Method, device and equipment for determining hydraulic fracturing pressure relief parameters and storage medium

Abstract

The invention relates to the technical field of coal mining, in particular to a hydraulic fracturing pressure relief parameter determination method and device, equipment and a storage medium. According to the method for determining the hydraulic fracturing pressure relief parameters, rock stratum data and rock mechanical parameters of a top plate of a stope to be fractured are collected, an appropriate fracturing layer position is selected, a corresponding fracturing scheme is selected according to the obtained stress state, and fracturing parameters including the drilling length, the fracturing segment length and the pressure and flow needed by fracturing are determined. According to the method, the hard roof can be effectively weakened, energy accumulation is reduced, stress concentration is reduced, rock burst accidents are prevented and relieved, and the purpose of safe production of a coal mine is achieved. Through accurate hydraulic fracturing parameter selection, the construction scheme can be optimized, the hydraulic fracturing efficiency and effect are improved, and the method has important engineering significance and practical application value for coal mine safety production.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to a method, device, equipment and storage medium for determining hydraulic fracturing pressure relief parameters. Background Art

[0002] During coal mining, the hard roof, due to its high strength and thickness, often forms a large area of ​​overhang after coal seam mining, which is difficult to collapse on its own, resulting in energy accumulation and stress concentration, thus inducing tunnel impact rock pressure accidents. Once these hard roofs suddenly collapse, they will cause a strong impact airflow, posing a serious threat to underground production safety.

[0003] Based on the fact that hydraulic fracturing changes the hard roof structure, the construction plan and parameters of hydraulic fracturing are determined. This method can more effectively weaken the hard roof, reduce energy accumulation, reduce stress concentration, prevent and reduce rock burst accidents, and achieve the goal of safe production in coal mines.

[0004] Although hydraulic fracturing technology has shown its effectiveness in theory and practice, it is often difficult to select construction parameters in actual construction. Due to the lack of accurate parameter selection methods, the construction effect may be directly affected, resulting in unstable hydraulic fracturing effects and failure to achieve the expected roof weakening effect. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem of inaccurate selection of hydraulic fracturing parameters in the prior art.

[0006] In order to solve the above technical problems, the present invention provides a method for determining hydraulic fracturing pressure relief parameters, comprising:

[0007] Collect rock formation data and rock mechanics parameters of the roof of the mining area to be fractured;

[0008] Selecting a target layer for fracturing according to the rock formation data and the rock mechanics parameters;

[0009] Perform similar simulation tests and numerical simulation analysis on the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters;

[0010] Based on the target fracturing layer, a corresponding fracturing scheme is selected according to the stress state obtained from the similar simulation test and numerical simulation analysis, and fracturing parameters are determined.

[0011] Preferably, the acquisition of rock formation data and rock mechanics parameters of the top plate of the mining area to be fractured includes:

[0012] Collect the thickness of each rock layer overlying the roof;

[0013] Use SEM scanning electron microscope scanning, CT scanning or XRD analysis to obtain the rock components and crystal phases of each rock layer;

[0014] Obtain the ground stress state of each rock layer in the overlying roof by hollow inclusion method or hydraulic fracturing method;

[0015] Rock mechanics tests were carried out based on the cores obtained by drilling into each rock layer of the overlying roof to obtain the rock mechanics parameters of each rock layer.

[0016] Preferably, the rock mechanics parameters of each rock formation include rock density, uniaxial compressive strength, elastic modulus, Poisson's ratio, porosity and anisotropic wave velocity.

[0017] Preferably, the geostress state includes maximum horizontal principal stress, minimum horizontal principal stress, vertical stress and stress deflection angle.

[0018] Preferably, the selecting of the target fracturing layer comprises:

[0019] Determine, based on the rock formation data and the rock mechanics parameters, that the nth layer in the overlying roof rock formation is subjected to the loads from the nth layer to the mth layer, and determine, in combination with the characteristic conditions of the hard rock formation, the key layer of the overlying roof as the target layer for fracturing, or,

[0020] A similar simulation test platform is constructed based on the rock formation data and the rock mechanics parameters, and a hard and difficult-to-collapse rock formation is determined as a target layer for fracturing by monitoring the collapse morphology and displacement of each rock formation on the overlying roof, or,

[0021] A numerical simulation model is constructed based on the rock formation data and the rock mechanics parameters, and the collapse morphology, stress field, displacement field and plastic zone range of the overlying roof after fracturing are determined through numerical simulation analysis, thereby determining the target stratum for fracturing, or,

[0022] The height required for the roof collapse waste rock to completely fill the goaf is determined based on the rock formation data and the rock mechanics parameters, and the target layer for fracturing is determined based on the height.

[0023] Preferably, the similarity simulation test and numerical simulation analysis of the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters include:

[0024] Based on the rock formation data and the rock mechanics parameters, similar simulation tests and numerical simulation analyses are carried out on the rock formations of the overlying roof to determine the periodic fracture steps and fracture structures of the rock formations of the overlying roof, and to analyze the scope and causes of the strong mine pressure.

[0025] Preferably, based on the target fracturing layer, selecting a corresponding fracturing scheme according to the stress state obtained by the similar simulation test and numerical simulation analysis, and determining fracturing parameters include:

[0026] The drilling length is determined according to the operating capacity of the underground construction equipment, the geological conditions of the mining site, the height of the target fracturing layer and the range of hard rock layers and the range of strong mine pressure;

[0027] According to the on-site construction conditions, select the number of drilling and fracturing times within the range of strong mine pressure;

[0028] Determine the length of the fracturing segment according to the rock formation breaking step after fracturing;

[0029] Determining the fracturing pressure based on the rock formation data and the rock mechanical parameters using the Hubbert-Willis model taking into account Darcy flow;

[0030] Based on the rock formation data and the rock mechanics parameters, the fracturing flow rate is determined to ensure that the cracks extend to a predetermined range.

[0031] The present invention also provides a hydraulic fracturing pressure relief parameter determination device, comprising:

[0032] A data acquisition module, used to collect rock formation data and rock mechanics parameters of the top plate of the mining area to be fractured;

[0033] A fracturing layer determination module, used for selecting a fracturing target layer according to the rock formation data and the rock mechanics parameters;

[0034] A simulation analysis module, used for performing similar simulation tests and numerical simulation analysis on the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters;

[0035] The parameter determination module is used to select a corresponding fracturing scheme based on the fracturing target layer and the stress state obtained by the similar simulation test and numerical simulation analysis, and determine the fracturing parameters.

[0036] The present invention also provides a hydraulic fracturing pressure relief parameter determination device, comprising:

[0037] Memory for storing computer programs;

[0038] A processor is used to implement the above-mentioned method steps for determining hydraulic fracturing pressure relief parameters when executing the computer program.

[0039] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for determining hydraulic fracturing decompression parameters are implemented.

[0040] The above technical solution of the present invention has the following advantages compared with the prior art:

[0041] The method for determining hydraulic fracturing pressure relief parameters of the present invention collects rock formation data and rock mechanics parameters of the roof of the mining area to be fractured, selects a suitable fracturing layer, and selects a corresponding fracturing scheme according to the obtained stress state to determine the fracturing parameters, including the length of the borehole, the segment length of the fracturing, and the pressure and flow required for the fracturing. This method can more effectively weaken the hard roof, reduce energy accumulation, reduce stress concentration, prevent and reduce rock burst accidents, and achieve the goal of safe production in coal mines. Through accurate selection of hydraulic fracturing parameters, the present invention can optimize the construction plan, improve the efficiency and effect of hydraulic fracturing, and has important engineering significance and practical application value for safe production in coal mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0043] Figure 1 It is a flow chart of a method for determining hydraulic fracturing pressure relief parameters provided by the present invention;

[0044] Figure 2 It is a flow chart of a method for determining hydraulic fracturing pressure relief parameters according to an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the structure of the stope before fracturing;

[0046] Figure 4 It is a schematic diagram of the structure of the stope after fracturing;

[0047] Description of the accompanying drawings: 1-coal seam, 2-direct roof, 3-gangue in the goaf, 4-hard roof of the suspended roof, 5-support pressure curve above the coal seam before fracturing, 6-overlying load curve of the hard roof before fracturing, 7-support pressure curve above the coal seam after fracturing, 8-overlying load curve of the hard roof after fracturing, 9-broken hard rock layer after fracturing, 10-fracturing borehole, 11-segmented fracturing length. DETAILED DESCRIPTION

[0048] The core of the present invention is to provide a method, device, equipment and computer storage medium for determining hydraulic fracturing pressure relief parameters, which effectively improves the accuracy of hydraulic fracturing parameter selection.

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0050] The purpose of the present invention is to provide a method for determining hydraulic fracturing pressure relief parameters, by generating fracturing cracks in the hard roof, dividing the hard roof into several independent rock masses, changing the rock layer structure of the hard roof so that the hard roof can collapse in time, thereby avoiding the hard roof hanging in a large area without falling and suddenly collapsing, causing the hazards of strong impact airflow and strong mine pressure.

[0051] Please refer to Figure 1 , Figure 1 This is a flow chart of a method for determining hydraulic fracturing pressure relief parameters provided by the present invention; the specific operation steps are as follows:

[0052] S101: Collecting rock formation data and rock mechanics parameters of the top plate of the mining area to be fractured;

[0053] S102: selecting a target layer for fracturing according to the rock formation data and the rock mechanics parameters;

[0054] S103: performing similar simulation tests and numerical simulation analysis on the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters;

[0055] S104: Based on the target fracturing layer, a corresponding fracturing scheme is selected according to the stress state obtained from the similar simulation test and the numerical simulation analysis, and fracturing parameters are determined.

[0056] like Figure 2 As shown, Figure 2 The present invention provides a flowchart of a method for determining hydraulic fracturing pressure relief parameters according to an embodiment of the present invention.

[0057] like Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of the mining area before fracturing.

[0058] like Figure 4 As shown, Figure 4 It is a schematic diagram of the structure of the mining area after fracturing.

[0059] Based on the above embodiments, this embodiment describes step S101 in detail:

[0060] Collect the thickness of each rock layer overlying the roof;

[0061] Use SEM scanning electron microscope scanning, CT scanning or XRD analysis to obtain the rock components and crystal phases of each rock layer;

[0062] Obtain the ground stress state of each rock layer of the overlying roof through the hollow inclusion method or hydraulic fracturing method, including the maximum horizontal principal stress, minimum horizontal principal stress, vertical stress and stress deflection angle, etc.;

[0063] · Obtain rock cores through ground drilling. Perform rock mechanics tests on the rock cores obtained by drilling holes in the rock layers of the overlying roof to obtain rock mechanics parameters of each rock layer, including: rock density, uniaxial compressive strength, elastic modulus, Poisson's ratio, porosity and anisotropic wave velocity, etc.;

[0064] Among them, the uniaxial compressive strength can be calculated by the following formula:

[0065]

[0066] Where P is the maximum axial pressure at failure, and A is the cross-sectional area of ​​the specimen.

[0067] Anisotropic wave velocity can be measured by ultrasonic velocimetry.

[0068] In a specific application, the main coal seam of a coal mine is No. 2 coal, with a burial depth of about 400m, an inclination of 1° to 3°, a nearly horizontal coal seam, a coal thickness of 3.80 to 5.50m, and an average coal thickness of 4.5m. The coal samples and roof cores obtained were prepared into standard mechanical test specimens using rock drilling machines and cutting machines, and rock mechanical properties were tested in the laboratory using the MTS electro-hydraulic servo rock mechanics experimental system to obtain rock density, uniaxial compressive strength, elastic modulus, Poisson's ratio and other parameters, and the mineral composition and content of the rock samples were analyzed by XRD.

[0069] Based on the above embodiments, this embodiment describes step S102 in detail:

[0070] The method for selecting the fracturing layer includes but is not limited to a combination of one or more of the following methods:

[0071] Determine, based on the rock formation data and the rock mechanics parameters, that the nth layer in the overlying roof rock formation is subjected to the loads from the nth layer to the mth layer, and determine, in combination with the characteristic conditions of the hard rock formation, the key layer of the overlying roof as the target layer for fracturing;

[0072] The hardness of the overlying roof rock layer can be calculated by the following formula:

[0073] The nth layer in the overlying roof rock layer bears the load of layers n to m (q m ) n for:

[0074]

[0075] In the formula, E i represents the elastic modulus of the i-th rock layer, GPa; γ i is the bulk density of the i-th rock layer, kg / m3; h i is the thickness of the i-th rock layer, m. The above rock layer thickness and rock parameters can be obtained through step S101.

[0076] If the m+1 layer is a hard rock layer, it should have the following characteristics:

[0077] (q m ) n >(q m+1 ) n

[0078] The breaking distance of hard rock can be calculated by the following formula:

[0079]

[0080] ·Build a similar simulation test platform based on the rock formation data and the rock mechanics parameters, and determine the hard and difficult-to-collapse rock formation as the target layer for fracturing by monitoring the collapse morphology and displacement of each rock formation on the overlying roof;

[0081] ·Build a numerical simulation model based on the rock formation data and the rock mechanics parameters, and determine the collapse morphology, stress field, displacement field and plastic zone range of the overlying roof after fracturing through numerical simulation analysis, and then determine the target stratum for fracturing;

[0082] According to the rock mechanical parameters, rock components and crystal phases obtained in step S101, a similar simulation test platform is constructed, and a numerical simulation model is constructed; wherein the numerical simulation software may be UDEC, 3DEC, etc.;

[0083] The hard and difficult-to-collapse rock layer and the roof structure after fracturing are determined through laboratory similarity simulation tests and numerical simulations. The similarity simulation test can determine the target layer for fracturing by observing the collapse morphology of the overlying rock layer and displacement monitoring, and the numerical simulation can determine the target layer for fracturing by analyzing the collapse morphology of the roof, stress field, displacement field, plastic zone range, etc. Among them, the discrete element simulation software UDEC can be selected for numerical simulation for excavation simulation.

[0084] Determine the height required for the roof collapse waste rock to completely fill the goaf according to the rock formation data and the rock mechanics parameters, and determine the target layer for fracturing according to the height.

[0085] The height required for the roof collapse to completely fill the goaf can be calculated using the following formula:

[0086]

[0087] In the formula, H M is the thickness of the coal seam, m; ΔH1 is the amount of roof subsidence, m; ΔH2 is the amount of bottom plate uplift, m; K is the rock expansion coefficient, usually taken as 1.1-1.3.

[0088] It should be noted that the above-mentioned methods for determining the fracturing layer are not independent of each other. In actual projects, multiple methods should be adopted to verify each other, and the results of multiple methods should be combined to determine the final construction plan.

[0089] In a specific application, the target stratum for fracturing was finally determined to be the rock stratum 38-46 m above the coal seam, so the drilling position was selected to be 43 m above the coal seam.

[0090] The present invention adopts multiple means such as theoretical calculation, similar simulation test, numerical simulation and on-site monitoring to design the target layer of hydraulic fracturing, so that the design result is more scientific and reasonable. Specifically, the present invention constructs a similar simulation test platform by theoretically calculating the hard rock layer of the overlying rock layer, and constructs a numerical simulation model through discrete element numerical simulation software UDEC. Through theoretical calculation, similar simulation test and numerical simulation results, the fracture step and fracture structure of the roof are comprehensively determined, the cause of strong mine pressure is analyzed, and the target fracturing rock layer is selected. This design method combining multiple methods not only improves the accuracy of the selection of the target layer of hydraulic fracturing, but also enhances the reliability and safety of the construction scheme. Through this multi-dimensional analysis and design, the present invention can more accurately determine the fracturing layer, thereby improving the effect of hydraulic fracturing, reducing construction risks, and has important guiding significance for coal mine safety production.

[0091] In step S102, the target layer for fracturing can also be determined by identifying the spatial geometric structural characteristic parameters of the overburden "stress arch" and "fracture arch" of the working face and the position of the key layer within the influence range.

[0092] In step S102, the hydraulic fracturing target layer may also be determined by numerical simulation method according to the unbalanced force distribution information, and the unbalanced force in the lower area of ​​the hydraulic fracturing target layer is greater than the unbalanced force in the upper area.

[0093] Based on the above embodiments, this embodiment describes step S103 in detail:

[0094] Based on the rock formation data and the rock mechanics parameters, similar simulation tests and numerical simulation analyses are carried out on the rock formations of the overlying roof to determine the periodic fracture steps and fracture structures of the rock formations of the overlying roof, and to analyze the scope and causes of the strong mine pressure.

[0095] Based on the above embodiments, this embodiment describes step S104 in detail:

[0096] Determine the drilling length according to the operating capacity of the underground construction equipment, the geological conditions of the mining site, the height of the target fracturing layer, the range of hard rock layers, and the range of strong mine pressure;

[0097] The drilling length should be determined comprehensively based on the operating capacity of the underground construction equipment, the geological conditions of the mining site, the height of the fracturing layer, the range of the hard rock layer obtained in step S103, and the range of the strong mine pressure.

[0098] · According to the on-site construction conditions, select the number of drilling and fracturing within the range of strong mine pressure;

[0099] According to the on-site construction conditions, one-time drilling and fracturing or multiple drilling and fracturing can be selected within the range where strong mine pressure appears.

[0100] In a specific application, according to the capacity of the on-site underground construction equipment and the geological conditions of the mining site, the length of the fracturing drilling hole is determined to be 500m, the length of the horizontal hole is 350m, the length of the turning is 150m, and the direction along the working face is determined.

[0101] Determine the length of the fracturing segment according to the rock formation breaking step after fracturing;

[0102] Through the similar simulation test and numerical simulation in step S103, the rock formation breaking step distances before and after fracturing are obtained, and the fracturing segment length is the rock formation breaking step distance after fracturing.

[0103] In a specific application, according to the roof periodic breaking step in step S103, the staged fracturing length is determined to be 19-21 m, and backward primary fracturing is adopted.

[0104] Determining the fracturing pressure based on the rock formation data and the rock mechanical parameters using the Hubbert-Willis model taking into account Darcy flow;

[0105] The fracturing pressure can be calculated by the Hubbert-Willis (HW) model considering Darcy flow: b =3σ h -σ H +σ t -P0

[0106] In the formula, p b is the burst pressure, σ h is the minimum principal stress perpendicular to the drilling direction, σ H is the maximum principal stress perpendicular to the drilling direction, σ t is the tensile strength of the rock formation, and P0 is the pore water pressure of the rock formation.

[0107] It should be noted that the fracturing pressure should be appropriately greater than the calculation result of the above formula so that the range of hydraulic crack expansion can change the structure of the hard rock formation.

[0108] In a specific application, based on the results of on-site geostress investigation, the formula was substituted for calculation, and the final fracturing pressure was 40MPa. To ensure the construction effect, the on-site fracturing equipment should reach a fracturing pressure of at least 50MPa.

[0109] Based on the rock formation data and the rock mechanics parameters, determine the fracturing flow rate to ensure that the cracks extend to a predetermined range.

[0110] The fracturing flow rate should ensure that the cracks extend to a predetermined range, and its influencing factors include rock layer thickness, pore water pressure and porosity, ground stress direction, etc. The specific parameters can be determined by laboratory similarity simulation tests and numerical simulations in step S103.

[0111] In a specific application, the fracturing flow rate should ensure that the cracks extend to a predetermined range, and its influencing factors include rock thickness, pore water pressure and porosity, ground stress direction, etc. To ensure that the fracturing construction completely cuts off the target rock formation, according to the parameters obtained in step S101, the fracturing flow rate is selected as 90L / min, and each fracturing period is 15min.

[0112] The present invention is based on the principle of hydraulic fracturing roof pressure relief, and from the perspective of hydraulic fracturing changing the roof structure, a clear hydraulic fracturing pressure relief parameter design method is proposed. The method optimizes the construction plan and improves the efficiency and effect of hydraulic fracturing by accurately selecting hydraulic fracturing parameters. Specifically, the present invention selects a suitable fracturing layer by collecting the rock formation data and rock mechanics parameters of the roof of the mining area to be fractured, and selects the corresponding fracturing plan according to the obtained stress state, and determines the fracturing parameters, including the length of the borehole, the segmented length of the fracturing, and the pressure and flow required for the fracturing. This method can more effectively weaken the hard roof, reduce energy accumulation, reduce stress concentration, prevent and reduce rock burst accidents, so as to achieve the goal of safe production in coal mines. Through accurate hydraulic fracturing parameter selection, the present invention can optimize the construction plan, improve the efficiency and effect of hydraulic fracturing, and has important engineering significance and practical application value for safe production in coal mines.

[0113] The embodiment of the present invention further provides a device for determining hydraulic fracturing pressure relief parameters; the specific device may include:

[0114] A data acquisition module, used to collect rock formation data and rock mechanics parameters of the top plate of the mining area to be fractured;

[0115] A fracturing layer determination module, used for selecting a fracturing target layer according to the rock formation data and the rock mechanics parameters;

[0116] A simulation analysis module, used for performing similar simulation tests and numerical simulation analysis on the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters;

[0117] The parameter determination module is used to select a corresponding fracturing scheme based on the fracturing target layer and the stress state obtained by the similar simulation test and numerical simulation analysis, and determine the fracturing parameters.

[0118] The hydraulic fracturing pressure relief parameter determination device of the present embodiment is used to implement the aforementioned hydraulic fracturing pressure relief parameter determination method. Therefore, the specific implementation method of the hydraulic fracturing pressure relief parameter determination device can be seen in the embodiment part of the hydraulic fracturing pressure relief parameter determination method mentioned above. For example, the data acquisition module, the fracturing layer determination module, the simulation analysis module, and the parameter determination module are respectively used to implement steps S101, S102, S103, and S104 in the aforementioned hydraulic fracturing pressure relief parameter determination method. Therefore, its specific implementation method can refer to the description of the corresponding various parts of the embodiment, and will not be repeated here.

[0119] A specific embodiment of the present invention further provides a hydraulic fracturing pressure relief parameter determination device, comprising: a memory for storing a computer program; and a processor for implementing the steps of the above-mentioned hydraulic fracturing pressure relief parameter determination method when executing the computer program.

[0120] A specific embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for determining hydraulic fracturing decompression parameters are implemented.

[0121] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0122] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0123] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0124] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0125] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for determining hydraulic fracturing pressure relief parameters, characterized in that: include: Collect rock formation data and rock mechanics parameters of the roof of the mining area to be fractured; Selecting a target layer for fracturing according to the rock formation data and the rock mechanics parameters; Perform similar simulation tests and numerical simulation analysis on the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters; Based on the target fracturing layer, a corresponding fracturing scheme is selected according to the stress state obtained from the similar simulation test and numerical simulation analysis, and fracturing parameters are determined.

2. The method for determining hydraulic fracturing pressure relief parameters according to claim 1, characterized in that: The acquisition of rock formation data and rock mechanics parameters of the top plate of the stope to be fractured includes: Collect the thickness of each rock layer overlying the roof; Use SEM scanning electron microscope scanning, CT scanning or XRD analysis to obtain the rock components and crystal phases of each rock layer; Obtain the ground stress state of each rock layer in the overlying roof by hollow inclusion method or hydraulic fracturing method; Rock mechanics tests were carried out based on the cores obtained by drilling into each rock layer of the overlying roof to obtain the rock mechanics parameters of each rock layer.

3. The method for determining hydraulic fracturing pressure relief parameters according to claim 2, characterized in that: The rock mechanics parameters of each rock layer include rock density, uniaxial compressive strength, elastic modulus, Poisson's ratio, porosity and anisotropic wave velocity.

4. The method for determining hydraulic fracturing pressure relief parameters according to claim 2, characterized in that: The geostress state includes the maximum horizontal principal stress, the minimum horizontal principal stress, the vertical stress and the stress deflection angle.

5. The method for determining hydraulic fracturing pressure relief parameters according to claim 1, characterized in that: The selection of the target layer for fracturing comprises: Determine, based on the rock formation data and the rock mechanics parameters, that the nth layer in the overlying roof rock formation is subjected to the loads from the nth layer to the mth layer, and determine, in combination with the characteristic conditions of the hard rock formation, the key layer of the overlying roof as the target layer for fracturing, or, A similar simulation test platform is constructed based on the rock formation data and the rock mechanics parameters, and a hard and difficult-to-collapse rock formation is determined as a target layer for fracturing by monitoring the collapse morphology and displacement of each rock formation on the overlying roof, or, A numerical simulation model is constructed based on the rock formation data and the rock mechanics parameters, and the collapse morphology, stress field, displacement field and plastic zone range of the overlying roof after fracturing are determined through numerical simulation analysis, thereby determining the target stratum for fracturing, or, The height required for the roof collapse waste rock to completely fill the goaf is determined based on the rock formation data and the rock mechanics parameters, and the target layer for fracturing is determined based on the height.

6. The method for determining hydraulic fracturing pressure relief parameters according to claim 1, characterized in that: The similarity simulation test and numerical simulation analysis of the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters include: Based on the rock formation data and the rock mechanics parameters, similar simulation tests and numerical simulation analyses are carried out on the rock formations of the overlying roof to determine the periodic fracture steps and fracture structures of the rock formations of the overlying roof, and to analyze the scope and causes of the strong mine pressure.

7. The method for determining hydraulic fracturing pressure relief parameters according to claim 6, characterized in that: The method of selecting a corresponding fracturing scheme based on the target fracturing layer and the stress state obtained by the similar simulation test and numerical simulation analysis, and determining fracturing parameters includes: The drilling length is determined according to the operating capacity of the underground construction equipment, the geological conditions of the mining site, the height of the target fracturing layer and the range of hard rock layers and the range of strong mine pressure; According to the on-site construction conditions, select the number of drilling and fracturing times within the range of strong mine pressure; Determine the length of the fracturing segment according to the rock formation breaking step after fracturing; Determining the fracturing pressure based on the rock formation data and the rock mechanical parameters using the Hubbert-Willis model taking into account Darcy flow; Based on the rock formation data and the rock mechanics parameters, the fracturing flow rate is determined to ensure that the cracks extend to a predetermined range.

8. A hydraulic fracturing pressure relief parameter determination device, characterized in that: include: A data acquisition module, used to collect rock formation data and rock mechanics parameters of the top plate of the mining area to be fractured; A fracturing layer determination module, used for selecting a fracturing target layer according to the rock formation data and the rock mechanics parameters; A simulation analysis module, used for performing similar simulation tests and numerical simulation analysis on the roof of the stope to be fractured according to the rock formation data and the rock mechanics parameters; The parameter determination module is used to select a corresponding fracturing scheme based on the fracturing target layer and the stress state obtained by the similar simulation test and numerical simulation analysis, and determine the fracturing parameters.

9. A hydraulic fracturing pressure relief parameter determination device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of a method for determining hydraulic fracturing decompression parameters as claimed in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for determining hydraulic fracturing decompression parameters as claimed in any one of claims 1 to 7 are implemented.

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