid-gas multiphase mixing intelligent pumping method is implemented throughout the entire process, with the operation of all equipment controlled by the central monitoring system, and the array-type acoustic monitoring system monitoring and inverting the crack propagation morphology in real time, adjusting the parameters of each system to make the crack propagate along the required path.

[0062] Preferably, in step 3, the method for intelligently controlling the crack propagation morphology includes:

[0063] 1) Unidirectional crack control to crack network expansion: When monitoring shows that the crack is expanding in a single direction, if only water is injected, increase the pulsation frequency of the water injection. Through the pulsating effect of the water flow, fatigue damage is formed on the crack surface, thereby breaking the control of the ground stress and forming microcracks on the inner wall of the crack. After the microcracks are formed, observe the cracks to start expanding. When the amplitude of the expansion length change decreases, reduce the water injection frequency and increase the discharge rate. Use high discharge rate to impact the microcracks, causing the microcracks to expand and form a crack network. If the effect is still not good, the frequency can be adjusted multiple times to allow the crack network to develop fully.

[0064] 2) The crack network is controlled to be unidirectional crack propagation; when the monitoring and inversion show that the crack propagation is multidirectional crack network, such as only water injection, the fluid pressure and frequency are gradually reduced, and the crack direction is observed to gradually change from multidirectional to unidirectional. By reducing the water pressure and flow range, the crack is made to propagate only along the most easily propagating direction, and then the crack propagation direction is adjusted to maintain the crack propagation direction.

[0065] 3) Fracture network boundary control methods: ① If it is necessary to control the fractures from intersecting, and only through seepage migration, when the distance between the fracture network and the previous fracture network is 1m, reduce the fluid pressure and flow rate to stop the fractures from extending further. Increase the number of fractures within the existing fracture network only through low-volume, high-frequency pulsation. A small amount of solid can also be added to block micro-fractures, reduce fracture filtration efficiency, and improve the overall permeability of the area, thereby increasing production. ② When it is necessary to control the fractures from intersecting, allowing the fracture network to connect, once the fracture network is connected, the fluid pressure does not need to overcome the tensile strength of the rock, thus gradually decreasing, causing the fractures to expand slowly or even stop. At this time, there are fewer fractures at the fracture network boundary. It is necessary to increase the pulsation frequency and flow rate to ensure that the fluid loss is less than the injection volume, thereby promoting the expansion of the fracture network at the boundary, improving the permeability of the two borehole sections, and thus improving the flow conductivity of the fracture network. If the fracture network effect monitored by acoustic signals is still not ideal, the proportion of solid in the fluid can be increased to block micro-fracture channels, reduce fluid loss, increase fluid resistance, and thus allow the fracture network to develop more fully.

[0066] 4) Initial weakening of the fracture network: In the early stage of fracture propagation, in order to make the fractures propagate evenly in multiple directions, acidic fluid can be injected into the fractures for a period of time to weaken the rock layer and reduce the strength of the rock layer. Through the phase change of the gas, a relatively dense fracture network is formed in the closed section. Then, high-volume fracturing is carried out, combined with sand addition, to achieve the purpose of fully developing the fracture network.

[0067] Preferably, in step 5, the CCUS intelligent monitoring method is used to monitor and analyze carbon sequestration, capture, and utilization rates, specifically including:

[0068] The carbon content change (Q1) in the high-pressure fluid storage system is monitored by the overall monitoring system; the absorption rate (Q2) of the multiphase fluid absorber is monitored by the absorber monitoring line; and the CO2 content (Q3) and other carbon contents (Q4) separated from the mixed gas are monitored by the gas liquefaction separation system monitoring line. The carbon sequestration amount, capture amount, and utilization rate are calculated, with the carbon sequestration amount being Q. C = Q1 - Q2 - Q3, carbon capture amount is Q B = Q2 + Q4, carbon utilization rate is Q L =1-(Q2+ Q3) / Q1.

[0069] Preferably, when injecting acidic gas fluid into the borehole, the gas flowing out or seeping into the borehole is recovered. Specifically, this includes: for acidic gas, at the borehole opening, some gas is first absorbed by an acidic gas absorption plate, and the remaining gas and solid-liquid multiphase fluid enter the multiphase fluid transport pipeline and reach the multiphase fluid separator. In the separator, solids settle at the bottom, followed by liquids, and then gases. A solid-liquid discharge valve is installed at the bottom of the multiphase fluid separator. When the overall monitoring system detects that the liquid level in the separator reaches 70% of the total separator volume, the lower solid-liquid discharge valve is opened to discharge the solid-liquid fluid. When the liquid level reaches 10% of the total separator volume, the lower solid-liquid discharge valve is closed. A gas pipeline is connected to the top of the multiphase fluid separator to deliver the gas to a gas liquefaction separation system. The gas liquefaction separation system then separates the multiple components in the mixed gas. The liquefied gas or supercritical gas is then stored in the corresponding liquefied gas storage tank, and then the liquefied gas or supercritical gas is injected into the acidic gas fluid storage tank for recycling.

[0070] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0071] 1. This invention designs a CO2 pre-fracturing sand injection and permeability enhancement and CCUS intelligent control equipment for underground mines, and provides an intelligent control method for CO2 pre-fracturing sand injection, realizing an integrated intelligent control process of "fracturing and permeability enhancement - CCUS" in underground mines, solving the coordination problem of the two operating independently in the past.

[0072] 2. This invention provides an intelligent pumping method for six types of fluids, including liquid phase, acid gas fluid, solid-liquid two-phase flow, solid-gas two-phase flow, gas-liquid two-phase flow, and solid-liquid-gas multiphase flow, and clarifies the control parameters for each fluid, breaking through the limitation of the single type of traditional fracturing fluid.

[0073] 3. The present invention designs a pumping monitoring system (including acid gas path monitoring, water path monitoring, and fault alarm modules) and a central monitoring system to form a dual control architecture. The central monitoring system can observe and control the operation of the pumping system in real time, and at the same time realize timely early warning of equipment failure, greatly improving the system's safety redundancy.

[0074] 4. This invention provides a method for intelligent control of rock fracture morphology, including unidirectional fracture control to fracture network expansion, fracture network control to unidirectional fracture expansion, fracture network boundary control, and initial weakening of the fracture network. The fracture morphology is inverted by an array-type acoustic monitoring system, and the direction and morphology of fracture expansion are intelligently adjusted by a total monitoring system.

[0075] 5. This invention designs an intelligent monitoring and analysis process for carbon capture, storage and utilization, clarifies the calculation methods for carbon storage capacity, carbon capture capacity and carbon utilization rate, realizes quantitative evaluation of CCUS effect, and makes up for the lack of data support in the past.

[0076] 6. The intelligent control system of this invention includes a multiphase separation and recovery system, which separates solid, liquid and gas after fracturing through a multiphase fluid absorber (with built-in acid gas absorption plate), a multiphase fluid separator and a gas liquefaction separation system. After CO2 is liquefied, it is reinjected into the storage tank for recycling, thereby improving resource utilization and reducing emissions.

[0077] 7. The entire set of equipment of this invention (high pressure anti-corrosion hose, sealing device, drill rod, sand jar, etc.) has high pressure anti-corrosion performance and is suitable for the complex environment of high pressure and acidic fluid erosion in mines.

[0078] 8. This invention can automatically monitor the water level in the water tank and the amount of sand in the sand container. When the water level in the water tank is less than 50%, it will automatically replenish water to 90% and when the amount of sand in the sand container is less than 50%, it will automatically replenish sand to 90%, without the need for manual intervention, thus solving the problem of frequent interruptions in traditional construction due to insufficient materials.

[0079] 9. In the early stage of fracturing, the present invention injects acidic fluid to weaken the rock layer strength, and combined with the gas phase change, forms dense micro-fractures in the closed section, creating conditions for subsequent large-volume fracturing and sand addition, and improving the development density of coal seam fracture network.

[0080] 10. The overall monitoring system of this invention integrates seven major modules: overall acid gas path monitoring, overall water path monitoring, overall sand path monitoring, CCUS analysis, rock fracture status monitoring, safety monitoring, and effect analysis, to achieve full-process parameter visualization and control.

[0081] 11. After fracturing is completed, the pipeline can be moved directly to the next borehole for repeated operation without rebuilding the core system, realizing regional continuous intelligent control of fracturing operation and greatly improving the overall construction efficiency.

[0082] 12. The present invention installs a multiphase fluid absorber at the borehole opening, which preferentially absorbs overflowing acidic gases such as CO2 through an internal acidic gas absorption plate, thereby reducing the gas concentration in the work area and ensuring the breathing safety of construction personnel. Traditional fracturing lacks such protective measures.

[0083] 13. This invention fills the fractures with solid proppant in a solid-liquid-gas multiphase fluid to prevent the fractures from closing due to the elastic recoil of the rock strata after fracturing, thus maintaining the high conductivity of the fractures for a long time. Traditional CO2 fracturing in mines is prone to fracture instability due to the lack of proppant.

[0084] 14. The overall monitoring system of this invention can evaluate the fracturing effect in real time based on array-type acoustic monitoring data and CCUS data, and optimize subsequent pumping parameters, sand ratio and pressure in reverse, forming a "monitoring-analysis-optimization" closed loop. Traditional fracturing does not have a real-time feedback optimization mechanism. Attached Figure Description

[0085] Figure 1 This is a structural block diagram of the present invention;

[0086] Figure 2 This is a schematic diagram of the multiphase fluid absorber in this invention;

[0087] Figure 3 for Figure 2 Cross-sectional view along the AA direction.

[0088] in:

[0089] 1. High-pressure fluid storage system; 1-1. Supercritical CO2 storage tank; 1-2. Liquid nitrogen storage tank; 1-3. Other acidic or neutral fluid storage tanks; 1-4. CO2 outlet valve; 1-5. Liquid nitrogen outlet valve; 1-6. Other fluid outlet valves; 1-7. CO2 outlet valve monitoring line; 1-8. Liquid nitrogen outlet valve monitoring line; 1-9. Other fluid outlet valve monitoring line; 1-10. Acid gas path main outlet valve; 1-11. Acid gas path pressure sensor; 1-12. Acid gas path flow sensor; 1-13. Acid gas path main outlet valve monitoring line; 1-14. Acid gas path pressure sensor monitoring line; 1-15. Acid gas path flow sensor monitoring line;

[0090] 2. High-pressure plunger pump for acid gas fluid; 2-1. Monitoring line for high-pressure plunger pump for acid gas fluid;

[0091] 3. Acid gas pump outlet valve; 3-1. Acid gas pump outlet valve monitoring line;

[0092] 4. Water supply valve; 4-1. Water supply valve monitoring line;

[0093] 5. Water tank; 5-1. Water tank level monitoring line;

[0094] 6. High-voltage / pulse pump; 6-1. High-voltage / pulse pump monitoring line;

[0095] 7. Water pump outlet valve; 7-1. Water pump outlet valve monitoring line;

[0096] 8. Gas-liquid mixing connector; 8-1. T-junction;

[0097] 9. High-pressure corrosion-resistant hoses;

[0098] 10. Main circuit pressure sensor;

[0099] 11. Total flow sensor;

[0100] 12. High-pressure sand injection system; 12-1. Sand circuit pressure balancing valve; 12-2. Sand circuit pressure sensor; 12-3. Sand circuit flow sensor; 12-4. High-pressure corrosion-resistant sand tank; 12-5. Sand adding valve; 12-6. Multiphase flow mixing chamber; 12-7. Sand adding port; 12-8. Sand circuit pressure balancing valve monitoring line; 12-9. Sand circuit pressure sensor detection line; 12-10. Sand circuit flow sensor monitoring line; 12-11. Sand adding valve monitoring line; 12-12. Sand quantity monitoring line; 12-13. Sand adding port monitoring line;

[0101] 13. Main pressure relief valve; 13-1. Main pressure relief valve monitoring line;

[0102] 14. High-pressure corrosion-resistant connector;

[0103] 15. High-pressure corrosion-resistant tubing;

[0104] 16. High-pressure corrosion-resistant borehole sealer near the orifice;

[0105] 17. High-pressure corrosion-resistant borehole sealer near the bottom of the hole;

[0106] 18. High-pressure corrosion-resistant fracturing tubing string; 18-1. High-pressure corrosion-resistant fracturing tubing string multiphase flow outlet;

[0107] 19. Corrosion-resistant, high-strength drill bit;

[0108] 20. Rock wall; 20-1. Array-type acoustic wave monitoring system; 20-2. Monitoring line of array-type acoustic wave monitoring system;

[0109] 21. Multiphase fluid absorber; 21-1. Acid gas absorption plate; 21-2. Absorber monitoring line; 21-3. Absorber tube wall; 21-4. Solid-liquid flow channel;

[0110] 22. Multiphase fluid transport pipelines;

[0111] 23. Multiphase fluid separator; 23-1. Multiphase fluid separator monitoring line;

[0112] 24. Mixed gas pipeline;

[0113] 25. Gas liquefaction and separation system; 25-1. Monitoring line for gas liquefaction and separation system;

[0114] 26. Liquefied petroleum gas (LPG) storage unit; 26-1. LPG storage unit monitoring line;

[0115] 27. Pumping monitoring system; 27-1. Acid gas path monitoring system; 27-2. Water path monitoring system; 27-3. Fault alarm system; 27-4. Pumping monitoring system to main system monitoring line;

[0116] 28. Overall monitoring system; 28-1. Overall acid gas path monitoring system; 28-2. Overall water path monitoring system; 28-3. Overall sand path monitoring system; 28-4. CCUS analysis system; 28-5. Rock stratum fracture status monitoring system; 28-6. Safety monitoring system; 28-7. Effect analysis system. Detailed Implementation

[0117] The invention will now be further described with reference to the accompanying drawings.

[0118] like Figures 1 to 3 As shown, a CO2 pre-fracturing and permeability enhancement (CCUS) device for mines includes a high-pressure fluid storage system 1, a high-pressure acid gas plunger pump 2, an acid gas pump outlet valve 3, a water supply valve 4, a water tank 5, a high-pressure / pulse pump 6, a water pump outlet valve 7, a gas-liquid mixing connector 8, a tee 8-1, a high-pressure corrosion-resistant hose 9, a main pressure sensor 10, a main flow sensor 11, a high-pressure sand injection system 12, a main pressure relief valve 13, a high-pressure corrosion-resistant connector 14, a high-pressure corrosion-resistant tubing string 15, a near-hole high-pressure corrosion-resistant sealing device 16, a near-hole bottom high-pressure corrosion-resistant sealing device 17, a high-pressure corrosion-resistant fracturing tubing string 18, a corrosion-resistant high-strength drill bit 19, a rock wall 20, a multiphase fluid absorber 21, a multiphase fluid transport pipeline 22, a multiphase fluid separator 23, a mixed gas pipeline 24, a gas liquefaction separation system 25, a liquefied gas storage tank 26, a pumping monitoring system 27, and a main monitoring system 28.

[0119] The high-pressure fluid storage system 1 includes: a supercritical CO2 storage tank 1-1, a liquid nitrogen storage tank 1-2, other acidic or neutral fluid storage tanks 1-3 (e.g., low-concentration hydrochloric acid, sulfuric acid, etc.), a CO2 outlet valve 1-4, a liquid nitrogen outlet valve 1-5, other fluid outlet valves 1-6, a CO2 outlet valve monitoring line 1-7, a liquid nitrogen outlet valve monitoring line 1-8, other fluid outlet valve monitoring lines 1-9, a total acid gas outlet valve 1-10, an acid gas pressure sensor 1-11, an acid gas flow sensor 1-12, a total acid gas outlet valve monitoring line 1-13, an acid gas pressure sensor monitoring line 1-14, and an acid gas flow sensor monitoring line 1-15.

[0120] The acid gas fluid high-pressure plunger pump 2 is connected to the pumping monitoring system 27 via the acid gas fluid high-pressure plunger pump monitoring line 2-1 to monitor the start and stop of the acid gas fluid high-pressure plunger pump 2 and pump the fluid in the high-pressure fluid storage system into the formation.

[0121] The acid gas pump outlet valve 3 is connected to the pumping monitoring system 27 via the acid gas pump outlet valve monitoring line 3-1 to monitor the opening and closing status of the acid gas pump outlet valve 3.

[0122] The water supply valve 4 is connected to the pump monitoring system 27 via the water supply valve monitoring line 4-1 to monitor the opening degree of the water supply valve 4.

[0123] Water tank 5 is connected to pump monitoring system 27 via water tank level monitoring line 5-1 to monitor changes in water level inside water tank 5.

[0124] The high-pressure / pulse pump 6 is connected to the pumping monitoring system 27 via the high-pressure / pulse pump monitoring line 6-1 to monitor the start and stop of the high-pressure / pulse pump 6 and pump high-pressure water into the formation at a horizontal or variable flow rate.

[0125] The water pump outlet valve 7 is connected to the pump injection monitoring system 27 via the water pump outlet valve monitoring line 7-1 to monitor the opening and closing status of the water pump outlet valve 7.

[0126] The high-pressure sand injection system 12 includes a sand pressure balancing valve 12-1, a sand pressure sensor 12-2, a sand flow sensor 12-3, a high-pressure corrosion-resistant sand tank 12-4, a sand adding valve 12-5, a multiphase flow mixing chamber 12-6, a sand adding port 12-7, a sand pressure balancing valve monitoring line 12-8, a sand pressure sensor detection line 12-9, a sand flow sensor monitoring line 12-10, a sand adding valve monitoring line 12-11, a sand quantity monitoring line 12-12, and a sand adding port monitoring line 12-13.

[0127] The sand circuit pressure balancing valve 12-1 is connected to the main monitoring system 28 via the sand circuit pressure balancing valve monitoring line 12-8 to monitor the opening and closing status of the sand circuit pressure balancing valve 12-1.

[0128] The sand pressure sensor 12-2 is connected to the main monitoring system 28 via the sand pressure sensor monitoring line 12-9 to monitor the sand pressure.

[0129] The sand flow sensor 12-3 is connected to the main monitoring system 28 via the sand flow sensor monitoring line 12-10 to monitor the sand flow.

[0130] The sand filling valve 12-5 is connected to the main monitoring system 28 via the sand filling valve monitoring line 12-11 to monitor the opening degree of the sand filling valve 12-5.

[0131] The high-pressure corrosion-resistant sand tank 12-4 is connected to the main monitoring system 28 via the sand quantity monitoring line 12-12 to monitor the sand quantity inside the sand tank.

[0132] The sand filling port 12-7 is connected to the main monitoring system 28 via the sand filling port monitoring line 12-13 to monitor the opening degree of the sand filling port 12-7.

[0133] The main pressure relief valve 13 is connected to the main monitoring system 28 via the main pressure relief valve monitoring line 13-1 to monitor the opening and closing status of the pressure relief valve.

[0134] The high-pressure corrosion-resistant fracturing string 18 is equipped with a multiphase flow outlet for passing through a multiphase mixture of solid, liquid, and gaseous fluids.

[0135] An array-type acoustic wave monitoring system 20-1 is installed inside the rock wall 20, and is connected to the main monitoring system 28 through the monitoring line 20-2 of the array-type acoustic wave monitoring system to analyze the state of rock fractures in real time.

[0136] The multiphase fluid absorber 21 is equipped with an acid gas absorption plate 21-1 for absorbing acid gases such as CO2. At the same time, it is connected to the main monitoring system 28 through the absorber monitoring line 21-2 to monitor information such as the flow rate of each phase of the multiphase fluid passing through the absorber.

[0137] The gas liquefaction and separation system 25 is connected to the main monitoring system via the gas liquefaction and separation system monitoring line 25-1 to monitor the gas composition and flow rate.

[0138] The LPG storage device is connected to the main monitoring system via the LPG storage device monitoring line to monitor the remaining LPG level.

[0139] The pumping monitoring system 27 mainly consists of three modules: the acid gas path monitoring system 27-1, the water path monitoring system 27-2, and the fault alarm system 27-3. The main monitoring system 28 can observe the status of the pumping monitoring system 27 and control its operation through the main system monitoring line 27-4.

[0140] The overall monitoring system 28 includes the overall acid gas path monitoring system 28-1, the overall water path monitoring system 28-2, the overall sand path monitoring system 28-3, the CCUS analysis system 28-4, the rock stratum fracture status monitoring system 28-5, the safety monitoring system 28-6, and the effect analysis system 28-7.

[0141] The underground CO2 pre-fracturing sand injection permeability enhancement and CCUS intelligent control method includes seven main methods, namely, high-pressure water intelligent pumping method, high-pressure liquefied gas intelligent pumping method, solid-liquid two-phase mixed intelligent pumping method, solid-gas two-phase mixed intelligent pumping method, solid-liquid-gas multi-phase mixed intelligent pumping method, rock fracture morphology intelligent control method, and CCUS intelligent monitoring method.

[0142] (1) High-pressure water intelligent pumping method

[0143] The equipment involved mainly includes: water tank 5, high pressure / pulse pump 6, water pump outlet valve 7, gas-liquid mixing connector 8, high pressure anti-corrosion hose 9, main pressure sensor 10, main flow sensor 11, main pressure relief valve 13, high pressure anti-corrosion connector 14, high pressure anti-corrosion tubing string 15, high pressure anti-corrosion sealing device near the borehole opening 16, high pressure anti-corrosion sealing device near the bottom of the borehole 17, high pressure anti-corrosion fracturing tubing string 18, anti-corrosion high-strength drill bit 19, rock wall 20, array-type acoustic monitoring system 20-1, multiphase fluid absorber 21, pumping monitoring system 27, main monitoring system 28, and corresponding monitoring lines, etc.

[0144] Includes the following steps:

[0145] F1. Drilling. Using a directional drilling rig, drill holes of the required dimensions (diameter, angle, length, etc.) into the rock face at a depth of 20 mm.

[0146] F2. Equipment and Piping Connections. Connect water tank 5 to the high-pressure water pipe in the mine, and install a water supply valve 4 on the pipeline. Water tank 5 is connected to high-pressure / pulse pump 6 through a low-pressure hose. High-pressure / pulse pump 6 is connected to water pump outlet valve 7 through high-pressure anti-corrosion hose 9. The high-pressure anti-corrosion hose 9 is equipped with a gas-liquid mixing connector 8, a main pressure sensor 10, a main flow sensor 11, a main pressure relief valve 13, a tee 8-1, a multiphase flow mixing chamber 12-6, etc. The high-pressure anti-corrosion hose 9 is connected to high-pressure anti-corrosion tubing string 15 through high-pressure anti-corrosion connector 14. The high-pressure anti-corrosion tubing string 15 is sequentially connected to a high-pressure anti-corrosion sealing device 16 near the borehole opening, a high-pressure anti-corrosion fracturing tubing string 18, a high-pressure anti-corrosion sealing device 17 near the bottom of the borehole, and an anti-corrosion high-strength drill bit 19. A multiphase fluid absorber 21 is installed at the borehole opening. At the same time, an array-type acoustic monitoring system 20-1 is installed on the rock wall 20, and then all relevant equipment is connected to the pumping monitoring system 27 and the main monitoring system 28 through corresponding monitoring or monitoring lines, and the two systems are connected to the main system monitoring line 27-4 through the pumping monitoring system.

[0147] F3. Pumping high-pressure liquid. After the equipment and pipeline connections are completed, close the main pipeline pressure relief valve 13, sand pipeline pressure balancing valve 12-1, sand adding valve 12-5, and acid gas pipeline pump outlet valve 3 through the main monitoring system, and open the water pipeline pump outlet valve 7. Monitor the water level in the water tank. If the water level is less than 50%, add water to the water tank 5 by controlling the water replenishment valve 4 until the water tank capacity reaches 90%. Monitor and adjust the water level in the tank throughout the high-pressure water pumping process. Next, the high-pressure / pulse pump 6 is started via the main monitoring system 28. High-pressure water enters the high-pressure anti-corrosion hose and passes sequentially through the gas-liquid mixing connector 8, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the near-hole high-pressure anti-corrosion sealer 16, the high-pressure anti-corrosion fracturing tubing string 18, and the near-bottom high-pressure anti-corrosion sealer 17. When the water pressure does not exceed the pressure (5 MPa) at the multiphase fluid outlet 18-1 of the fracturing rod, the capsules of the near-hole high-pressure anti-corrosion sealer 16 and the near-bottom high-pressure anti-corrosion sealer 17 are opened and adhere to the rock wall 20, forming a fracturing sealed space. When the water pressure exceeds 5 MPa... After MPa, the multiphase fluid outlet valve of the fracturing rod opens, and high-pressure water enters the fracturing confined space. The water pressure acts on the rock wall, and when the rock reaches the critical fracturing pressure, the rock fractures, forming hydraulic fractures.

[0148] F4. After the high-pressure water and rock interaction is completed, the high-pressure / pulse pump 6 is shut down through the main monitoring system 28, and then the pressure relief valve is opened until the pressure in the pipeline is less than 0.2 MPa, at which point the fracturing is completed.

[0149] F5. Move the pipeline to the next fracturing borehole and repeat S1-S4 to complete the regional intelligent fracturing operation.

[0150] The entire process of high-pressure water fracturing of rocks is controlled by a central monitoring system through the monitoring lines of each device. The array-type acoustic wave monitoring system 20-1 monitors and inverts the crack propagation morphology in real time, providing a basis for the formation of dense cracks. The system also adjusts the parameters of each system through an intelligent system to make the cracks propagate along the required path.

[0151] (2) Intelligent pump injection of high-pressure liquefied gas

[0152] The equipment involved mainly includes: high-pressure fluid storage system, high-pressure plunger pump for acid gas fluid, outlet valve of acid gas circuit pump, gas-liquid mixing connector, high-pressure anti-corrosion hose, main pressure sensor, main flow sensor, multiphase flow mixing chamber, main pressure relief valve, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, high-pressure anti-corrosion sealing device near the borehole orifice, high-pressure anti-corrosion sealing device near the bottom of the borehole, high-pressure anti-corrosion fracturing tubing string, anti-corrosion high-strength drill bit, rock wall, array-type acoustic monitoring system, multiphase fluid absorber, pumping monitoring system, main monitoring system, and corresponding monitoring lines, etc.

[0153] Includes the following steps:

[0154] G1. Drilling. Drilling holes of the required size (diameter, angle, length, etc.) into the rock face using a directional drilling rig.

[0155] G2. Equipment and Piping Connections. Connect the supercritical CO2 storage tank 1-1, liquid nitrogen storage tank 1-2, and other acidic or neutral fluid storage tanks 1-3 in parallel. Connect the supercritical CO2 storage tank 1-1 to the CO2 outlet valve 1-4 via a high-pressure anti-corrosion hose. Connect the liquid nitrogen storage tank 1-2 to the liquid nitrogen outlet valve 1-5 via a high-pressure anti-corrosion hose. Connect the other acidic or neutral fluid storage tanks 1-3 to the outlet valves 1-6 of other fluids via high-pressure anti-corrosion hoses. Connect the multiple lines in parallel via a four-way valve. Then, connect the acid gas main outlet valve 1-10, acid gas pressure sensor 1-11, and acid gas flow sensor 1-12 in sequence via high-pressure anti-corrosion hoses to form a high-pressure fluid storage system. The high-pressure fluid storage system is connected to the acid gas high-pressure plunger pump via a low-pressure corrosion-resistant hose. The acid gas high-pressure plunger pump is connected to a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant hose is equipped with a gas-liquid mixing connector, a main pressure sensor, a main flow sensor, a main pressure relief valve, and a multiphase flow mixing chamber. The high-pressure corrosion-resistant hose is connected to a high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is sequentially connected to a near-hole high-pressure corrosion-resistant sealing device, a high-pressure corrosion-resistant fracturing tubing string, a near-hole bottom high-pressure corrosion-resistant sealing device, and a corrosion-resistant high-strength drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock face. All relevant equipment is then connected to the pump monitoring system and the main monitoring system via corresponding monitoring lines. The two systems are connected through the pump monitoring system to the main system monitoring line.

[0156] G3. Pumping high-pressure acid gas fluid. After the equipment and pipeline connections are completed, close the main line pressure relief valve 13, sand line pressure balancing valve 12-1, sand adding valve 12-5, and water line pump outlet valve 3 through the main monitoring system. Open the acid gas line pump outlet valve 7 and the acid gas line main outlet valve 1-10. Monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, a spare acid gas storage tank needs to be prepared. Next, control the opening of one of the following acid gas outlet valves through the main monitoring system 28: supercritical CO2 outlet valve 1-4, liquid nitrogen outlet valve 1-5, or other fluid outlet valve 1-6. The other two should remain closed. The high-pressure plunger pump 2 for acid gas fluid is started by the overall monitoring system 28. High-pressure acid fluid or neutral gas enters the high-pressure anti-corrosion hose 9 and passes sequentially through the tee 8, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the high-pressure anti-corrosion sealer near the wellhead 16, the high-pressure anti-corrosion fracturing tubing string 18, and the high-pressure anti-corrosion sealer near the bottom of the well. When the acid gas fluid pressure exceeds 5 MPa after passing through the high-pressure anti-corrosion sealer near the wellhead 16 and the high-pressure anti-corrosion sealer near the bottom of the well, the multiphase fluid outlet valve of the fracturing rod opens, and the acid or neutral fluid enters the fracturing sealed space. The acid and neutral fluids act on the rock wall, softening the rock wall and causing the cracks to expand again, forming a dense network of cracks.

[0157] G4. After the interaction between the acid gas fluid and the rock is completed, the acid gas outlet valve and the acid gas line main outlet valve 1-10 are closed sequentially through the main monitoring system 28. Then, the acid gas fluid high-pressure plunger pump 2 is turned off. After waiting for 3 minutes, the pressure relief valve 13 is slowly opened until the pressure in the pipeline is less than 0.15 MPa, and the fracturing is completed.

[0158] G5. Move the pipeline to the next fracturing borehole and repeat G1-G4 to complete the regional intelligent fracturing operation.

[0159] The entire process of acid gas fluid fracturing of rock is controlled by a central monitoring system through the monitoring lines of each device. The array-type acoustic monitoring system 20-1 monitors and inverts the crack propagation morphology in real time, providing a basis for the formation of dense cracks. The system also adjusts the parameters of each system through an intelligent system to make the cracks propagate along the required path.

[0160] (3) Intelligent pumping of solid-liquid two-phase mixing

[0161] The equipment involved mainly includes: water tanks, high-pressure / pulse pumps, water pump outlet valves, gas-liquid mixing connectors, high-pressure corrosion-resistant hoses, main pressure sensors, main flow sensors, high-pressure sand injection systems, main pressure relief valves, high-pressure corrosion-resistant connectors, high-pressure corrosion-resistant tubing strings, near-hole high-pressure corrosion-resistant sealing devices, near-hole bottom high-pressure corrosion-resistant sealing devices, high-pressure corrosion-resistant fracturing tubing strings, corrosion-resistant high-strength drill bits, rock walls, array-type acoustic monitoring systems, multiphase fluid absorbers, pumping monitoring systems, main monitoring systems, and corresponding monitoring lines, etc.

[0162] Includes the following steps:

[0163] SF1. Drilling. Drilling holes of the required size (diameter, angle, length, etc.) into the rock face using a directional drilling rig.

[0164] SF2, Equipment and Piping Connections. The water tank is connected to the high-pressure water pipe in the mine, and a water supply valve is installed on the pipeline. The water tank is connected to the high-pressure / pulse pump via a low-pressure hose. The high-pressure / pulse pump is connected to the water pump outlet valve via a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant hose is equipped with a gas-liquid mixing connector, a main pressure sensor, a main flow sensor, a high-pressure sand injection system, a main pressure relief valve, and a tee. The high-pressure sand injection system consists of a tee on the high-pressure corrosion-resistant hose. One tee connects to the multiphase flow mixing chamber, and the other connects to the sand pressure balancing valve 12-1. The sand balancing valve is connected sequentially via the high-pressure corrosion-resistant hose to the sand pressure sensor 12-2, the sand flow sensor 12-3, the high-pressure corrosion-resistant sand tank 12-4, and the sand adding valve 12-5. The sand adding valve is connected to the multiphase flow mixing chamber via the high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant sand tank has a sand adding port. High-pressure corrosion-resistant hoses are connected to high-pressure corrosion-resistant tubing strings via high-pressure corrosion-resistant connectors. These tubing strings are then sequentially connected to a near-hole high-pressure corrosion-resistant sealing device, a high-pressure corrosion-resistant fracturing tubing string, a near-hole bottom high-pressure corrosion-resistant sealing device, and a high-strength corrosion-resistant drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock face. All relevant equipment is then connected to the pump monitoring system and the main monitoring system via corresponding monitoring lines. The two systems are then connected via a monitoring line from the pump monitoring system to the main system.

[0165] SF3, high-pressure liquid injection. After the equipment and pipeline connections are completed, close the main pressure relief valve 13, sand circuit pressure balancing valve 12-1, sand adding valve 12-5, and acid gas circuit pump outlet valve 3 through the main monitoring system, and open the water circuit pump outlet valve 7. Monitor the water level in the water tank. If the water level is less than 50%, add water to the water tank 5 by controlling the water replenishment valve 4 until the water tank capacity reaches 90%. Monitor and adjust the water level in the tank throughout the high-pressure water injection process. Before injection, observe the sand level in the high-pressure anti-corrosion sand tank through the main monitoring system. When the sand level is less than 50%, open the sand adding valve 12-7 through the monitoring system until the sand level in the sand tank exceeds 90%, then close the sand adding valve 12-7. Next, the high-pressure / pulse pump 6 is started via the main monitoring system 28. High-pressure water enters the high-pressure anti-corrosion hose and passes sequentially through the gas-liquid mixing connector 8, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the near-hole high-pressure anti-corrosion sealer 16, the high-pressure anti-corrosion fracturing tubing string 18, and the near-bottom high-pressure anti-corrosion sealer 17. When the water pressure does not exceed the pressure (5 MPa) at the multiphase fluid outlet 18-1 of the fracturing rod, the capsules of the near-hole high-pressure anti-corrosion sealer 16 and the near-bottom high-pressure anti-corrosion sealer 17 are opened and adhere to the rock wall 20, forming a fracturing sealed space. When the water pressure exceeds 5 MPa... After MPa, the multiphase fluid outlet valve of the fracturing rod opens, and high-pressure water enters the fracturing confined space. The water pressure acts on the rock wall, and when the rock reaches the critical fracturing pressure, the rock fractures, forming hydraulic fractures.

[0166] SF4 is pumped to inject a solid-liquid two-phase mixture. High-pressure fluid is pumped for a period of time (5-10 minutes) to reduce the pipeline pressure to 6-8 MPa. Then, the sand pressure balancing valve 12-1 is opened, and the opening of the sand-adding valve 12-5 is slowly adjusted through the main monitoring system. The injection sand ratio is calculated based on the reduction in sand volume. Solid particles and high-pressure liquid mix in the multiphase flow mixing chamber to form a solid-liquid two-phase fluid. The solid-liquid two-phase flow passes through the high-pressure anti-corrosion hose 9, high-pressure anti-corrosion connector 14, high-pressure anti-corrosion tubing string 15, near-hole high-pressure anti-corrosion sealing device 16, high-pressure anti-corrosion fracturing tubing string 18, and near-hole bottom high-pressure anti-corrosion sealing device 17. While passing through the high-pressure anti-corrosion fracturing tubing string, it enters the fracturing sealed space through the fracturing rod multiphase flow outlet, and then enters the liquid fracturing fracture, further expanding the fracture to form a dense fracture network, supporting the fracture, reducing fracture aperture changes, and maintaining the high conductivity of the fracture.

[0167] After the interaction of SF5 and solid-liquid two-phase flow with the rock is completed, the sand injection valve 12-5 is slowly closed by the main monitoring system 28. After the sand injection valve is closed for 3 minutes, the high pressure / pulse pump 6 is closed by the main monitoring system 28, and then the pressure relief valve is opened until the pressure in the pipeline is less than 0.25 MPa, and the fracturing is completed.

[0168] SF6. Move the pipeline to the next fracturing borehole and repeat SF1-SF5 to complete the regional intelligent fracturing operation.

[0169] The entire process of rock fracturing using solid-liquid two-phase fluid is controlled by a central monitoring system through the monitoring lines of each device. The array-type acoustic monitoring system 20-1 monitors and inverts the crack propagation morphology in real time, providing a basis for the formation of dense cracks. The system also adjusts the parameters of each system through an intelligent system to make the cracks propagate along the required path.

[0170] (4) Intelligent pumping of solid-gas two-phase mixing

[0171] The equipment involved mainly includes: high-pressure fluid storage system, high-pressure plunger pump for acid gas fluid, outlet valve of acid gas circuit pump, tee, high-pressure anti-corrosion hose, main pressure sensor, main flow sensor, high-pressure sand injection system, main pressure relief valve, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, high-pressure anti-corrosion sealing device near the borehole orifice, high-pressure anti-corrosion sealing device near the bottom of the borehole, high-pressure anti-corrosion fracturing tubing string, anti-corrosion high-strength drill bit, rock wall, array-type acoustic monitoring system, multiphase fluid absorber, pumping monitoring system, main monitoring system, and corresponding monitoring lines, etc.

[0172] Includes the following steps:

[0173] SG1. Drilling. Drilling holes (diameter, angle, length, etc.) into the rock face using a directional drilling rig.

[0174] SG2. Equipment and Piping Connections. Supercritical CO2 storage tank 1-1, liquid nitrogen storage tank 1-2, and other acidic or neutral fluid storage tanks 1-3 are connected in parallel. Supercritical CO2 storage tank 1-1 is connected to CO2 outlet valve 1-4 via high-pressure corrosion-resistant hose. Liquid nitrogen storage tank 1-2 is connected to liquid nitrogen outlet valve 1-5 via high-pressure corrosion-resistant hose. Other acidic or neutral fluid storage tanks 1-3 are connected to other fluid outlet valves 1-6 via high-pressure corrosion-resistant hose. Multiple lines are connected in parallel via a four-way valve. The acid gas path main outlet valve 1-10, acid gas path pressure sensor 1-11, and acid gas path flow sensor 1-12 are sequentially connected via high-pressure corrosion-resistant hose to form a high-pressure fluid storage system. The high-pressure fluid storage system is connected to an acid gas fluid high-pressure plunger pump via low-pressure corrosion-resistant hose. The acid gas fluid high-pressure plunger pump is connected to a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant hose is equipped with a gas-liquid mixing connector, a main pressure sensor, a main flow sensor, a high-pressure sand injection system, a main pressure relief valve, and a three-way valve. The high-pressure sand injection system consists of a tee connected to a high-pressure corrosion-resistant hose. One tee connects to a multiphase flow mixing chamber, and the other connects to a sand pressure balancing valve 12-1. The sand balancing valve is connected sequentially via the high-pressure corrosion-resistant hose to a sand pressure sensor 12-2, a sand flow sensor 12-3, a high-pressure corrosion-resistant sand tank 12-4, and a sand adding valve 12-5. The sand adding valve is connected to the multiphase flow mixing chamber via the high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant sand tank has a sand adding port. The high-pressure corrosion-resistant hose is connected to a high-pressure corrosion-resistant tubing string via a high-pressure corrosion-resistant connector. The high-pressure corrosion-resistant tubing string is sequentially connected to a near-hole high-pressure corrosion-resistant sealing device, a high-pressure corrosion-resistant fracturing tubing string, a near-hole bottom high-pressure corrosion-resistant sealing device, and a corrosion-resistant high-strength drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock face. All relevant equipment is then connected to the pump injection monitoring system and the main monitoring system via corresponding monitoring lines. The two systems are then connected via a monitoring line from the pump injection monitoring system to the main system.

[0175] SG3. Pumping high-pressure acid gas fluid. After the equipment and pipeline connections are completed, close the main pressure relief valve 13, sand pressure balance valve 12-1, sand adding valve 12-5, and water pump outlet valve 3 through the main monitoring system. Open the acid gas pump outlet valve 7 and the acid gas main outlet valve 1-10. Monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, a spare acid gas storage tank should be prepared. In addition, before pumping, observe the sand storage in the high-pressure anti-corrosion sand tank through the main monitoring system. When the sand storage is less than 50%, control the sand adding valve 12-7 to open through the monitoring system until the sand volume in the sand tank exceeds 90%, then close the sand adding valve 12-7. Next, control the opening of one of the following acid gas outlet valves through the main monitoring system 28: supercritical CO2 outlet valve 1-4, liquid nitrogen outlet valve 1-5, or other fluid outlet valve 1-6. The other two should be closed. The high-pressure plunger pump 2 for acid gas fluid is started by the overall monitoring system 28. High-pressure acid fluid or neutral gas enters the high-pressure anti-corrosion hose 9 and passes sequentially through the gas-liquid mixing connector 8, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the high-pressure anti-corrosion sealer near the wellhead 16, the high-pressure anti-corrosion fracturing tubing string 18, and the high-pressure anti-corrosion sealer near the bottom of the well. When the acid gas fluid pressure exceeds 5MPa after passing through the high-pressure anti-corrosion sealer near the wellhead 16 and the high-pressure anti-corrosion sealer near the bottom of the well, the multiphase fluid outlet valve of the fracturing rod opens, and the acid or neutral fluid enters the fracturing sealed space. The acid and neutral fluids act on the rock wall, softening the rock wall and causing the cracks to expand again, forming a dense fracture network structure.

[0176] SG4. Pumping the solid-liquid two-phase mixture. Pump the acid gas fluid for a period of time (3-5 minutes) to reduce the pipeline pressure to 6-8 MPa. Then, open the sand pressure balancing valve 12-1 and slowly adjust the opening of the sand addition valve 12-5 through the main monitoring system, calculating the injection sand ratio based on the sand reduction. Solid particles mix with the high-pressure acid gas fluid in the multiphase flow mixing chamber, forming a solid-gas two-phase fluid. The solid-gas two-phase flow passes through the high-pressure anti-corrosion hose 9, high-pressure anti-corrosion connector 14, high-pressure anti-corrosion tubing string 15, near-hole high-pressure anti-corrosion sealing device 16, high-pressure anti-corrosion fracturing tubing string 18, and near-hole bottom high-pressure anti-corrosion sealing device 17. While passing through the high-pressure anti-corrosion fracturing tubing string, it enters the fracturing sealed space through the fracturing rod multiphase flow outlet, and then enters the acid gas fluid fracturing fracture, further expanding the fracture to form a dense fracture network, supporting the fracture, reducing fracture aperture changes, and maintaining the fracture's high conductivity.

[0177] After the interaction between SG5, solid and gas two-phase fluid and rock is completed, the sand pressure balance valve and sand addition valve are closed sequentially through the main monitoring system 28. After 3 minutes, the acid gas outlet valve and acid gas line main outlet valve 1-10 are closed sequentially through the main monitoring system 28. Then, the acid gas fluid high-pressure plunger pump 2 is turned off. After waiting for 3 minutes, the pressure relief valve 13 is slowly opened until the pressure in the pipeline is less than 0.25 MPa, and the fracturing is completed.

[0178] SG6. Move the pipeline to the next fracturing borehole and repeat SG1-SG5 to complete the regional intelligent fracturing operation.

[0179] The entire process of solid-gas two-phase fluid fracturing of rock is controlled by the central monitoring system through the monitoring lines of each device. The array-type acoustic wave monitoring system 20-1 monitors and inverts the crack propagation morphology in real time, providing a basis for the formation of dense cracks. The system also adjusts the parameters of each system through an intelligent system to make the cracks propagate along the required path.

[0180] (5) Intelligent pumping of solid-liquid-gas multiphase mixing

[0181] The equipment involved mainly includes: high-pressure fluid storage system, high-pressure plunger pump for acid gas fluid, outlet valve of acid gas circuit pump, water tank, high-pressure / pulse pump, outlet valve of water circuit pump, gas-liquid mixing connector, high-pressure anti-corrosion hose, main circuit pressure sensor, main circuit flow sensor, high-pressure sand injection system, main circuit pressure relief valve, high-pressure anti-corrosion connector, high-pressure anti-corrosion tubing string, high-pressure anti-corrosion sealing device near the borehole orifice, high-pressure anti-corrosion sealing device near the bottom of the borehole, high-pressure anti-corrosion fracturing tubing string, anti-corrosion high-strength drill bit, rock wall, array-type acoustic monitoring system, multiphase fluid absorber, pumping monitoring system, main monitoring system, and corresponding monitoring lines, etc.

[0182] Includes the following steps:

[0183] SFG1. Drilling. Drilling holes (diameter, angle, length, etc.) into the rock face using a directional drilling rig.

[0184] SFG2, Equipment and Piping Connections. Connect the supercritical CO2 storage tank 1-1, liquid nitrogen storage tank 1-2, and other acidic or neutral fluid storage tanks 1-3 in parallel. Supercritical CO2 storage tank 1-1 is connected to the CO2 outlet valve 1-4 via a high-pressure corrosion-resistant hose. Liquid nitrogen storage tank 1-2 is connected to the liquid nitrogen outlet valve 1-5 via a high-pressure corrosion-resistant hose. Other acidic or neutral fluid storage tanks 1-3 are connected to other fluid outlet valves 1-6 via high-pressure corrosion-resistant hoses. Connect these multiple lines in parallel using a four-way valve. Then, connect the acid gas main outlet valve 1-10, acid gas pressure sensor 1-11, and acid gas flow sensor 1-12 sequentially via high-pressure corrosion-resistant hoses to form a high-pressure fluid storage system. The high-pressure fluid storage system is connected to the acid gas high-pressure plunger pump via a low-pressure corrosion-resistant hose, and the acid gas high-pressure plunger pump is connected to the high-pressure corrosion-resistant hose. A water tank is connected to a high-pressure water pipe in the mine, and a water supply valve is installed on the pipe. The water tank is connected to a high-pressure / pulse pump via a low-pressure hose, and the high-pressure / pulse pump is connected to the water pump outlet valve via a high-pressure corrosion-resistant hose. The water pump outlet valve and the acid gas pump outlet valve are connected to the gas-liquid mixing connector 8 via high-pressure corrosion-resistant hoses, and then connected to high-pressure corrosion-resistant hoses. A main pressure sensor, a main flow sensor, a high-pressure sand injection system, and a main pressure relief valve are then installed on the high-pressure corrosion-resistant hoses. The high-pressure sand injection system consists of a tee on the high-pressure corrosion-resistant hose; one tee connects to the multiphase flow mixing chamber, and the other connects to the sand pressure balancing valve 12-1. The sand balancing valve is connected sequentially to the sand pressure sensor 12-2, the sand flow sensor 12-3, the high-pressure corrosion-resistant sand tank 12-4, and the sand adding valve 12-5 via high-pressure corrosion-resistant hoses. The sand adding valve is connected to the multiphase flow mixing chamber via a high-pressure corrosion-resistant hose. The high-pressure corrosion-resistant sand tank has a sand adding port. High-pressure corrosion-resistant hoses are connected to high-pressure corrosion-resistant tubing strings via high-pressure corrosion-resistant connectors. These tubing strings are then sequentially connected to a near-hole high-pressure corrosion-resistant sealing device, a high-pressure corrosion-resistant fracturing tubing string, a near-hole bottom high-pressure corrosion-resistant sealing device, and a high-strength corrosion-resistant drill bit. A multiphase fluid absorber is installed at the borehole opening. Simultaneously, an array-type acoustic monitoring system is installed on the rock face. All relevant equipment is then connected to the pump monitoring system and the main monitoring system via corresponding monitoring lines. The two systems are then connected via a monitoring line from the pump monitoring system to the main system.

[0185] SFG3, Pumping High-Pressure Acid Gas. After the equipment and pipeline connections are completed, close the main pressure relief valve 13, sand pressure balancing valve 12-1, and sand adding valve 12-5 through the main monitoring system. Open the acid gas pump outlet valve 7, acid gas main outlet valve 1-10, and water pump outlet valve 3. Monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, prepare a spare acid gas storage tank. Monitor the water volume in the water tank. If the water volume is less than 50%, add water to the water tank 5 through the water replenishment valve 4 until the water tank capacity reaches 90%. Monitor and adjust the water volume in the tank throughout the high-pressure water pumping process. In addition, before pumping, observe the sand storage in the high-pressure anti-corrosion sand tank through the main monitoring system. When the sand storage is less than 50%, open the sand adding valve 12-7 through the monitoring system until the sand volume in the sand tank exceeds 90%, then close the sand adding valve 12-7.

[0186] Next, the main monitoring system 28 controls the opening of one of the following acid gas outlet valves: supercritical CO2 outlet valve 1-4, liquid nitrogen outlet valve 1-5, or other fluid outlet valve 1-6, while the other two remain closed. The main monitoring system 28 also controls the start of the high-pressure plunger pump 2, allowing high-pressure acidic fluid or neutral gas to enter the high-pressure anti-corrosion hose 9. Simultaneously, the main monitoring system 28 controls the start of the high-pressure / pulse pump 6, allowing high-pressure water to enter the high-pressure anti-corrosion hose. The gas and liquid are mixed in the gas-liquid mixing connector 8. Then, the gas and liquid two-phase fluid enters the high-pressure anti-corrosion hose and passes sequentially through the tee 8-1, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the high-pressure anti-corrosion sealer near the wellhead 16, the high-pressure anti-corrosion fracturing tubing string 18, and the high-pressure anti-corrosion sealer near the bottom of the well. When the pressure of the gas and liquid two-phase fluid exceeds 5 MPa after passing through the high-pressure anti-corrosion sealer near the wellhead 16 and the high-pressure anti-corrosion sealer near the bottom of the well, the multiphase fluid outlet valve of the fracturing rod opens, and the gas and liquid two-phase fluid enters the fracturing sealed space. The gas and liquid two-phase fluid acts on the rock wall, softening the rock wall and causing the cracks to expand again, forming a dense fracture network structure.

[0187] SFG4, Pumping a Solid-Liquid-Gas Multiphase Mixture. After pumping the gas-liquid two-phase fluid for a period of time (3-5 minutes), reduce the pipeline pressure to 6-8 MPa, then open the sand pressure balancing valve 12-1. Slowly adjust the opening of the sand adding valve 12-5 through the main monitoring system, and calculate the injection sand ratio based on the sand reduction. Solid particles mix with the high-pressure gas-liquid two-phase fluid in the multiphase flow mixing chamber to form a solid-liquid-gas multiphase fluid. The solid-liquid-gas multiphase fluid passes through the high-pressure anti-corrosion hose 9, high-pressure anti-corrosion connector 14, high-pressure anti-corrosion tubing string 15, near-hole high-pressure anti-corrosion sealing device 16, high-pressure anti-corrosion fracturing tubing string 18, and near-hole bottom high-pressure anti-corrosion sealing device 17. When passing through the high-pressure anti-corrosion fracturing tubing string, it enters the fracturing sealed space through the fracturing rod multiphase flow outlet, and then enters the gas-liquid two-phase fluid fracturing fracture, further expanding the fracture, forming a dense fracture network, supporting the fracture, reducing fracture aperture changes, and maintaining the high conductivity of the fracture.

[0188] After the interaction of SFG5, solid-liquid-gas multiphase fluid and rock is completed, the sand pressure balance valve and sand addition valve are closed sequentially through the main monitoring system 28. After 3 minutes, the acid gas outlet valve and acid gas line main outlet valve 1-10 are closed sequentially through the main monitoring system 28. Then, the acid gas fluid high-pressure plunger pump 2 and high-pressure / pulse pump 6 are turned off. After waiting for 3 minutes, the pressure relief valve 13 is slowly opened until the pressure in the pipeline is less than 0.3 MPa, and the fracturing is completed.

[0189] SFG6: Move the pipeline to the next fracturing borehole and repeat SG1-SG5 to complete the regional intelligent fracturing operation.

[0190] The entire process of rock fracturing using solid-liquid-gas multiphase fluids is controlled by a central monitoring system that monitors and controls the operation of all equipment through the monitoring lines of each device. The array-type acoustic monitoring system 20-1 monitors and inverts the crack propagation morphology in real time, providing a basis for the formation of dense cracks. It also adjusts the parameters of each system through an intelligent system to make the cracks propagate along the required path.

[0191] (6) Intelligent regulation of rock fracture morphology

[0192] Intelligent control of rock fracture morphology primarily employs adjustments to the flow rate, pressure, and frequency of the solid, liquid, and gas phases to control fracture propagation. Methods include using an array-type acoustic monitoring system to monitor fracture propagation in real time and retrieving control parameters based on the monitoring data to achieve the desired fracture morphology.

[0193] 1) Unidirectional crack control to crack network expansion. When monitoring shows that the crack is expanding in a single direction, if only water is injected, the pulsation frequency of the water injection should be increased. Through the pulsating effect of the water flow, fatigue damage should be formed on the crack surface, thereby breaking the control of the ground stress and forming microcracks on the inner wall of the crack. After the microcracks are formed, observe the cracks to start expanding. When the amplitude of the expansion length change decreases, reduce the water injection frequency and increase the discharge rate. Use high discharge rate to impact the microcracks, causing the microcracks to expand and form a crack network. If the effect is still not good, the frequency can be adjusted multiple times to allow the crack network to fully develop.

[0194] 2) Crack network control for unidirectional crack propagation. When monitoring and inversion show that crack propagation has become a multidirectional crack network, such as by injecting only water, gradually reduce the fluid pressure and frequency. Observe that the crack direction gradually changes from multidirectional to unidirectional. By reducing the water pressure and flow rate range, the cracks are made to propagate only along the direction most likely to propagate. Then, adjust and maintain the crack propagation direction.

[0195] 3) Fracture Network Boundary Control Methods. ① If it is necessary to control fractures from intersecting, and only through seepage migration (e.g., in leaching mining of metal mines), when the distance between the fracture network and the previous fracture network is 1 m, reduce the fluid pressure and flow rate to stop the fractures from extending further. Increase the number of fractures within the existing fracture network only through low-volume, high-frequency pulsation. A small amount of solid can also be added to block micro-fractures, reduce fracture filtration efficiency, and improve the overall permeability of the area, thereby increasing production. ② When it is necessary to control fracture intersections and make the fracture network continuous (e.g., in conventional and unconventional oil and gas extraction), after the fracture network is continuous, the fluid pressure does not need to overcome the tensile strength of the rock, thus gradually decreasing, causing fracture expansion to slow down or even stop. At this time, there are fewer fractures at the fracture network boundary. In this case, it is necessary to increase the pulsation frequency and flow rate so that the fluid loss is less than the injection volume, thereby promoting the expansion of the fracture network at the boundary, improving the permeability of the two borehole sections, and thus improving the conductivity of the fracture network. If the crack network monitoring based on acoustic signals is still not ideal, the proportion of solids (sand) in the fluid can be increased. By blocking the microcrack channels with solids, fluid loss can be reduced and fluid resistance increased, thereby allowing the crack network to develop more fully.

[0196] 4) Initial weakening of the fracture network. In the early stage of fracture propagation, in order to make the fractures propagate evenly in multiple directions, acidic fluid can be injected into the fractures for a period of time to weaken the rock layer and reduce the rock layer strength. Through the phase change of the gas, a relatively dense fracture network is formed in the closed section. Then, high-volume fracturing combined with sand addition is used to achieve the goal of fully developing the fracture network.

[0197] (7) Multiphase separation and recovery system

[0198] The equipment involved mainly includes: multiphase fluid absorbers, multiphase fluid transport pipelines, multiphase fluid separators, mixed gas pipelines, gas liquefaction and separation systems, liquefied gas storage tanks, pump monitoring systems, main monitoring systems, acid gas fluid storage tanks, and corresponding monitoring lines, etc.

[0199] When acidic fluid is injected into a borehole, if the gas escapes from the borehole, it will increase the concentration of CO2, N2, and other gases around the borehole. This can cause breathing difficulties for personnel working in the area. Therefore, it is necessary to recover the gas flowing out or seeping from the borehole. For acidic gases, at the borehole opening, some gas is first absorbed by an acidic gas absorption plate. The remaining gas and solid-liquid multiphase fluid enter the multiphase fluid transport pipeline and reach the multiphase fluid separator. In the separator, solids settle at the bottom, followed by liquids, and then gases. A solid-liquid discharge valve is installed at the bottom of the multiphase fluid separator. When the main monitoring system detects that the liquid level in the separator reaches 70% of the total separator volume, the lower solid-liquid discharge valve is opened to discharge the solid-liquid fluid. When the liquid level reaches 10% of the total separator volume, the lower solid-liquid discharge valve is closed. A gas pipeline is connected to the top of the multiphase fluid separator to deliver the gas to the gas liquefaction and separation system. The gas liquefaction and separation system then separates the multiple components in the mixed gas, such as CO2, CH4, and N2. The liquefied gas or supercritical gas is then stored in the corresponding liquefied gas storage tank. Finally, the liquefied gas or supercritical gas is injected into the acid gas fluid storage tank for recycling.

[0200] (8) CCUS Intelligent Monitoring and Analysis

[0201] The equipment involved mainly includes: high-pressure fluid storage system, rock wall, multiphase fluid absorber, gas liquefaction separation system, liquefied gas storage tank, main monitoring system and corresponding monitoring lines, etc.

[0202] CCUS stands for Carbon Capture, Utilization, and Storage. It involves collecting CO2 emitted in large quantities from the air or other industrial sources, forming a supercritical CO2 fluid, and then injecting this fluid into the formation. The CO2 reacts with the rock formation, solidifying it and weakening the rock, increasing the density of the fracture network, thus facilitating the extraction of oil, gas, or metal mines. CO2 not fully absorbed at the formation wall is stored using multiphase fluid absorbers, gas liquefaction separation systems, and liquefied gas storage tanks. CH4 from the reservoir is also stored and collected, reducing carbon emissions, increasing carbon utilization, and contributing to mitigating the greenhouse effect.

[0203] During CCUS intelligent monitoring and analysis, the carbon content change (Q1, mainly CO2) in the high-pressure fluid storage system is monitored through the overall monitoring system; the absorption amount (Q2) of the multiphase fluid absorber is monitored through the absorber monitoring line; and the CO2 content (Q3) and other carbon contents (Q4) separated from the mixed gas are monitored through the gas liquefaction and separation system monitoring line. The carbon sequestration capacity, capture capacity, and utilization rate are calculated, with the carbon sequestration capacity being Q. C = Q1 - Q2 - Q3, carbon capture amount is Q B = Q2 + Q4, carbon utilization rate is Q L =1-(Q2+ Q3) / Q1.

[0204] Example 1

[0205] A CO2 pre-fracturing and permeability enhancement (CCUS) device for underground mines includes a high-pressure fluid storage system 1, a high-pressure plunger pump for acid gas fluid 2, an acid gas pump outlet valve 3, a water supply valve 4, a water tank 5, a high-pressure / pulse pump 6, a water pump outlet valve 7, a gas-liquid mixing connector 8, a tee 8-1, a high-pressure corrosion-resistant hose 9, a main pressure sensor 10, a main flow sensor 11, a high-pressure sand injection system 12, a main pressure relief valve 13, a high-pressure corrosion-resistant connector 14, a high-pressure corrosion-resistant tubing string 15, a high-pressure corrosion-resistant sealing device near the borehole opening 16, a high-pressure corrosion-resistant sealing device near the bottom of the borehole 17, a high-pressure corrosion-resistant fracturing tubing string 18, a corrosion-resistant high-strength drill bit 19, a rock wall 20, a multiphase fluid absorber 21, a multiphase fluid transport pipeline 22, a multiphase fluid separator 23, a mixed gas pipeline 24, a gas liquefaction separation system 25, a liquefied gas storage tank 26, a pumping monitoring system 27, and a main monitoring system 28.

[0206] The high-pressure fluid storage system 1 includes: a supercritical CO2 storage tank 1-1, a liquid nitrogen storage tank 1-2, other acidic or neutral fluid storage tanks (e.g., low-concentration hydrochloric acid, sulfuric acid, etc.) 1-3, a CO2 outlet valve 1-4, a liquid nitrogen outlet valve 1-5, other fluid outlet valves 1-6, a CO2 outlet valve monitoring line 1-7, a liquid nitrogen outlet valve monitoring line 1-8, other fluid outlet valve monitoring lines 1-9, a total acid gas outlet valve 1-10, an acid gas pressure sensor 1-11, an acid gas flow sensor 1-12, a total acid gas outlet valve monitoring line 1-13, an acid gas pressure sensor monitoring line 1-14, and an acid gas flow sensor monitoring line 1-15.

[0207] The acid gas high-pressure plunger pump 2 is connected to the pumping monitoring system 27 via acid gas high-pressure plunger pump monitoring line 2-1 to monitor the start and stop of the acid gas high-pressure plunger pump 2. The acid gas pump outlet valve 3 is connected to the pumping monitoring system 27 via acid gas pump outlet valve monitoring line 3-1 to monitor the on / off status of the acid gas pump outlet valve 3. The water supply valve 4 is connected to the pumping monitoring system 27 via water supply valve monitoring line 4-1 to monitor the opening degree of the water supply valve 4. The water tank 5 is connected to the pumping monitoring system 27 via water tank level monitoring line 5-1 to monitor changes in the water level in the water tank 4. The high-pressure / pulse pump 6 is connected to the pumping monitoring system 27 via high-pressure / pulse pump monitoring line 6-1 to monitor the start and stop of the high-pressure / pulse pump 6. The water pump outlet valve 7 is connected to the pumping monitoring system 27 via water pump outlet valve monitoring line 7-1 to monitor the on / off status of the water pump outlet valve 7.

[0208] The high-pressure sand injection system 12 includes a sand pressure balancing valve 12-1, a sand pressure sensor 12-2, a sand flow sensor 12-3, a high-pressure corrosion-resistant sand tank 12-4, a sand adding valve 12-5, a multiphase flow mixing chamber 12-6, a sand adding port 12-7, a sand pressure balancing valve monitoring line 12-8, a sand pressure sensor detection line 12-9, a sand flow sensor monitoring line 12-10, a sand adding valve monitoring line 12-11, a sand quantity monitoring line 12-12, and a sand adding port monitoring line 12-13. The sand pressure balancing valve 12-1 is connected to the main monitoring system 28 via the sand pressure balancing valve 12-8 monitoring line to monitor the on / off status of the sand pressure balancing valve 12-1. The sand pressure sensor 12-2 is connected to the main monitoring system 28 via the sand pressure sensor monitoring line 12-9 to monitor the sand pressure. The sand flow sensor 12-3 is connected to the main monitoring system 28 via sand flow sensor monitoring line 12-10 to monitor the sand flow rate. The sand filling valve 12-5 is connected to the main monitoring system 28 via sand filling valve monitoring line 12-11 to monitor the opening degree of the sand filling valve 12-5. The high-pressure corrosion-resistant sand tank 12-4 is connected to the main monitoring system 28 via sand quantity monitoring line 12-12 to monitor the sand quantity inside the sand tank 12-4. The sand filling port 12-7 is connected to the main monitoring system 28 via sand filling port monitoring line 12-13 to monitor the opening degree of the sand filling port 12-7.

[0209] The main pressure relief valve 13 is connected to the main monitoring system 28 via the main pressure relief valve monitoring line 13-1 to monitor the valve's on / off status. The high-pressure corrosion-resistant fracturing string 18 is equipped with a multiphase flow outlet 18-1 for the passage of a multiphase mixture of solid, liquid, and gaseous fluids. An array-type acoustic monitoring system 20-1 is installed inside the rock wall 20 and connected to the main monitoring system 27 via the array-type acoustic monitoring system monitoring line 20-2 to analyze the rock fracture status in real time. The multiphase fluid absorber 21 contains an acid gas absorption plate 21-1 to absorb acid gases such as CO2, and is connected to the main monitoring system 28 via the absorber monitoring line 27-2 to monitor information such as the flow rate of each phase of the multiphase fluid passing through the absorber. The gas liquefaction separation system 25 is connected to the main monitoring system 28 via the gas liquefaction separation system monitoring line 25-1 to monitor gas composition and flow rate. The liquefied gas storage device 26 is connected to the main monitoring system 28 via the liquefied gas storage device monitoring line 26-1 to monitor the remaining liquefied gas quantity.

[0210] The pumping monitoring system 27 mainly consists of three modules: the acid gas path monitoring system 27-1, the water path monitoring system 27-2, and the fault alarm system 27-3. The main monitoring system 28 can observe the status of the pumping monitoring system 27 and control its operation through the main system monitoring line 27-4.

[0211] The overall monitoring system 28 includes the overall acid gas path monitoring system 28-1, the overall water path monitoring system 28-2, the overall sand path monitoring system 28-3, the CCUS analysis system 28-4, the rock stratum fracture status monitoring system 28-5, the safety monitoring system 28-6, and the effect analysis system 28-7.

[0212] Example 2

[0213] A method for pre-fracturing and permeability enhancement with carbon dioxide injection and CCUS intelligent control in underground mines includes the following steps:

[0214] Step 1, Drilling. A directional drilling rig is used to drill holes of the required dimensions (diameter, angle, length, etc.) into the rock face at a depth of 20 mm.

[0215] Step 2, Equipment and Piping Connection. Connect the supercritical CO2 storage tank 1-1, liquid nitrogen storage tank 1-2, and other acidic or neutral fluid storage tanks 1-3 in parallel. Supercritical CO2 storage tank 1-1 is connected to the CO2 outlet valve 1-4 via a high-pressure corrosion-resistant hose. Liquid nitrogen storage tank 1-2 is connected to the liquid nitrogen outlet valve 1-5 via a high-pressure corrosion-resistant hose. Other acidic or neutral fluid storage tanks 1-3 are connected to other fluid outlet valves 1-6 via high-pressure corrosion-resistant hoses. Connect the multiple lines in parallel using a four-way valve. Then, connect the acid gas main outlet valve 1-10, acid gas pressure sensor 1-11, and acid gas flow sensor 1-12 sequentially via high-pressure corrosion-resistant hoses to form a high-pressure fluid storage system 1. The high-pressure fluid storage system is connected to the acid gas high-pressure plunger pump 2 via a low-pressure corrosion-resistant hose. The acid gas high-pressure plunger pump 2 is connected to a high-pressure corrosion-resistant hose 9. Connect water tank 5 to the high-pressure water pipe in the mine, and install a water supply valve 4 on the pipe. The water tank is connected to the high-pressure / pulse pump 6 via a low-pressure hose. The high-pressure / pulse pump 6 is connected to the water pump outlet valve 7 via a high-pressure anti-corrosion hose 9. The water pump outlet valve 7 and the acid gas pump outlet valve 3 are connected to the gas-liquid mixing connector 8 via the high-pressure anti-corrosion hose 9, and then connected to the high-pressure anti-corrosion hose 9. Then, install a main pressure sensor 10, a main flow sensor 11, a high-pressure sand injection system 12, and a main pressure relief valve 13 on the high-pressure anti-corrosion hose 9. The high-pressure sand injection system 12 has a tee 8-1 on the high-pressure corrosion-resistant hose 9. One tee connects to the multiphase flow mixing chamber 12-6, and the other connects to the sand flow pressure balancing valve 12-1. The sand flow balancing valve 12-1 is connected in sequence to the sand flow pressure sensor 12-2, the sand flow sensor 12-3, the high-pressure corrosion-resistant sand tank 12-4, and the sand filling valve 12-5 via the high-pressure corrosion-resistant hose 9. The sand filling valve 12-5 is connected to the multiphase flow mixing chamber 12-6 via the high-pressure corrosion-resistant hose 9. The high-pressure corrosion-resistant sand tank 12-4 is equipped with a sand filling port 12-7. The high-pressure corrosion-resistant hose 9 is connected to the high-pressure corrosion-resistant tubing string 15 via the high-pressure corrosion-resistant connector 14. The high-pressure corrosion-resistant tubing string 15 is connected in sequence to the near-hole high-pressure corrosion-resistant sealing device 16, the high-pressure corrosion-resistant fracturing tubing string 18, the near-hole bottom high-pressure corrosion-resistant sealing device 17, and the corrosion-resistant high-strength drill bit 19. A multiphase fluid absorber 21 is installed at the borehole opening. At the same time, an array-type acoustic monitoring system 20-1 is installed on the rock wall, and then all relevant equipment is connected to the pumping monitoring system 27 and the main monitoring system 28 through corresponding monitoring or monitoring lines, and the two systems are connected to the main system monitoring line 27-4 through the pumping monitoring system.

[0216] Step 3: Pumping high-pressure liquid. After the equipment and pipeline connections are completed, monitor the fluid volume in the acid gas storage tank. If it is less than 50% of the storage tank capacity, a spare acid gas storage tank must be prepared. Monitor the water volume in the water tank. If the water volume is less than 50%, add water to the water tank 5 by controlling the water supply valve 4 until the water tank capacity reaches 90%. Monitor and adjust the water volume in the tank throughout the high-pressure water pumping process. In addition, before pumping, observe the sand storage in the high-pressure anti-corrosion sand tank through the main monitoring system. When the sand storage is less than 50%, control the sand adding valve 12-7 to open through the monitoring system until the sand volume in the sand tank exceeds 90%, then close the sand adding valve 12-7. The above solid-liquid-gas content is monitored through the main monitoring system 28 throughout the process. Close the main line pressure relief valve 13, sand line pressure balance valve 12-1, sand adding valve 12-5, and acid gas line pump outlet valve 3 through the main monitoring system 28, and open the water line pump outlet valve 7. Next, the high-pressure / pulse pump 6 is started via the main monitoring system 28. High-pressure water enters the high-pressure anti-corrosion hose and passes sequentially through the gas-liquid mixing connector 8, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the near-hole high-pressure anti-corrosion sealer 16, the high-pressure anti-corrosion fracturing tubing string 18, and the near-bottom high-pressure anti-corrosion sealer 17. When the water pressure does not exceed the pressure (5 MPa) at the multiphase fluid outlet 18-1 of the fracturing rod, the capsules of the near-hole high-pressure anti-corrosion sealer 16 and the near-bottom high-pressure anti-corrosion sealer 17 are opened and adhere to the rock wall 20, forming a fracturing sealed space. When the water pressure exceeds 5 MPa... After MPa, the multiphase fluid outlet valve of the fracturing rod opens, and high-pressure water enters the fracturing confined space. The water pressure acts on the rock wall, and when the rock reaches the critical fracturing pressure, the rock fractures, forming hydraulic fractures.

[0217] Step 4: Pump in high-pressure acid gas fluid to weaken the water pressure fracturing. After high-pressure water fracturing for 5-10 minutes, reduce the water pressure to 6-8 MPa. Then, through the main monitoring system 28, close the main pressure relief valve 13, sand pressure balancing valve 12-1, and sand adding valve 12-5, and open the acid gas pump outlet valve 7, the acid gas main outlet valve 1-10, and the water pump outlet valve 3. Next, through the main monitoring system 28, control the opening of the supercritical CO2 outlet valve 1-4 and close the liquid nitrogen outlet valve 1-5 or other fluid outlet valves 1-6. Through the main monitoring system 28, control the start of the high-pressure plunger pump 2 for acid gas fluid, allowing high-pressure acid fluid or neutral gas to enter the high-pressure anti-corrosion hose 9. Simultaneously, through the main monitoring system 28, control the start of the high-pressure / pulse pump 6, allowing high-pressure water to enter the high-pressure anti-corrosion hose. The gas and liquid are mixed in the gas-liquid mixing connector 8. Then, the gas and liquid two-phase fluid enters the high-pressure anti-corrosion hose and passes sequentially through the tee 8-1, the main pressure sensor 10, the main flow sensor 11, the multiphase flow mixing chamber 12-6, the high-pressure anti-corrosion connector 14, the high-pressure anti-corrosion tubing string 15, the high-pressure anti-corrosion sealer near the wellhead 16, the high-pressure anti-corrosion fracturing tubing string 18, and the high-pressure anti-corrosion sealer near the bottom of the well. When passing through the high-pressure anti-corrosion sealer near the wellhead 16 and the high-pressure anti-corrosion sealer near the bottom of the well, the gas and liquid two-phase fluid enters the fracturing sealed space. The gas and liquid two-phase fluid acts on the rock wall 20, softening the rock wall and causing the cracks to expand again, forming a weakened structure of the wall fracture network.

[0218] Step 5: Pumping the solid-liquid-gas multiphase mixture. After pumping the gas-liquid two-phase fluid for a period of time (5-10 min), reduce the pipeline pressure to 6-8 MPa, then open the sand pressure balancing valve 12-1. Slowly adjust the opening of the sand adding valve 12-5 through the overall monitoring system, and calculate the injection sand ratio based on the sand reduction. Solid particles and the high-pressure gas-liquid two-phase fluid mix in the multiphase flow mixing chamber to form a solid-liquid-gas multiphase fluid. The solid-liquid-gas multiphase fluid passes through the high-pressure anti-corrosion hose 9, high-pressure anti-corrosion connector 14, high-pressure anti-corrosion tubing string 15, near-hole high-pressure anti-corrosion sealing device 16, high-pressure anti-corrosion fracturing tubing string 18, and near-hole bottom high-pressure anti-corrosion sealing device 17. When passing through the high-pressure corrosion-resistant fracturing string 18, it enters the fracturing sealed space through the multiphase flow outlet 18-1 of the fracturing rod, and then enters the gas-liquid two-phase fluid fracturing fracture, which further expands the fracture, forms a dense fracture network, supports the fracture, reduces the change in fracture aperture, and maintains the high conductivity of the fracture.

[0219] Step 6: After the solid-liquid-gas multiphase fluid interacts with the rock, the sand pressure balancing valve and sand adding valve are closed sequentially through the main monitoring system 28. After 3 minutes, the acid gas outlet valve and the acid gas main outlet valve 1-10 are closed sequentially through the main monitoring system 28. Then, the acid gas fluid high-pressure plunger pump 2 and high-pressure / pulse pump 6 are turned off. After waiting for 3 minutes, the pressure relief valve 13 is slowly opened until the pressure in the pipeline is less than 0.3 MPa, and the fracturing is completed.

[0220] Step 7: Move the pipeline to the next fracturing borehole and repeat steps 1-6 to complete the regional intelligent fracturing operation.

[0221] The entire process of rock fracturing using solid-liquid-gas multiphase fluids is controlled by a central monitoring system that monitors and controls the operation of all equipment through the monitoring lines of each device. The array-type acoustic wave monitoring system 20-1 monitors and inverts the crack propagation morphology in real time, providing a basis for the formation of dense cracks, and adjusts the parameters of each system through an intelligent system to make the cracks propagate along the required path. The entire construction process is monitored and intelligently analyzed by CCUS data and feedback is provided.

Claims

1. A coal mine down carbon dioxide pre-fracturing sand injection anti-reflection, CCUS equipment, characterized in that, The application relates to a high-pressure pumping system for pumping fluid into a stratum, a high-pressure pumping system comprising a fluid high-pressure storage system and a pumping monitoring system; the fluid high-pressure storage system is used for storing supercritical CO2, liquid nitrogen and other acidic or neutral fluids, including a backup of supercritical CO2 gas; the pumping monitoring system is used for monitoring parameters of an acid gas path and a water path and an operating state of equipment, and performing equipment fault alarm; a high-pressure sand injection system is used for storing solid particles as a proppant, adjusting sand path pressure and flow, controlling sand injection amount, and mixing the proppant and the fluid in a multiphase flow mixing bin; an array type acoustic wave monitoring system is installed in a rock wall and is used for real-time analysis of a rock stratum fracture state; a gas liquefaction separation system is used for separating gas components in mixed gas delivered by a multiphase fluid separator, and liquefying the separated gas; and a total monitoring system is used for monitoring system parameters, controlling equipment operation, analyzing a rock stratum fracture state and a CCUS effect, and realizing whole-process management and control. The high-pressure pumping system further comprises an acid gas fluid high-pressure plunger pump, an acid gas path pump outlet valve, a water tank, a high-pressure / pulse pump, a water path pump outlet valve and a gas-liquid mixing connector; one end of the high-pressure / pulse pump is connected with the water tank, and the other end is connected with the water path pump outlet valve; one end of the acid gas fluid high-pressure plunger pump is connected with the fluid high-pressure storage system, and the other end is connected with the acid gas path pump outlet valve; the other end of the acid gas path pump outlet valve is connected with the gas-liquid mixing connector; the gas-liquid mixing connector is connected with the high-pressure sand injection system through a high-pressure corrosion-resistant rubber pipe; and the acid gas fluid high-pressure plunger pump, the high-pressure / pulse pump, the water path pump outlet valve, the acid gas path pump outlet valve and the pumping monitoring system are electrically connected. The application further comprises a liquefied gas storage device, a tee joint, a high-pressure corrosion-resistant connector, a high-pressure corrosion-resistant pipe column, a near-orifice high-pressure corrosion-resistant packer, a near-hole-bottom high-pressure corrosion-resistant packer, a high-pressure corrosion-resistant fracturing pipe column, a corrosion-resistant high-strength drill bit, a multiphase fluid absorber and a multiphase fluid separator; the corrosion-resistant high-strength drill bit, the high-pressure corrosion-resistant fracturing pipe column and the high-pressure corrosion-resistant pipe column are sequentially connected; the high-pressure corrosion-resistant connector is installed on the high-pressure corrosion-resistant pipe column; the high-pressure corrosion-resistant pipe column is connected with the high-pressure sand injection system; the near-hole-bottom high-pressure corrosion-resistant packer, the near-orifice high-pressure corrosion-resistant packer and the multiphase fluid absorber are sleeved and installed; the multiphase fluid absorber and the multiphase fluid separator are connected through a multiphase fluid transportation pipeline; the multiphase fluid separator is connected with the gas liquefaction separation system through a mixed gas pipeline; the liquefied gas storage device is connected between the fluid high-pressure storage system and the gas liquefaction separation system; one end of the tee joint is connected with the gas-liquid mixing connector, and the other end is connected with the high-pressure sand injection system; and the liquefied gas storage device and the multiphase fluid separator are electrically connected with the total monitoring system. ​ ​ ​ 2. The mine down carbon dioxide pre-frac frac sanding and CCUS equipment of claim 1, wherein, ​ 3. The mine under carbon dioxide pre-frac frac sanding out, CCUS equipment according to claim 2, characterized in that, ​ 4. The mine under carbon dioxide pre-frac frac sanding out, CCUS equipment of claim 3, characterized in that, The fluid high-pressure storage system comprises a supercritical CO2 storage tank, a liquid nitrogen storage tank, other acidic or neutral fluid storage tanks, a CO2 outlet valve, a liquid nitrogen outlet valve, other fluid outlet valves, a total acid gas path outlet valve, an acid gas path pressure sensor, and an acid gas path flow sensor; one end of the total acid gas path outlet valve is connected with the acid gas fluid high-pressure plunger pump, and the other end is connected with the supercritical CO2 storage tank, the liquid nitrogen storage tank, and the other acidic or neutral fluid storage tanks; the CO2 outlet valve is installed on the pipeline between the supercritical CO2 storage tank and the total acid gas path outlet valve; the liquid nitrogen outlet valve is installed on the pipeline between the liquid nitrogen storage tank and the total acid gas path outlet valve; the other fluid outlet valves are installed on the pipeline between the other acidic or neutral fluid storage tanks and the total acid gas path outlet valve; the acid gas path pressure sensor and the acid gas path flow sensor are installed on the pipeline between the total acid gas path outlet valve and the acid gas fluid high-pressure plunger pump support; the CO2 outlet valve, the liquid nitrogen outlet valve, the other fluid outlet valves, the total acid gas path outlet valve, the acid gas path pressure sensor, and the acid gas path flow sensor are electrically connected with the pump injection monitoring system.

5. The mine under carbon dioxide pre-pad frac pack, permeability, CCUS equipment of claim 3, wherein, The high-pressure sand injection system comprises a sand path pressure balance valve, a sand path pressure sensor, a sand path flow sensor, a high-pressure corrosion-resistant sand tank, a sand adding valve, and a multiphase flow mixing bin; the high-pressure corrosion-resistant sand tank is provided with a sand adding opening; the lower end of the high-pressure corrosion-resistant sand tank is connected with the multiphase flow mixing bin; the sand adding valve is installed on the pipeline between the high-pressure corrosion-resistant sand tank and the multiphase flow mixing bin; the multiphase flow mixing bin is connected between the high-pressure corrosion-resistant connector and the tee joint; one end of the sand path pressure balance valve is connected to the pipeline between the multiphase flow mixing bin and the tee joint, and the other end is connected to the upper end of the high-pressure corrosion-resistant sand tank; the sand path pressure sensor and the sand path flow sensor are connected to the pipeline between the sand path pressure balance valve and the high-pressure corrosion-resistant sand tank; the sand path pressure balance valve, the sand path pressure sensor, the sand path flow sensor, and the sand adding valve are electrically connected with the total monitoring system.

6. The mine under carbon dioxide pre-pad frac pack, permeability, CCUS equipment of claim 1, wherein, The pump injection monitoring system comprises an acid gas path monitoring system, a water path monitoring system, and a fault alarm system.

7. The mine under carbon dioxide pre-pad frac pack, permeability, CCUS equipment of claim 1, wherein, The total monitoring system comprises a total acid gas path monitoring system, a total water path monitoring system, a total sand path monitoring system, a CCUS analysis system, a rock fracture state monitoring system, a safety monitoring system, and an effect analysis system.

8. The mine under carbon dioxide pre-pad frac pack, permeability, CCUS equipment of claim 3, wherein, The water tank is provided with a water supplement valve; the water supplement valve is electrically connected with the pump injection monitoring system; the tee joint is provided with a total path pressure sensor; a total path flow sensor is installed on the pipeline between the tee joint and the high-pressure sand injection system; the total path pressure sensor and the total path flow sensor are electrically connected with the total monitoring system.

9. The mine under carbon dioxide pre-pad frac pack, permeability, CCUS equipment of claim 3, wherein, A total path pressure relief valve is installed on the pipeline between the high-pressure sand injection system and the high-pressure corrosion-resistant connector; the total path pressure relief valve is electrically connected with the total monitoring system.

10. The mine under carbon dioxide pre-pad frac pack, permeability, CCUS equipment of claim 3, wherein, The multiphase fluid absorber comprises an absorber pipe wall and an acid gas absorption plate; the acid gas absorption plate is installed in the absorber pipe wall; the acid gas absorption plate is provided with a circular hole for accommodating the high-pressure corrosion-resistant pipe column; the absorber pipe wall is provided with a solid-liquid overflow channel.

11. A coal mine down carbon dioxide pre-fracturing sanding permeability, CCUS intelligent control method, characterized by, The method comprises the following steps: Step 1: drilling construction is performed on the rock wall surface through a directional drilling machine; Step 2, connecting fluid high-pressure storage system, high-pressure pump injection system, high-pressure sand injection system, gas liquefaction separation system, array acoustic monitoring system, pump injection monitoring system, total monitoring system; Step 3, under the overall control of the monitoring system, pumping one or more fluids into the borehole, and simultaneously monitoring the rock fracture state in real time through the array acoustic monitoring system, and intelligently regulating the fracture propagation form; Step 4, absorbing and separating multi-phase fluids and recovering CO2 after fracturing; Step 5, at the same time, monitoring and analyzing the carbon storage amount, capture amount and utilization rate by the monitoring system, realizing the integrated operation of mine downhole fracturing and permeability improvement, carbon capture, utilization and storage.

12. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancement, CCUS intelligent control method, characterized in that, Step 3 adopts a high-pressure water intelligent pumping method, which specifically includes: F1, equipment and pipeline connection; connecting the water tank to the high-pressure water pipe under the mine, and setting a water supplement valve on the pipeline, connecting the water tank to the high-pressure / pulse pump through a low-pressure rubber pipe, connecting the high-pressure / pulse pump to the water pump outlet valve through a high-pressure corrosion-resistant rubber pipe, setting a gas-liquid mixing bin, a total road pressure sensor, a total road flow sensor, a total road pressure relief valve, a tee joint, and a multi-phase flow mixing bin on the high-pressure corrosion-resistant rubber pipe, connecting the high-pressure corrosion-resistant rubber pipe to the high-pressure corrosion-resistant pipe column through a high-pressure corrosion-resistant connector, and connecting the high-pressure corrosion-resistant pipe column to a near-hole high-pressure corrosion-resistant hole packer, a high-pressure corrosion-resistant fracturing pipe column, a near-hole bottom high-pressure corrosion-resistant hole packer, and a corrosion-resistant high-strength drill bit in sequence, and installing a multi-phase fluid absorber at the borehole opening; at the same time, installing an array acoustic monitoring system on the rock wall surface, and then connecting all related equipment to the pump injection monitoring system and the total monitoring system through corresponding monitoring or monitoring lines, and connecting the two systems through the pump injection monitoring system to the total system monitoring line; F2, pump high-pressure liquid; close the total road pressure relief valve, sand road pressure balance valve, sand adding valve, and acid gas road pump outlet valve through the total monitoring system, open the water pump outlet valve, monitor the water amount in the water tank, if the water amount is less than 50%, add water to the water tank through the control of the water supplement valve until the water amount reaches 90% of the water tank capacity, and monitor and adjust the water amount in the water tank during the whole high-pressure water pumping process; then start the high-pressure / pulse pump through the total monitoring system, high-pressure water enters the high-pressure corrosion-resistant rubber pipe, passes through the gas-liquid mixing bin, total road pressure sensor, total road flow sensor, multi-phase flow mixing bin, high-pressure corrosion-resistant connector, high-pressure corrosion-resistant pipe column, near-hole high-pressure corrosion-resistant hole packer, high-pressure corrosion-resistant fracturing pipe column, and near-hole bottom high-pressure corrosion-resistant hole packer in sequence; when passing through the near-hole high-pressure corrosion-resistant hole packer and the near-hole bottom high-pressure corrosion-resistant hole packer, the capsules of the near-hole high-pressure corrosion-resistant hole packer and the near-hole bottom high-pressure corrosion-resistant hole packer are opened and attached to the rock wall surface during the period when the water pressure does not exceed 5 MPa of the pressure of the multi-phase fluid outlet of the fracturing rod, forming a fracturing closed space; when the water pressure exceeds 5 MPa, the multi-phase fluid outlet valve of the fracturing rod is opened, high-pressure water enters the fracturing closed space, and the water pressure acts on the rock wall surface; when the rock reaches the critical fracture pressure, the rock breaks and forms a hydraulic fracture; F3, after the high-pressure water and rock interaction is completed, the high-pressure / pulse pump is closed through the total monitoring system, and then the pressure relief valve is opened until the pressure in the pipeline is less than 0.2 MPa, and the fracturing is completed. F4, move the pipeline to the next fracturing borehole, repeat F1 to F3, complete the regional intelligent control fracturing operation.

13. The method of claim 12, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, The whole process of the intelligent pump injection method of high-pressure liquid gas is controlled by the total monitoring system, the array acoustic monitoring system monitors and inverts the crack propagation form in real time, and adjusts the system parameters to make the crack expand along the required path.

14. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, Step 3 uses an intelligent pump injection method of high-pressure liquefied gas, which specifically includes: G1, equipment and pipeline connection; the supercritical CO2 storage tank, the liquid nitrogen storage tank, and the other acid or neutral fluid storage tank are connected in parallel, the supercritical CO2 storage tank is connected with the CO2 outlet valve through the high-pressure corrosion-resistant rubber pipe, the liquid nitrogen storage tank is connected with the liquid nitrogen outlet valve through the high-pressure corrosion-resistant rubber pipe, the other acid or neutral fluid storage tank is connected with the other fluid outlet valve through the high-pressure corrosion-resistant rubber pipe, the multiple parallel connections are connected through a four-way valve, and the acid gas road total outlet valve, the acid gas road pressure sensor, and the acid gas road flow sensor are connected in sequence through the high-pressure corrosion-resistant rubber pipe to form a high-pressure fluid storage system; the fluid high-pressure storage system is connected to the acid gas fluid high-pressure plunger pump through a low-pressure corrosion-resistant rubber pipe, the acid gas fluid high-pressure plunger pump is connected with the high-pressure corrosion-resistant rubber pipe, the high-pressure corrosion-resistant rubber pipe is provided with a gas-liquid mixing bin, a total road pressure sensor, a total road flow sensor, a total road pressure relief valve, and a multiphase flow mixing bin, the high-pressure corrosion-resistant rubber pipe is connected with the high-pressure corrosion-resistant pipe column through a high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column is sequentially connected with a near-hole high-pressure corrosion-resistant hole packer, a high-pressure corrosion-resistant fracturing pipe column, a near-hole bottom high-pressure corrosion-resistant hole packer, and a corrosion-resistant high-strength drill bit, and a multiphase fluid absorber is installed at the drill hole orifice; meanwhile, an array acoustic monitoring system is installed on the rock wall surface, and then all related equipment is connected to the pump injection monitoring system and the total monitoring system through corresponding monitoring or monitoring lines, and the two systems are connected through the pump injection monitoring system to the total system monitoring line; G2, pump injection of high-pressure acid gas fluid; the total road pressure relief valve, the sand road pressure balance valve, the sand adding valve, and the water road pump outlet valve are closed, and the acid gas road pump outlet valve and the acid gas road total outlet valve are opened through the total monitoring system; the amount of fluid in the acid gas storage tank is monitored, and if it is less than 50% of the storage tank capacity, a standby acid gas storage tank needs to be prepared; then, one of the supercritical CO2 outlet valve, the liquid nitrogen outlet valve, or the other fluid outlet valve is opened through the total monitoring system, and the other two are closed; the acid gas fluid high-pressure plunger pump is started through the total monitoring system, the high-pressure acid fluid or neutral gas enters the high-pressure corrosion-resistant rubber pipe, sequentially passes through the three-way valve, the total road pressure sensor, the total road flow sensor, the multiphase flow mixing bin, the high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column, the near-hole high-pressure corrosion-resistant hole packer, the high-pressure corrosion-resistant fracturing pipe column, and the near-hole bottom high-pressure corrosion-resistant hole packer, and when the acid gas fluid pressure exceeds 5 MPa after passing through the near-hole high-pressure corrosion-resistant hole packer and the near-hole bottom high-pressure corrosion-resistant hole packer, the fracturing rod multiphase fluid outlet valve is opened, the acid or neutral fluid enters the fracturing closed space, the acid and neutral fluids act on the rock wall surface to soften the rock wall surface, the crack expands again, and a dense crack network structure is formed; G3, after the acid gas fluid and rock interaction is completed, the acid gas outlet valve, the acid gas path total outlet valve are closed in turn through the total monitoring system, then the acid gas fluid high pressure plunger pump is closed, then after 3 min, the control pressure relief valve is slowly opened until the pipeline internal pressure is less than 0.15 MPa, the fracturing is completed; G4, the pipeline is moved to the next fracturing borehole, G1 to G3 are repeated, and the regional intelligent control fracturing operation is completed.

15. The method of claim 12, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, In the whole process of the high pressure liquefied gas intelligent pump injection method, all equipment operation is controlled by the total monitoring system, the array type acoustic wave monitoring system monitors and inverts the crack expansion form in real time, and each system parameter is adjusted, so that the crack expands along the required path.

16. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, The step 3 adopts a solid-liquid two-phase mixed intelligent pump injection method, and specifically includes: SF1, equipment and pipeline connection; the water tank is connected to the mine downhole high pressure water pipe, and a water replenishing valve is arranged on the pipeline; the water tank is connected to the high pressure / pulse pump through a low pressure rubber pipe; the high pressure / pulse pump is connected to the water path pump outlet valve through a high pressure corrosion resistant rubber pipe; a gas-liquid mixing bin, a total path pressure sensor, a total path flow sensor, a high pressure sand injection system, a total path pressure relief valve and a tee joint are arranged on the high pressure corrosion resistant rubber pipe; the high pressure sand injection system is that a tee joint is arranged on the high pressure corrosion resistant rubber pipe, one way is connected to the multiphase flow mixing bin, and the other way is connected to the sand path pressure balance valve; the sand path balance valve is connected to the sand path pressure sensor, the sand path flow sensor, the high pressure corrosion resistant sand tank and the sand adding valve in sequence through the high pressure corrosion resistant rubber pipe; the sand adding valve is connected to the multiphase flow mixing bin through the high pressure corrosion resistant rubber pipe; the high pressure corrosion resistant sand tank is provided with a sand adding port; the high pressure corrosion resistant rubber pipe is connected to the high pressure corrosion resistant pipe column through a high pressure corrosion resistant connector; the high pressure corrosion resistant pipe column is connected to the near-hole high pressure corrosion resistant hole packer, the high pressure corrosion resistant fracturing pipe column and the near-hole bottom high pressure corrosion resistant hole packer in sequence; the corrosion resistant high strength drill bit is arranged at the drill hole hole; the multiphase flow absorber is arranged at the rock wall surface; then all related equipment is connected to the pump injection monitoring system and the total monitoring system through corresponding monitoring or monitoring lines; and the two systems are connected through the pump injection monitoring system to the total system monitoring line. SF2, pump high-pressure liquid; through the total monitoring system, close the total road unloading pressure valve, sand road pressure balance valve, sand valve, acid gas road pump outlet valve, open water pump outlet valve, monitor the water quantity in the water tank, if the water quantity is less than 50%, add water to the water tank through the control of the water supplement valve until the water tank capacity reaches 90%, the high-pressure water pump injection process is monitored and the water quantity in the water tank is adjusted; before pumping, observe the sand storage in the high-pressure corrosion-resistant sand tank through the total monitoring system, when the sand storage is less than 50%, control the sand valve to open through the monitoring system until the sand quantity in the sand tank exceeds 90% and the sand valve is closed; then control the high-pressure / pulse pump to start through the total monitoring system, the high-pressure water enters the high-pressure corrosion-resistant hose, and then passes through the gas-liquid mixing bin, the total road pressure sensor, the total road flow sensor, the multiphase flow mixing bin, the high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column, the near-hole high-pressure corrosion-resistant packer, the high-pressure corrosion-resistant fracturing pipe column, and the near-hole bottom high-pressure corrosion-resistant packer; when passing through the near-hole high-pressure corrosion-resistant packer and the near-hole bottom high-pressure corrosion-resistant packer, the capsules of the near-hole high-pressure corrosion-resistant packer and the near-hole bottom high-pressure corrosion-resistant packer are opened and attached to the rock wall to form a fracturing closed space during the period when the water pressure does not exceed 5 MPa of the pressure of the multiphase fluid outlet of the fracturing rod; when the water pressure exceeds 5 MPa, the outlet valve of the multiphase fluid of the fracturing rod is opened, the high-pressure water enters the fracturing closed space, and the water pressure acts on the rock wall; when the rock reaches the critical fracture pressure, the rock breaks and forms a hydraulic fracture; SF3, pump solid-liquid two-phase mixed liquid; after pumping high-pressure fluid for a period of time, reduce the pipe pressure to 6-8 MPa, then open the sand road pressure balance valve, slowly adjust the opening degree of the sand valve through the total monitoring system, and calculate the injection sand ratio through the sand reduction amount; the solid particles and the high-pressure liquid are mixed in the multiphase flow mixing bin to form a solid-liquid two-phase fluid; the solid-liquid two-phase fluid passes through the high-pressure corrosion-resistant hose, the high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column, the near-hole high-pressure corrosion-resistant packer, the high-pressure corrosion-resistant fracturing pipe column, and the near-hole bottom high-pressure corrosion-resistant packer; when passing through the high-pressure corrosion-resistant fracturing pipe column, the multiphase flow outlet of the fracturing rod enters the fracturing closed space, and then enters the liquid fracturing fracture to further expand the fracture, form a dense fracture network, support the fracture, reduce the fracture opening degree change, and maintain the high conductivity of the fracture; SF4, after the solid-liquid two-phase flow acts on the rock, slowly close the sand valve through the total monitoring system, close the sand valve for 3 minutes, then control the high-pressure / pulse pump to close through the total monitoring system, and then control the pressure relief valve to open until the pressure in the pipe is less than 0.25 MPa, and the fracturing is completed; SF5, move the pipe to the next fracturing borehole, repeat SF1-SF4, and complete the regional intelligent fracturing operation.

17. The method of claim 16, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, The solid-liquid two-phase mixed intelligent pumping method is implemented throughout the process, and all equipment operations are controlled by the total monitoring system. The array acoustic monitoring system monitors and inverts the fracture expansion form in real time, adjusts the system parameters, and makes the fracture expand along the required path.

18. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, Step 3 adopts a solid-gas two-phase mixed intelligent pumping method, which specifically includes: SG1, device and pipeline connection; the supercritical CO2 storage tank, liquid nitrogen storage tank, other acid or neutral fluid storage tank are connected in parallel, the supercritical CO2 storage tank is connected with CO2 outlet valve through high-pressure corrosion-resistant rubber pipe, the liquid nitrogen storage tank is connected with liquid nitrogen outlet valve through high-pressure corrosion-resistant rubber pipe, the other acid or neutral fluid storage tank is connected with other fluid outlet valve through high-pressure corrosion-resistant rubber pipe, multiple parallel connection is formed through four-way, acid gas road total outlet valve, acid gas road pressure sensor, acid gas road flow sensor are connected in sequence through high-pressure corrosion-resistant rubber pipe, and high-pressure fluid storage system is formed;The fluid high-pressure storage system is connected to the acid gas fluid high-pressure plunger pump through low-pressure corrosion-resistant rubber pipe, the acid gas fluid high-pressure plunger pump is connected with high-pressure corrosion-resistant rubber pipe, gas-liquid mixing bin, total road pressure sensor, total road flow sensor, high-pressure sand injection system, total road pressure relief valve and three-way are arranged on the high-pressure corrosion-resistant rubber pipe;The high-pressure sand injection system is that three-way is arranged on the high-pressure corrosion-resistant rubber pipe, one way is connected with multiphase flow mixing bin, another way is connected with sand road pressure balance valve, sand road balance valve is connected with sand road pressure sensor, sand road flow sensor, high-pressure corrosion-resistant sand tank and sand valve in sequence through high-pressure corrosion-resistant rubber pipe, the sand valve is connected with multiphase flow mixing bin through high-pressure corrosion-resistant rubber pipe, and the high-pressure corrosion-resistant sand tank is provided with sand adding port;The high-pressure corrosion-resistant rubber pipe is connected with high-pressure corrosion-resistant pipe column through high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column is connected with near-orifice high-pressure corrosion-resistant hole packer, high-pressure corrosion-resistant fracturing pipe column, near-hole bottom high-pressure corrosion-resistant hole packer and corrosion-resistant high-strength drill bit in sequence, and multiphase fluid absorber is installed at the drilling hole orifice;Array type acoustic monitoring system is installed on the rock wall surface at the same time, then all related devices are connected to pump injection monitoring system and total monitoring system through corresponding monitoring or monitoring line, and the two systems are connected through pump injection monitoring system to total system monitoring line; SG2, pump high-pressure acid gas fluid; through the total monitoring system, close the total road pressure relief valve, sand road pressure balance valve, sand valve, water road pump outlet valve, open acid gas road pump outlet valve, acid gas road total outlet valve; monitor the fluid volume in the acid gas storage tank, if less than 50% of the storage tank capacity, need to prepare a standby acid gas storage tank; in addition, before pumping, through the total monitoring system to observe the sand storage in the high-pressure corrosion-resistant sand tank, when the sand storage is less than 50%, through the monitoring system to control the sand valve to open, until the sand in the sand tank is more than 90%, close the sand valve; then, through the total monitoring system to control the opening of the supercritical CO2 outlet valve, the liquid nitrogen outlet valve, or the acid gas outlet valve of the other fluid outlet valve, the other two are in the closed state; through the total monitoring system to control the acid gas fluid high-pressure plunger pump to start, the high-pressure acid fluid or neutral gas enters the high-pressure corrosion-resistant hose, in turn through the gas-liquid mixing bin, the total road pressure sensor, the total road flow sensor, the multiphase flow mixing bin, the high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column, the near-hole high-pressure corrosion-resistant packer, the high-pressure corrosion-resistant fracturing pipe column, the near-hole bottom high-pressure corrosion-resistant packer, when the acid gas fluid pressure exceeds 5 MPa after passing through the near-hole high-pressure corrosion-resistant packer and the near-hole bottom high-pressure corrosion-resistant packer, the fracturing rod multiphase fluid outlet valve opens, the acid or neutral fluid enters the fracturing closed space, the acid and neutral fluid act on the rock wall, making the rock wall soften, the crack expands again, forming a dense fracture network structure; SG3, pump solid-liquid two-phase mixed liquid; pump acid gas fluid for a period of time, reduce the pipeline pressure to 6~8 MPa, then open the sand road pressure balance valve, slowly adjust the sand valve opening degree through the total monitoring system, calculate the sand injection ratio by the amount of sand reduction; solid particles and high-pressure acid gas fluid are mixed in the multiphase flow mixing bin to form solid-gas two-phase fluid; solid-gas two-phase fluid passes through high-pressure corrosion-resistant hose, high-pressure corrosion-resistant connector, high-pressure corrosion-resistant pipe column, near-hole high-pressure corrosion-resistant packer, high-pressure corrosion-resistant fracturing pipe column, near-hole bottom high-pressure corrosion-resistant packer; when passing through the high-pressure corrosion-resistant fracturing pipe column, enter the fracturing closed space through the fracturing rod multiphase flow outlet, then enter the acid gas fluid fracturing crack, expand the crack again, form a dense fracture network, and support the crack, reduce the crack opening degree change, maintain high conductivity of the crack; SG4, after the solid-gas two-phase fluid acts on the rock, close the sand road pressure balance valve and the sand valve through the total monitoring system, then close the acid gas outlet valve, the acid gas road total outlet valve, and the acid gas fluid high-pressure plunger pump through the total monitoring system, then control the pressure relief valve to open slowly after 3 min, until the pressure in the pipeline is less than 0.25 MPa, the fracturing is completed; SG5, move the pipeline to the next fracturing borehole, repeat SG1 to SG4, complete the regional intelligent control fracturing operation.

19. The method of claim 18, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, The solid-gas two-phase mixed intelligent pumping method implements the whole process, all equipment is controlled by the total monitoring system, the array acoustic monitoring system monitors and inverts the crack expansion form in real time, adjusts the system parameters, and makes the crack expand along the required path.

20. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, Step 3 uses a solid-liquid-gas multiphase mixing intelligent pump injection method, specifically comprising: SFG1, equipment and pipeline connection; the supercritical CO2 storage tank, liquid nitrogen storage tank, other acid or neutral fluid storage tank are connected in parallel, the supercritical CO2 storage tank is connected with the CO2 outlet valve through the high-pressure corrosion-resistant rubber pipe, the liquid nitrogen storage tank is connected with the liquid nitrogen outlet valve through the high-pressure corrosion-resistant rubber pipe, the other acid or neutral fluid storage tank is connected with the other fluid outlet valve through the high-pressure corrosion-resistant rubber pipe, the multiple parallel connections are connected through a four-way valve, the acid gas road total outlet valve, the acid gas road pressure sensor, the acid gas road flow sensor are connected in sequence through the high-pressure corrosion-resistant rubber pipe, and a high-pressure fluid storage system is formed; the fluid high-pressure storage system is connected to the acid gas fluid high-pressure plunger pump through the low-pressure corrosion-resistant rubber pipe, and the acid gas fluid high-pressure plunger pump is connected with the high-pressure corrosion-resistant rubber pipe; the water tank is connected to the mine high-pressure water pipe, and a water supplement valve is arranged on the pipeline, the water tank is connected to the high-pressure / pulse pump through the low-pressure rubber pipe, and the high-pressure / pulse pump is connected with the water road pump outlet valve through the high-pressure corrosion-resistant rubber pipe; the water road pump outlet valve and the acid gas road pump outlet valve are connected to the gas-liquid mixing bin through the high-pressure corrosion-resistant rubber pipe, and then the high-pressure corrosion-resistant rubber pipe is connected; then a total road pressure sensor, a total road flow sensor, a high-pressure sand injection system and a total road pressure relief valve are arranged on the high-pressure corrosion-resistant rubber pipe; the high-pressure sand injection system is provided with a three-way valve on the high-pressure corrosion-resistant rubber pipe, one way is connected with the multiphase flow mixing bin, and the other way is connected with the sand road pressure balance valve; the sand road balance valve is connected with the sand road pressure sensor, the sand road flow sensor, the high-pressure corrosion-resistant sand tank and the sand adding valve in sequence through the high-pressure corrosion-resistant rubber pipe, the sand adding valve is connected with the multiphase flow mixing bin through the high-pressure corrosion-resistant rubber pipe, and the high-pressure corrosion-resistant sand tank is provided with a sand adding port; the high-pressure corrosion-resistant rubber pipe is connected with the high-pressure corrosion-resistant pipe column through the high-pressure corrosion-resistant connector, and the high-pressure corrosion-resistant pipe column is sequentially connected with the near-hole high-pressure corrosion-resistant hole packer, the high-pressure corrosion-resistant fracturing pipe column, the near-hole bottom high-pressure corrosion-resistant hole packer and the corrosion-resistant high-strength drill bit; a multiphase fluid absorber is installed at the drilling hole; at the same time, an array type acoustic wave monitoring system is installed on the rock wall surface, and then all related equipment is connected to the pump injection monitoring system and the total monitoring system through corresponding monitoring or monitoring lines, and the two systems are connected through the pump injection monitoring system to the total system monitoring line; SFG2, pump injection of high-pressure acid gas fluid; the total road pressure relief valve, the sand road pressure balance valve and the sand adding valve are closed, the acid gas road pump outlet valve, the acid gas road total outlet valve and the water road pump outlet valve are opened through the total monitoring system, the fluid amount in the acid gas storage tank is monitored, if it is less than 50% of the storage tank capacity, a standby acid gas storage tank needs to be prepared; the water amount in the water tank is monitored, if the water amount is less than 50%, water is added to the water tank through the control of the water supplement valve until the water amount reaches 90% of the water tank capacity, the water amount in the water tank is monitored and adjusted during the whole high-pressure water pump injection process; in addition, before pump injection, the sand storage amount in the high-pressure corrosion-resistant sand tank is observed through the total monitoring system, when the sand storage amount is less than 50%, the sand adding valve is opened through the monitoring system until the sand amount in the sand tank exceeds 90%, and then the sand adding valve is closed. Then, one of the supercritical CO2 outlet valve, liquid nitrogen outlet valve, or other fluid outlet valve is opened by the total monitoring system control, and the other two are in the closed state; the acid gas fluid high-pressure plunger pump is started by the total monitoring system control, and the high-pressure acid fluid or neutral gas enters the high-pressure corrosion-resistant rubber pipe; at the same time, the high-pressure / pulse pump is started by the total monitoring system control, and the high-pressure water enters the high-pressure corrosion-resistant rubber pipe; the gas-liquid two-way completes mixing in the gas-liquid mixing bin, and then the gas-liquid two-phase fluid enters the high-pressure corrosion-resistant rubber pipe, and then passes through the three-way valve, the total road pressure sensor, the total road flow sensor, the multiphase flow mixing bin, the high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column, the near-hole high-pressure corrosion-resistant hole packer, the high-pressure corrosion-resistant fracturing pipe column, and the near-hole bottom high-pressure corrosion-resistant hole packer. When passing through the near-hole high-pressure corrosion-resistant hole packer and the near-hole bottom high-pressure corrosion-resistant hole packer, when the gas-liquid two-phase fluid pressure exceeds 5 MPa, the fracturing rod multiphase fluid outlet valve is opened, and the gas-liquid two-phase fluid enters the fracturing closed space. The gas-liquid two-phase fluid acts on the rock wall surface, softens the rock wall surface, and expands the fracture again to form a dense fracture network structure. SFG3, pump solid-liquid-gas multiphase mixed liquid; after pumping the gas-liquid two-phase fluid for a period of time, the pipeline pressure is reduced to 6-8 MPa, then the sand road pressure balance valve is opened, the sand injection valve opening degree is slowly adjusted by the total monitoring system, and the sand injection ratio is calculated by the sand amount reduction; the solid particles and the high-pressure gas-liquid two-phase fluid are mixed in the multiphase flow mixing bin to form a solid-liquid-gas multiphase fluid; the solid-liquid-gas multiphase fluid passes through the high-pressure corrosion-resistant rubber pipe, the high-pressure corrosion-resistant connector, the high-pressure corrosion-resistant pipe column, the near-hole high-pressure corrosion-resistant hole packer, the high-pressure corrosion-resistant fracturing pipe column, and the near-hole bottom high-pressure corrosion-resistant hole packer; when passing through the high-pressure corrosion-resistant fracturing pipe column, the fracturing rod multiphase flow outlet enters the fracturing closed space, and then enters the gas-liquid two-phase fluid fracturing fracture to expand the fracture again, form a dense fracture network, support the fracture, reduce the fracture opening degree change, and maintain the high conductivity of the fracture; SFG4, after the solid-liquid-gas multiphase fluid acts on the rock, the sand road pressure balance valve and the sand injection valve are closed in sequence by the total monitoring system, and after 3 minutes, the acid gas outlet valve, the acid gas road total outlet valve, the acid gas fluid high-pressure plunger pump, and the high-pressure / pulse pump are closed in sequence, then after 3 minutes, the pressure relief valve is slowly opened, until the pressure in the pipeline is less than 0.3 MPa, and the fracturing is completed; SFG5, move the pipeline to the next fracturing borehole, repeat SG1 to SG4, and complete the regional intelligent control fracturing operation.

21. The method of claim 19, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, The solid-liquid-gas multiphase mixing intelligent pumping method implements the whole process, and all equipment is controlled by the total monitoring system. The array acoustic wave monitoring system monitors and inverts the fracture expansion morphology in real time, adjusts the system parameters, and expands the fracture along the required path.

22. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, In step 3, the method for intelligently controlling the fracture expansion morphology comprises: 1) Single crack regulation for crack network expansion; when the crack is observed to expand in a single direction by monitoring and inversion, if only water injection is used, the pulsation frequency of water injection is increased, the fatigue damage of the crack surface is formed by the pulsation of water flow, thereby breaking the control of the ground stress and forming micro-cracks on the inner wall of the crack. When the expansion length changes, the injection frequency is reduced and the displacement is increased. The micro-cracks are expanded by high displacement impact to form a crack network morphology. If the effect is still not good, the frequency can be adjusted several times to fully develop the crack network; 2) Crack network regulation for single crack expansion; when the crack is observed to expand in multiple directions by monitoring and inversion, if only water injection is used, the fluid pressure and frequency are gradually reduced, and the crack direction is gradually changed from multiple directions to one direction. By reducing the water pressure and flow range, the crack only expands in the most easily expandable direction, and then the crack expansion direction is adjusted and maintained; 3) Crack network boundary regulation method; ① If the crack must not intersect, only through seepage migration, when the crack network is 1m away from the previous fractured crack network, the fluid pressure and flow are reduced to stop the crack from extending to the far end. Small displacement and high frequency pulsation can be used to increase the crack in the existing crack network. A small amount of solid can also be added to block the micro-cracks, reduce the crack filtration efficiency, and improve the overall permeability of the region, thereby improving the yield; ② When the crack must intersect to make the crack network through, after the crack network is through, the fluid pressure does not need to overcome the rock tensile strength, so as to gradually decrease, so that the crack expands slowly or even stops. At this time, the number of cracks at the junction is small; At this time, the pulsation frequency is increased and the displacement is increased, so that the fluid loss is less than the injection amount, thereby promoting the expansion of the crack network at the junction and improving the permeability between the two boreholes, thereby improving the conductivity of the crack network; At this time, if the crack network effect is still not ideal according to the acoustic signal monitoring, the solid proportion in the fluid can be increased to block the micro-crack channel by the solid, reduce the fluid loss, and increase the fluid resistance, thereby making the crack network more fully developed; 4) Crack network initial weakening; in the early stage of crack expansion, in order to make the crack expand uniformly in multiple directions, acid gas fluid can be injected into the crack for a period of time to weaken the rock mass and reduce the strength of the rock mass. A relatively dense crack network is formed in the closed section by the phase change of the gas, and then large displacement fracturing is used combined with sand addition to achieve the purpose of full development of the crack network.

23. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, In step 5, the CCUS intelligent monitoring method is used to monitor and analyze the carbon sequestration, capture and utilization, which specifically includes: The carbon amount change Q1 of the fluid high-pressure storage system is monitored by the total monitoring system, the absorption amount Q2 of the multiphase fluid absorber is monitored by the absorber monitoring line, the CO2 content Q3 separated from the mixed gas and other carbon content Q4 are monitored by the gas liquefaction separation system monitoring line; the carbon storage amount, capture amount and utilization rate are calculated, the carbon storage amount is Q C = Q1- Q2- Q3, the carbon capture amount is Q B = Q2+ Q4, and the carbon utilization rate is Q L =1-(Q2+ Q3) / Q1.

24. The method of claim 11, wherein the method is a coal mine down pre-frac frac sanding and permeability enhancing, CCUS smart control method, characterized in that, When injecting acid gas fluid into a borehole, the gas flowing out or seeping out of the borehole is recovered, specifically including: for acid gas, first needs to be absorbed by acid gas absorption plate at the orifice, the rest of the gas and solid-liquid multiphase fluid enters the multiphase fluid conveying pipeline, reaches the multiphase fluid separator, and the solid-liquid-gas multiphase fluid is in the separator, the solid is deposited at the lowermost part, the liquid is next, and the gas is at the uppermost part; a solid-liquid discharge valve is arranged at the lower part of the multiphase fluid separator, when the total monitoring system monitors that the liquid level in the separator reaches 70% of the total amount of the separator, the lower solid-liquid discharge valve is opened, and the solid-liquid fluid is discharged, when the liquid level reaches 10% of the total amount of the separator, the lower solid-liquid discharge valve is closed; the gas pipeline is connected at the top of the multiphase fluid separator and sent to the gas liquefaction separation system, then the multi-component in the mixed gas is separated through the gas liquefaction separation system, then the liquefied gas or supercritical gas is respectively stored in the corresponding liquefied gas storage, and then the liquefied gas or supercritical gas is filled into the acid gas fluid storage tank for recycling.

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