Method for preventing water inrush and scouring in hard fault deep area fracturing
By constructing a fracturing and drainage network and a diversion borehole system in the deep region of hard faults, the problem of synergistic management of high stress and high water pressure in hard faults during deep mining was solved, enabling proactive prevention and control of water inrush and rock bursts, and reducing the cost of mine disaster prevention systems.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF MINING & TECH
- Filing Date
- 2026-04-21
- Publication Date
- 2026-06-19
AI Technical Summary
Existing technologies lack synergistic treatment methods that can simultaneously relieve high stress and high water pressure in hard faults during deep mining, resulting in poor anti-scouring effects and limitations of single drainage or pressure relief measures.
By implementing directional hydraulic fracturing in the deep region of hard faults, a fracturing drainage network is constructed and connected to the diversion borehole system to form a collaborative prevention and control system. This allows for real-time monitoring and optimization of drainage strategies to reduce water pressure and stress in the fault zone.
This has enabled a shift from passive disaster response to proactive source control, effectively preventing sudden water inrushes and rock bursts, significantly reducing the life-cycle cost of mine disaster prevention systems, and achieving a balance between safety and economic benefits.
Smart Images
Figure CN122236503A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of deep mining technology, and in particular to a method for fracturing, draining, controlling water flow, and preventing erosion in deep areas of hard faults. Background Technology
[0002] Hard faults (such as siliceous cemented faults) are a major source of complex hazards in deep mining. Their hazard mechanism has a typical duality: on the one hand, the fault zone has high strength and good integrity due to siliceous cementation, becoming a "high-stress energy storage body" that accumulates huge elastic energy under high ground stress environment, which can easily induce strong mine earthquakes and even rock bursts; on the other hand, its original fractures are not well developed, and it naturally appears as a "weakly water-conducting water-isolated body", but under the disturbance of mining stress, it is prone to brittle shear penetration, instantly forming a high-pressure water-conducting channel and triggering catastrophic water inrush.
[0003] Existing prevention and control technologies mostly adopt a "single-hazard management" approach, which has fundamental limitations: shallow drainage alone can only reduce water pressure locally and cannot relieve stress concentration in the deep part of the fault, so the anti-scour effect is minimal; while single local pressure relief blasting may disrupt the relative balance of the fault structure and instead exacerbate the risk of water inrush.
[0004] Therefore, in the field of deep mining, there has long been a lack of a collaborative treatment method that can simultaneously relieve the high stress and high water pressure of fault zones from the source. This is a core technical pain point that urgently needs to be solved. Summary of the Invention
[0005] The purpose of this invention is to provide a method for fracturing, water control, and scour prevention in the deep region of a hard fault. This invention solves the problems existing in the prior art by implementing directional hydraulic fracturing in the deep region of a hard fault (the fault location at a certain distance from the bottom of the coal seam being mined), artificially creating a fracturing drainage network, and connecting the fracturing drainage network to the diversion borehole system.
[0006] To achieve the above objectives, the present invention provides the following solution: a method for fracturing and controlling water flow to prevent erosion in deep regions of hard faults, comprising the following steps: S1. Geological exploration and hydraulic fracturing location determination: Locating the location of hydraulic fracturing and determining the fracturing layer; S2. Construction of hydraulic fracturing drainage network: Drill holes at the fracturing location and perform segmented directional hydraulic fracturing to construct a fracturing drainage network; S3. Set up a drainage borehole system: By constructing a drainage borehole system, the borehole terminals are connected to the fracturing drainage network to form a drainage system for hard rock faults; S4. Construct a collaborative prevention and control system: Controllable drainage is carried out through a drainage borehole system to simultaneously reduce water pressure and stress in the fault zone and construct a collaborative prevention and control system; S5. Effect monitoring and system optimization: Dynamically optimize drainage strategies and fracturing parameters based on monitoring results to ensure that the prevention and control system works in a coordinated manner.
[0007] Preferably, geological exploration uses a combination of geophysical exploration and drilling verification to accurately determine the spatial distribution, mechanical properties, and hydrogeological characteristics of hard faults.
[0008] Preferably, the location of hydraulic fracturing is determined by geological exploration results, and a pre-fracturing area is determined in the deep region of the fault. The pre-fracturing area should be located below the bottom plate of the coal seam being mined and below the key aquitard, so that the fracturing drainage network can effectively intercept water from the aquifer.
[0009] Preferably, horizontally oriented fracturing holes are constructed at suitable locations on the ground or downhole toward a defined pre-fracturing zone, and the fracturing holes pass through the pre-fracturing zone.
[0010] Preferably, the hydraulic fracturing system is used to carry out segmented fracturing operations through the hydraulic fracturing drill rod, and the inter-segment isolation is achieved by the sealing device to complete the construction of the fracturing drainage network.
[0011] Preferably, during the hydraulic fracturing process, the hydraulic fracturing system controls the injection pressure, flow rate, and the amount of fracturing fluid containing temporary plugging agent to promote the formation of multi-directionally expanding fractures in the rock mass, thereby constructing a three-dimensional fracturing and drainage network with the fracturing hole as the main trunk and multiple radial fractures as branches.
[0012] Preferably, at least two inclined hydraulic fracturing drainage boreholes are constructed from the underground roadway, and the locations of the inclined hydraulic fracturing drainage boreholes penetrate the core area of the fracturing drainage network to form a drainage system.
[0013] Preferably, an automatic control drainage valve and a multi-parameter sensor group are installed at the orifice of the inclined hydraulic fracturing drainage borehole to monitor parameters such as water pressure and flow rate and control the drainage process.
[0014] Preferably, a multi-parameter sensor array is used to monitor the water pressure changes in the fault zone in real time and feed the data back to the control system to form a collaborative prevention and control system.
[0015] Preferably, as the working face advances and the goaf forms, indicators such as microseismic activity, water pressure changes, and roadway deformation are continuously monitored; and drainage strategies and fracturing parameters are dynamically optimized based on the monitoring results.
[0016] The present invention discloses the following technical effects: This invention achieves a fundamental shift from passive disaster response to proactive source control. By constructing a pre-built fracturing and drainage network, this invention proactively transforms potential disaster sources in hard faults into pressure-unloading zones with reduced risks. It proactively releases stress and water energy accumulated within the fault zone before mining activities take effect, transforming post-event emergency response into pre-event intervention.
[0017] Meanwhile, in terms of coordinated control, this invention significantly increases the permeability of the fault, enabling the slow and controllable release of high-pressure water, fundamentally preventing the sudden occurrence of water inrush disasters; and through the fracturing and drainage network, it significantly weakens the mechanical strength of the fault, causing it to lose its ability to accumulate high energy, thereby effectively suppressing strong mine earthquakes and rockbursts.
[0018] This invention simultaneously addresses two types of major disasters, significantly reducing the life-cycle cost of mine disaster prevention systems and achieving a high degree of unity between safety and economic benefits. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a flowchart of the present invention; Figure 2 This is a layout diagram of the present invention; Among them, 1. Coal seam; 2. Hard fault; 3. Fracturing drainage network; 4. Sealing device; 5. Fracturing hole; 6. Coal seam water guiding channel; 7. Hydraulic fracturing drill rod; 8. Automatic control drainage valve; 9. Multi-parameter sensor group; 10. Hydraulic fracturing system; 11. Goaf; 12. Working face; 13. Aquifer; 14. Floor water guiding channel; 15. Inclined hydraulic fracturing diversion borehole; 16. Fault water guiding channel; 17. Aquifer water source; 18. Aquitard. Detailed Implementation
[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0023] Reference Figures 1 to 2 This invention provides a method for fracturing and controlling water flow to prevent erosion in deep regions of hard faults, comprising the following steps: S1. Geological exploration and hydraulic fracturing location determination: Locate the hydraulic fracturing location and determine the fracturing layer; further optimize the scheme; the geological exploration uses a combination of geophysical exploration and drilling verification to accurately determine the spatial distribution, mechanical properties and hydrogeological characteristics of the hard fault 2.
[0024] By combining geophysical exploration with drilling, the spatial distribution of the hard fault was accurately located. Surface 3D seismic exploration was used to macroscopically delineate the initial strike, dip, and potential impact range of the fault. Based on the geophysical exploration results, directional control boreholes were designed for directional drilling verification in key suspected areas. By extracting rock cores, the mechanical properties of the fault (such as siliceous cement strength), structural features, and water conductivity were directly observed, further determining the structure and rock mechanical properties of hard fault 2.
[0025] S2. Construction of hydraulic fracturing drainage network 3: Drill holes at the fracturing location and perform segmented directional hydraulic fracturing to construct fracturing drainage network 3; further optimize the scheme, determine the hydraulic fracturing location based on geological exploration results, determine the pre-fracturing area in the deep region of the fault, the pre-fracturing area should be located below the bottom plate of the mining coal seam 1 and below the key aquitard 18, so that fracturing drainage network 3 can effectively intercept the water body from the aquifer water source 17 of the aquifer 13.
[0026] To further optimize the scheme, horizontally oriented fracturing holes 5 are constructed at suitable locations on the ground or underground towards the determined pre-fracturing zone, and the fracturing holes 5 pass through the pre-fracturing zone.
[0027] The scheme was further optimized by using the hydraulic fracturing drill rod 7 of the hydraulic fracturing system 10 to carry out segmented fracturing construction, and using the sealing device 4 to achieve inter-segment isolation, thus completing the construction of the fracturing drainage network 3.
[0028] Further optimization of the scheme: during the hydraulic fracturing process of the hydraulic fracturing drill pipe 7, the hydraulic fracturing system 10 controls the injection pressure, discharge rate and the fracturing fluid with added temporary plugging agent, so as to promote the formation of multi-directionally expanding fractures in the rock mass and construct a three-dimensional fracturing and drainage network 3 with the fracturing hole 5 as the main trunk and multiple radial fractures as branches.
[0029] High-precision directional drilling technology is used to construct horizontal fracturing holes 5 from the ground or underground roadway to the pre-determined deep fracturing area of the fault. The trajectory of the fracturing holes 5 needs to accurately cross the pre-fracturing zone and extend as far as possible along the fault strike or the direction of minimum principal stress to maximize the fracturing effect.
[0030] In the fractured borehole 5, a hole sealer 4 is used for segmented hydraulic fracturing. After drilling the fractured borehole 5, the hydraulic fracturing drill rod 7 is left directly inside the fault to prevent deformation and blockage of the fractured borehole 5, and it can also serve as a stable channel for subsequent efficient water pumping; forming a three-dimensional fracturing and drainage network 3 with the fractured borehole 5 as the main trunk and multiple radial fractures as branches. The fracturing and drainage network 3 can effectively improve the permeability of the fault zone and form a preferential flow channel for groundwater.
[0031] The hydraulic fracturing parameters are as follows: Injection pressure: 1.2-1.5 ( (This represents the minimum horizontal principal stress in the target area).
[0032] Fracturing fluid: Add temporary plugging agent to promote multi-directional extension of fractures.
[0033] S3. Setting up a drainage borehole system: By constructing a drainage borehole system, the borehole terminals are connected to the fracturing drainage network 3 to form a hard rock fault drainage system; the scheme is further optimized by constructing at least two inclined hydraulic fracturing drainage boreholes 15 from the underground roadway, and the location of the inclined hydraulic fracturing drainage boreholes 15 penetrates the core area of the fracturing drainage network 3. At the same time, coal seam water guiding channels 6, floor water guiding channels 14, and fault water guiding channels 16 are also set up; the drainage system is formed by the coal seam water guiding channels 6, floor water guiding channels 14, inclined hydraulic fracturing drainage boreholes 15, and fault water guiding channels 16.
[0034] Depending on the water content in the fault, large-diameter inclined hydraulic fracturing drainage boreholes 15 are drilled again from the main underground roadway or dedicated chamber to the already formed fracturing drainage network 3. The endpoint of the inclined hydraulic fracturing drainage boreholes 15 must be located in the core area of the fracturing drainage network 3 in three-dimensional space and maintain a certain distance. The two promote each other and form the best drainage effect.
[0035] To further optimize the scheme, an automatic control drainage valve 8 and a multi-parameter sensor group 9 are installed at the orifice of the inclined hydraulic fracturing drainage borehole 15 to monitor parameters such as water pressure and flow rate and control the drainage process.
[0036] S4. Construct a collaborative prevention and control system: Controllable drainage is carried out through a drainage borehole system to simultaneously reduce water pressure and stress in the fault zone, thus constructing a collaborative prevention and control system; further optimize the scheme by using a multi-parameter sensor group 9 to monitor changes in water pressure in the fault zone in real time and feed the data back to the control system to form a collaborative prevention and control system.
[0037] By setting a reasonable safe water pressure threshold, when the monitored value exceeds the threshold, the drain valve 8 is automatically controlled to increase its opening to enhance drainage; when the water pressure is stable within the safe range, the valve opening of the drain valve 8 is automatically controlled to maintain balanced drainage.
[0038] In this process, the fracturing hydrophobic network 3 plays two key roles simultaneously: Water control function: to guide the water body of the aquifer water source 17 in the fault zone and its associated aquifer 13 to the diversion system, so as to prevent it from suddenly rushing into the mining space through the fault water diversion channel 16 or the bottom plate water diversion channel 14.
[0039] Anti-rockburst effect: By fracturing the fractures, the overall mechanical strength of the hard fault 2 is weakened, and the accumulated elastic energy is released, effectively suppressing strong mine shocks and rockbursts induced by mining stress.
[0040] The fracturing drainage network 3, generated by fracturing, has a high conductivity and permeability far exceeding that of the original fault medium, creating a low-resistance pumping channel for groundwater flow. This allows water to be actively guided into the fracturing drainage network 3 before or during mining operations, where it can be pumped out, thus avoiding the risk of random water inrushes at any weak point in the fault.
[0041] Furthermore, the fracturing hydrophobic network 3, as a macroscopic "artificial weak surface" or "damaged zone," has a mechanical strength far lower than that of an intact fault.
[0042] During the evolution of the stress field during mining, the fracturing hydrophobic network 3 becomes a buffer zone where stress is preferentially concentrated and released in advance; energy is dissipated through the micro-fractures of the rock mass and the slight opening of the fractures, thereby preventing energy from accumulating to dangerous levels in other areas of the fault and causing it to lose its ability to generate strong impact dynamic loads.
[0043] S5. Effect monitoring and system optimization: Dynamically optimize drainage strategies and fracturing parameters based on monitoring results to ensure that the control system works in a coordinated manner.
[0044] To further optimize the plan, as working face 12 advances and goaf 11 forms, we will continuously monitor indicators such as microseismic activity, water pressure changes, and roadway deformation; and dynamically optimize drainage strategies and fracturing parameters based on the monitoring results.
[0045] This invention achieves a fundamental shift from passive disaster response to proactive source control. Through the pre-constructed fracturing and drainage network 3, this invention can effectively transform the potential disaster source of the hard fault 2 into a pressure unloading zone with reduced risk, proactively releasing the stress and water energy accumulated in the fault zone before mining activities take effect, thus transforming post-event emergency response into pre-event intervention.
[0046] Meanwhile, in terms of coordinated control, this invention significantly increases the permeability of the fault, enabling the slow and controllable release of high-pressure water, fundamentally avoiding the sudden occurrence of water inrush disasters; and through the fracturing and hydrophobic network 3, it significantly weakens the mechanical strength of the fault, causing it to lose its ability to accumulate high energy, thereby effectively suppressing strong mine earthquakes and rockbursts.
[0047] This invention simultaneously addresses two types of major disasters, significantly reducing the life-cycle cost of mine disaster prevention systems and achieving a high degree of unity between safety and economic benefits.
[0048] This invention achieves coordinated prevention and control of water inrush and rock burst disasters under hard fault conditions, forming a complete, efficient, and safe technical system for disaster prevention and control in deep coal seam mining.
[0049] This invention aims to overcome the limitations of existing technologies in "single-hazard management" of hard faults, providing a fundamental solution for collaborative prevention and control from the source of disasters. Its core lies in creatively implementing directional hydraulic fracturing in the deep regions of hard faults to construct an artificial water-conducting and pressure-relieving structure integrating "stress transfer, hydraulic drainage, and energy release." This structure can reconstruct the stress field, directionally releasing the high-concentration stress accumulated within the fault through a hydraulic fracturing network, thereby eliminating the driving force of rockbursts. Simultaneously, it transforms the seepage field, converting weakly water-conducting faults into highly efficient water-conducting fracturing and drainage networks, providing controllable drainage channels for high-pressure water bodies, significantly reducing the probability of sudden water inrushes, and providing conditions for continuous and controllable water release. Furthermore, it simultaneously dissipates the elastic energy of the rock mass and the potential energy of the water body, fundamentally solving the disaster chain of "high stress-high water pressure" coupling, and achieving an optimized transformation of disaster management from passive response to active intervention, and from single-hazard management to collaborative prevention and control, providing core technological support for the safe and efficient mining of deep, high-risk coal seams.
[0050] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0051] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A method for fracturing and controlling water flow to prevent erosion in deep regions of hard faults, characterized in that: Includes the following steps: S1. Geological exploration and hydraulic fracturing location determination: Locating the location of hydraulic fracturing and determining the fracturing layer; S2. Construction of hydraulic fracturing drainage network (3): Drill holes at the fracturing location and perform segmented directional hydraulic fracturing to construct the fracturing drainage network (3). S3. Set up a drainage borehole system: By constructing a drainage borehole system, the borehole terminal is connected to the fracturing drainage network (3) to form a hard rock fault drainage system; S4. Construct a collaborative prevention and control system: Controllable drainage is carried out through a drainage borehole system to simultaneously reduce water pressure and stress in the fault zone and construct a collaborative prevention and control system. S5. Effect monitoring and system optimization: Dynamically optimize drainage strategies and fracturing parameters based on monitoring results to ensure that the prevention and control system works in a coordinated manner.
2. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 1, characterized in that: Geological exploration uses a combination of geophysical exploration and drilling verification to accurately determine the spatial distribution, mechanical properties and hydrogeological characteristics of hard faults (2).
3. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 2, characterized in that: The location of hydraulic fracturing is determined by the results of geological exploration. The pre-fracturing area is determined in the deep region of the fault. The pre-fracturing area should be located below the bottom plate of the coal seam (1) and below the key aquitard (18) so that the fracturing drainage network (3) can effectively intercept water from the aquifer (13).
4. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 3, characterized in that: Horizontally oriented fracturing holes (5) are constructed at appropriate locations on the ground or downhole towards the determined pre-fracturing zone, and the fracturing holes (5) pass through the pre-fracturing zone.
5. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 4, characterized in that: The hydraulic fracturing system (10) uses the hydraulic fracturing drill rod (7) to carry out segmented fracturing construction, and uses the sealing device (4) to achieve inter-segment isolation, thus completing the construction of the fracturing drainage network (3).
6. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 5, characterized in that: During the hydraulic fracturing process of the hydraulic fracturing drill pipe (7), the hydraulic fracturing system (10) controls the injection pressure, discharge rate and the fracturing fluid with added temporary plugging agent, so as to promote the formation of multi-directional expansion fractures in the rock mass and construct a three-dimensional fracturing drainage network (3) with the fracturing hole (5) as the main trunk and multiple radial fractures as branches.
7. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 6, characterized in that: At least two inclined hydraulic fracturing drainage boreholes (15) are constructed from the underground roadway, and the location of the inclined hydraulic fracturing drainage boreholes (15) penetrates the core area of the fracturing drainage network (3) to form a drainage system.
8. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 7, characterized in that: An automatic control drain valve (8) and a multi-parameter sensor group (9) are installed at the orifice of the inclined hydraulic fracturing drainage borehole (15) to monitor parameters such as water pressure and flow rate and control the drainage process.
9. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 8, characterized in that: The multi-parameter sensor group (9) monitors the water pressure changes in the fault zone in real time and feeds the data back to the control system to form a collaborative prevention and control system.
10. The method for fracturing, water control, and scour prevention in deep regions of hard faults according to claim 9, characterized in that: As the working face (12) advances and the goaf (11) forms, we continuously monitor indicators such as microseismic activity, water pressure changes and roadway deformation; and dynamically optimize drainage strategies and fracturing parameters based on the monitoring results.