204 results about "Micro fracture" patented technology

The present invention relates to a pressure bearing permeation grouting strengthening test apparatus and a method. The apparatus mainly comprises a grouting bucket, a slurry storage device and a manual grouting pressurization device, wherein the grouting bucket comprises a base, a bucket body and a pressing head, a grouting hole is arranged in the base, and is connected with the slurry storage device through a high pressure soft pipe, the slurry storage device is provided with a piston, and the manual grouting pressurization device is placed below the piston. With the test apparatus, influence of axial pressure, confining pressure and other factors of the upper portion of the micro fracture (pores) geology on the grouting can be simulated; the grouting conditions of the geological bodies with different physical and mechanical properties under different grouting parameters and different grouting process conditions can be simulated so as to analyze a mechanism and an effect of grouting strengthening; and with the test apparatus, broken coal rock bodies, soil samples and sand samples can be made into complete samples, can be processed into standard samples through a cutting machine, and then are subjected to related uniaxial and triaxial tests. In addition, the test apparatus has characteristics of simple structure, easy manufacturing, low cost, easy operation, and reliable use.

The invention provides a simulation experiment method of coal seam hydraulic fracture, comprising the following steps of: (a) analyzing natural fracture shape characteristics of a coal rock in a stratum to be simulated, selecting a coal rock material for making a simulation specimen, processing the coal rock material into a hexahedral block according to the natural fracture shape characteristics,and selecting a coating layer carrying out external casting on the block to form the simulation specimen; (b) selecting fluorescent powder as a tracer, and then preparing fracturing fluid; and (c) performing a simulation fracturing experiment with the simulation specimen and the fracturing fluid and acquiring image information of a hydraulic fracture shape and a fracturing fluid swept region after the experiment. In terms of brittle and fragile coal rock with difficulty in processing, after the coating layer is cast by the method disclosed by the invention, the specimen has whole smooth and regular appearance, and the stratification and cutting positions of the coal rock can be well controlled. When the experiment result is acquired, the range of the hydraulic fracture can be clearly displayed by the fluorescent powder, and in particular the micro-fracture that cannot be viewed by the naked eyes can be displayed.

The invention relates to the technical field of hydraulic fracturing capacity increasing revamping of oil and gas reservoirs, in particular to a method suitable for effective flow guide for fractures in fracturing of a shale oil pool reservoir. The method includes the following steps that A, the reservoir is pretreated through acid liquor; B, the main fracture is constructed through low-viscosity fracturing fluid; C, the micro fractures and the branch fractures are opened by injecting low-viscosity slickwater; D, slugging is conducted by injecting low-viscosity acid liquor and low-viscosity slickwater alternately; E, low-viscosity slickwater carrying a proppant and low-viscosity fracturing fluid carrying a proppant are injected in sequence so as to support a micro fracture system and a branch fracture system, and the first proppant is different from the second proppant; F, intermediate-viscosity fracturing fluid carrying proppants is injected so as to support a main fracture system; and G, the fourth proppant in a shaft is completely displaced to the openings of the fractures by means of the low-viscosity slickwater.

The invention discloses a method for simulating offshore oilfield micro fracturing injection increase crack propagation on the basis of fluid-solid-heat coupling theory. The method comprises the following steps that geological characteristic parameters are obtained on the basis of offshore micro fracturing well geological data; a hydraulic crack propagation model is built, and fluid pressure and filter loss in a crack are obtained; on the basis of a reservoir matrix model, dynamically changing pore pressure in a reservoir is worked out; on the basis of elastic mechanics and permeation fluid mechanics, a pore elastic deformation relation between fluid and rock is built, that is to say, a fluid-solid coupling model is built, and by means of the calculated pore pressure, rock strain caused bythe fluid can be obtained; a heat effect relation between the temperature and the rock is built, a strain, porosity, permeability and temperature fluid-solid-heat coupling model is built, the permeability and porosity after coupling change are obtained, the pore pressure after three-field coupling change is obtained, the changed pore pressure reacts on a Darcy filtration model, and the crack extension dynamic of the next moment is obtained. According to construction and geological parameters, the dynamic extension situation of the hydraulic crack and real-time change situation of the reservoir parameters in the offshore micro fracturing well long-term injection increase process can be predicted according to the construction and geological parameters.

The invention provides a method of forming fractures by means of hydrofracturing assisted by alternate spraying of high- and low-temperature fluids in deep hot dry rock. The method herein includes: setting out a well network, and performing primary hydrofracturing to form main fractures; injecting a high-temperature high-pressure fluid and low-temperature water alternately into the main fractureswithin short alternate time; forming micro fractures in the rock at the surface of the main fractures under the thermodynamic action of a great temperature difference and the impact action of a jet; allowing multilevel fracturing to enable the micro fractures to further expand and form more micro fractures under the action of a low-temperature waterborne fracturing fluid and the action of high pressure; repeating until the main fractures and the micro fractures are in mutual lap joint and communication so that a fracture cluster and/or a fracture belt is formed between injection wells and production wells; injecting a sand-carrying fluid, a proppant and a displacing fluid, and closing the wells to complete fracture forming so as to construct an efficient heat exchange reservoir. The methodenables the quantity of the fractures to be significantly increased via the thermal stress action of the temperature difference, so that a fracture network is formed; heat exchange efficiency of a heat storage space is improved.

The invention discloses a volume fracturing method of deep shale gas multi-scale proppant packing. The volume fracturing method of deep shale gas multi-scale proppant packing comprises the following steps: (1) evaluating key engineering parameters of shale gas; (2) determining a fracturing fluid system and a proppant; (3) optimizing fracture parameters and fracturing construction parameters; (4) determining the position of a fracturing section shower hole and perforating parameters; (5) carrying out acid pretreatment; (6) carrying out low viscosity quick water low-displacement fracture heightcontrolling fracturing; (7) carrying out ultra low density proppant screen-out fracturing; (8) carrying out multi-scale fracture fracturing packing; and (9) according to a hole volume of each fracturing section, carrying out over-displacing operation according to 110-120%. The volume fracturing method of deep shale gas multi-scale proppant packing, disclosed by the invention, has the advantages that the net pressure is effectively increased by combining processes of optimizing acid treatment to reduce a fracture pressure, carrying out low viscosity quick water low-displacement injection fracture height controlling, screening out in a mixed ultra low density proppant fracture and so on, and through full-process small particle size proppant injection construction, the filling degree of the deep shale gas fracture system of small and micro fracture development is enhanced. Therefore, the effective volume of the fracture is further increased, and the long-time fracture flow conductivity isfurther improved.

The invention provides a method for forming multiple fractures by forced planar diverting of a fracture opening being temporarily plugged. The method includes: allowing temporary plugging diverting material fluid to a position near the fracture opening in a reservoir so as to form a bridge plug and force the fracture to divert, forming multiple fractures, activating micro-fractures of the reservoir with active liquid or acid liquid, and forming a multi-fracture mesh. The method according to the technical scheme has the advantages that artificial fractures in unconventional oil-gas reservoirs, such as low-permeability and ultralow-permeability oil-gas reservoirs, tight oil reservoirs and shale oil-gas reservoirs, are forced to divert in the plane, forming multiple artificial fractures having guiding ability, chances to connect reservoir bodies are increased, drainage area is enlarged, cleaning diverting material is of degradability and can fully degrade after construction, all the fractures can be utilized, and yield increase is more obvious.

The invention discloses a refracturing method by naturally selecting dessert temporary blocking size for a horizontal well. The refracturing method comprises the steps that a well with certain geologic reserves is selected, and geological dessert areas of the whole horizontal well which needs to be subjected to refracturing are ruled again; a new rock mechanics crack initiation order is predicted;the dessert area with rich accumulation of oil and gas and with the best physical property is found, and a first fracture is pressed to be open; the first fracture is blocked through a temporary blocking agent, fracturing liquid is pumped into continuously, the pressure rises, the dessert area of the secondary grade is selected, and a second fracture is pressed to be open; multiple fractures of athird fracture, a fourth fracture and the like are sequentially pressed to be open, and fracturing of the multiple fractures with naturally selected desserts in a segment is realized; and meanwhile,the powder-like high-strength water-soluble temporary block agents are put into the fractures so as to form temporary blocking on the end of the main fracture, the net pressure in the fracture is increased, the micro-fracture which cannot crack originally is pressed to be open, or the new branch fracture is formed, and a larger transformation size is obtained. According to the refracturing method,the defect that a sleeve is deformed, and consequently, a downhole tool cannot be tripped into is effectively overcome, and recovering and increasing of the productivity of the horizontal well are facilitated.

The invention discloses a fracturing method for deep shale gas through a V-shaped pressure curve. The fracturing method comprises the steps of (1) key reservoir parameter evaluation, (2) optimizationof fracture parameters and fracturing construction parameters, (3) perforation position determination and perforation operation, (4) acid pretreatment, (5) variable-displacement and low-viscosity slick water joint forming construction, (6) powder pottery construction for adding different sand liquid ratios into low-viscosity slick water, (7) medium-particle-size proppant construction for adding different sand liquid ratios into medium-viscosity slick water, (8) high-viscosity gel and large-particle-size carrying proppant construction, and (9) displacing operation. According to the fracturing method, complexity of fracturing fractures of the deep shale gas is improved, the filling ratios of systems with different scales of fractures such as near wells, far wells, main fractures and micro-fractures are increased, the effective stimulation volume of the deep shale gas is increased, and the yield increasing and stabilizing effects after pressure are improved.

A method of processing a glass substrate including texturing the glass substrate to form a textured surface that includes a plurality of micro fractures extending from the textured surface into the substrate. And, thereafter, chemically etching the textured surface of the glass substrate to a depth sufficient to remove the micro fractures. The glass substrate can then be chemically strengthened after the etching step.

A nuclear magnetic resonance quantitative analysis method for a rock micro-crack damage variable is provided; firstly, a sample is processed, the sample is soaked in distilled water, then nuclear magnetic resonance detection is carried out, CPMG pulse sequence detection is carried out on the sample, a spin echo train attenuated signal is obtained, the spin echo train attenuated signal is subjected to inversion, and a T2 spectrum distribution diagram and a spectral area value are obtained; a corresponding relation of the relaxation time T2 and the pore size r is analyzed; according to a fact that the spectral peak area is proportional to the micro-fracture pore number, a rock damage variable formula characterized by the nuclear magnetic resonance transverse relaxation time T2 spectra is established, and the quantitative analysis method is provided for identification of damage of rock materials.

The invention is directed to a process for making a dielectric ceramic film capacitor and the ceramic dielectric laminated capacitor formed therefrom, the dielectric ceramic film capacitors having increased dielectric breakdown strength. The invention increases breakdown strength by embedding a conductive oxide layer between electrode layers within the dielectric layer of the capacitors. The conductive oxide layer redistributes and dissipates charge, thus mitigating charge concentration and micro fractures formed within the dielectric by electric fields.

The invention discloses a gas extraction well location method based on an overlying rock fracture shell. The gas extraction well location method based on the overlying rock fracture shell is characterized by comprising the step of drilling tilting holes with large diameters in multiple areas of a gob overlying rock from a gas tail lane (6) directly. The multiple areas of the gob overlying rock comprise a low post fracture shell (1), a middle post fracture shell (2) and a high post fracture shell (3) from bottom to top, wherein the low post fracture shell (1) is a gob fracture vertical destroying development zone, the high post fracture shell (3) is a gob separation layer fracture and micro fracture development zone, and the middle post fracture shell (2) is located between the high post fracture shell and the low post fracture shell. The construction of extracting and drilling is carried out directly by using the existing gas tail lane, and extraction drilling holes are respectively arranged in the multiple areas of the overlying rock. Not only can gas with high concentration be effectively extracted, but also a seepage field on a gob return air side zone is interfered. Extraction efficiency is high, the processes of digging, drilling and drainage lane are reduced, the link of process engineering is simplified, and cost is lowered.

The invention provides a deformation and stability monitoring system for a side slope and the whole process of the construction period and the primary water storage period of a dam. The monitoring system comprises a plurality of micro vibration sensors, distributed type micro electro mechanical system (MEMS) deformation observation instruments and a data collecting and processing subsystem. The multiple micro vibration sensors are distributed on the side slope and used for sensing micro-fracture signals of a rock mass of the side slope. The distributed type MEMS deformation observation instruments are distributed on the side slope and used for sensing deformation of different depths of the side slope. The distributed type MEMS deformation observation instruments are distributed on the dam and used for sensing deformation of the whole process of the construction period and the primary water storage period of a dam body. Each MEMS deformation observation instrument is formed by connecting a wireless transmission module and a plurality of MEMS acceleration sensors in series. The data collecting and processing subsystem is used for collecting the micro-fracture signals of the rock mass of the side slope and deformation data of the side slope and the dam body, wherein the micro-fracture signals are sensed through the micro vibration sensors, and the deformation data are sensed through the MEMS acceleration sensors. The deformation and stability situations of the side slope and the dam body are analyzed and monitored according to the collected data. The overall deformation and stability situations of the near-dam-area of the high concrete dam can be continuously monitored in the whole construction process and the primary water storage whole process through the deformation and stability monitoring system.

The invention belongs to the technical field of road surface coating materials, and in particular relates to a salt-storage epoxy/polyurethane composite coating material for a highway and a preparation method thereof. The technical scheme is as follows: components A, B and C are included, wherein the component A comprises waterborne epoxy resin emulsion; the component B comprises a waterborne epoxy resin curing agent, waterborne polyurethane, emulsified asphalt, rutile titanium dioxide, a defoaming agent, a flatting agent and industrial water; the component C comprises an ice melting agent and industrial water. The preparation method comprises the steps of uniformly mixing the components A, B and C according to a ratio, coating or spraying to a road surface at normal temperature and curing, so as to obtain the salt-storage epoxy/polyurethane composite coating material for the highway. The salt-storage epoxy/polyurethane composite coating material for the highway has a good active ice and snow melting function, the film-formed coating material has excellent abrasive resistance, water tolerance and high/low temperature resistance, and can perform fog seal protection and beautification on old road surfaces and micro-fractures, prevent rain water infiltration, prolong the service of the road surface and increase driving comfort, and the like.

A method for texturing a surface of a substrate comprising creating micro-fractures in the surface of the substrate to be textured, and etching the surface of the substrate to be textured to open the micro-fractures.

The present invention relates to the field of drilling fluids, and discloses a strong plugging drilling fluid suitable for shale gas wells and a preparation method of the drilling fluid. The drilling fluid contains water, bentonite, a tackifier, a flow pattern regulator, a filtrate reducer, a plugging agent, and a weighting agent, wherein, based on 100 parts by weight of water, the content of the bentonite is 1-10 parts by weight, the content of the tackifier is 5-15 parts by weight, the content of the flow pattern regulator is 4-13 parts by weight, the content of the filtrate reducer is 4-13 parts by weight, the content of the plugging agent is 20-55 parts by weight, and the content of the weighting agent is 10-60 parts by weight; the drilling fluid provided in the present invention employs modified nano-silica as a plugging agent to improve dispersity and particle size distribution in the drilling fluid system. Therefore, the drilling fluid is especially suitable for well drilling in shale formations with developed micro-fractures (micro-fissures) and micro-pores, low porosity and low permeability (10⁻³-10⁻⁷ md), and prominent capillary effect.

A manufacturing method of a shell includes the following steps that a metal base body is provided, micro-fracture cutting is conducted on the metal base body so that the metal base body can be cut into at least one metal piece and at least one body part, two first side surfaces which are parallel are formed on each metal piece, and second side surfaces opposite to the metal pieces are formed on the body parts as well; surface processing is conducted on the metal pieces and the body parts where micro-fracture cutting is conducted, and a plurality of holes are formed in the first side surfaces and the second side surfaces; and the body parts and the metal pieces are placed in a mold in a butt joint manner, the width of gaps between the body parts, between the body parts and the adjacent metal pieces and between the adjacent metal pieces is 0.1-0.3 mm, non-conductor parts are contained in the gaps and are partly embedded in the holes, and therefore the body parts and the metal pieces are connected through the non-conductor parts. The invention further provides the shell manufactured through the manufacturing method, and an electronic device with the shell.

The invention discloses a method for fracturing a high-angle naturally-fractured oil reservoir by using a permanent plugging agent; the method comprises: drifting a well with a drift size gauge tool, and washing mechanical impurities in a shaft; running pressure test; perforating a segment to be fractured in the shaft; tripping in a fracturing string to carry out fracturing; pumping a prepad fluid; squeezing large-particle-size temporary plugging agents of different ratios in multiple rounds to a prepad fluid phase in a slug manner so that high-angle natural fractures are plugged primarily; pumping a sand-carrying fluid; filling the high-angle natural micro fractures by using a small-particle plugging agent in spiral slug sand-adding manner so that effective propagation of the fractures is ensured; finally, opening the well for gushing, acquiring production, and completing the well. The method provided herein has the advantages that upper and lower high-angle natural factures of a reservoir are effectively plugged, fracture breakthrough during fracturing is prevented, fracture height is controlled, long-fracture modification is achieved, full modification of the reservoir is guaranteed, a fracturing technical mode suitable for high-angle naturally-fractured reservoirs is formed, and initial yield is increased by 20% and above.

The invention discloses a method for distinguishing the position of a rockburst risk on a deep buried tunnel section. The method comprises the following steps: A, performing numerical simulation analysis according to the shape of a section, engineering geology, conditions of initial ground stress and an excavation method before tunnel excavation, to be specific, a, performing indoor rock mechanics experiments and parametric inversion; b, confirming a three-dimensional initial ground stress field; c, constructing a geometrical model for three-dimensional numerical calculation according to stratigraphic distribution, geologic construction and the size of the tunnel section; d, implementing numerical calculation and analysis of a tunnel excavation process for the geometrical model; e, analyzing the distributed situation of the local energy release rate on the tunnel section; B, monitoring slight shock in a real-time mode in the tunnel excavation process, to be specific, 1, mounting a sensor at the rear part of a tunnel face; 2, collecting slight shock signals in the process of the micro fracture of rock mass to invert the occurrence position of the micro fracture of surrounding rocks; 3, analyzing the projection distribution of micro fracture events on the tunnel section; C, performing comprehensive evaluation on the distinguished occurrence positions of the rockburst risk. Through the adoption of the method, the occurrence of rockburst disasters is reduced or avoided, and the construction safety and the construction progress are ensured.

The invention provides a method for controlling fracturing of multiple fractures of an oil and gas field with a natural micro-fracture-developed reservoir stratum. By adopting the early high-sand-ratio powdery ceramsite proppant slug technique, a few ceramsites are injected by a high-sand-ratio proppant slug at a prepad fluid stage to plug natural fractures of the reservoir stratum, and therefore, the generation of the multiple fractures is effectively controlled and reduced, and the construction success rate and the post-fracturing effective rate are improved. With the high-sand-ratio proppant slug entering the stratum, all cracks of which the crack width is smaller are plugged. New multiple fractures during the extension process of a major fracture are plugged by a low-sand-ratio proppant slug at middle and later periods. After the high-sand-ratio proppant slug is added, as proved by fitting construction net pressure, the natural micro-fractures are largely plugged, and the pressure of the reservoir stratum slightly rises. As the multiple fractures are effectively controlled, the construction pressure is stable, and the goal that the multiple fractures are controlled to form the major fracture is achieved. Proved by a test in Yao Ying Tai oil field of Jilin province, the fracturing method for controlling multiple fractures of the oil and gas field with the natural micro-fracture-developed reservoir stratum has the advantages that the implementation is simple, the application is convenient, and the multiple fractures are effectively controlled, and is suitable for being applied to the reform of the natural micro-fracture-developed reservoir stratum.

The invention provides a fractured reservoir horizontal well injection-production asynchronous exploitation method. The method comprises the steps that 1, area selecting and well selecting are conducted, specifically, a reservoir stratum with developed natural micro-fractures is selected, fractured water breakthrough in the multi-section fractured horizontal well production process is achieved through waterflooding extraction, and when the average increasing amount of the water content every day is larger than or equal to 1.5%, remaining oil within a horizontal well controlled area is used for an injection-production asynchronous oil extraction horizontal well; 2, the oil extraction horizontal well is closed, 80-100 cubic meters of water is injected into a water injection well, and the oil extraction horizontal well is closed; 3, the water injection well is closed, then, the oil extraction horizontal well is opened for oil extraction, the injected water entering matrix rock blocks is preserved, and the equal amount of crude oil replacing the injected water enters a fracture system, flows into a shaft and is extracted; and 4, the next round of water injection is started, the step 2 and the step 3 are repeated, and injection-exploitation asynchronous operation is conducted for 8-10 periods. According to the fractured reservoir horizontal well injection-exploitation asynchronous exploitation method, on the basis of the seam-net type fractures, the contact area of the injected water and the fractures is enlarged, the oil-water replacement amount is further increased, the reservoir overall imbibitions yield-increasing effect is improved, and accordingly the purposes of decreasing the water content of the fractured water breakthrough horizontal well, increasing the liquid amount and the oil amount, and supplementing the stratum energy are achieved.

The invention discloses a tubular column for evenly injecting steam in an SAGD (Steam Assisted Gravity Drainage) horizontal well and a process. The tubular column comprises a vacuum heat insulation pipe, a thermal compensation extension pipe and a steam injection pipe, the vacuum heat insulation pipe is connected with the thermal compensation extension pipe through the steam injection pipe, a backflushing packer is arranged at the front part of the steam injection pipe; one or more fracture-steam injection units are arranged at the middle part of the steam injection pipe, the fracture-steam injection unit comprises a fracture valve, a steam injection valve and a centering guide, the fracture-steam injection units are packed through a heat sensitive packer, and a backflushing valve is arranged at the tail end of the steam injection pipe. By applying the process of micro-fracturing evenly, backflushing the well, packing in a segmenting way, and injecting the steam in a segmenting way onthe steam injection horizontal well, the purpose of rapidly evenly injecting steam into a thickened oil reservoir stratum is fulfilled. The tubular column is suitable for the SAGD steam injection horizontal well with strong stratum heterogeneity and poor heat and mass transfer capacity.

The invention provides self-powered multifunctional piezoelectric intelligent aggregates for an asphalt pavement, and belongs to the field of health monitoring of asphalt pavements. According to the self-powered multifunctional piezoelectric intelligent aggregates for the asphalt pavement in the invention, the modulus after epoxy resin is cured is approximately equal to the asphalt pavement; the piezoelectric intelligent aggregates encapsulated by the epoxy resin 6200A have a certain strength and durability; the piezoelectric intelligent aggregates have good coupling performance with the pavement, and can be used in the asphalt pavement for a long time; furthermore, the piezoelectric intelligent aggregates do not influence the pavement performance of the pavement; micro-fracture damage monitoring can be carried out in the asphalt pavement; furthermore, an encapsulation container is prepared from the epoxy resin 6200A, a curing agent and quartz powder together; the encapsulation container has high surface hardness and resists corrosion, aging and hot and cold impact; due to encapsulation protection, influence of factors, such as the temperature and the humidity, on a signal measurement result can be weakened or eliminated; interference of an external environment on driving signals and sensing signals can be effectively overcome; therefore, a measurement result is relatively accurate; and simultaneously, the self-powered multifunctional piezoelectric intelligent aggregates in the invention are low cost, simple in structure and steady in performance, and can be widely used inthe asphalt pavement.

Methods comprising: introducing a micro-proppant treatment fluid into a formation at a rate and pressure sufficient to create or enhance at least one fracture in a first treatment interval, wherein the micro-proppant treatment fluid comprises a first aqueous base fluid, micro-proppant particulates, and a first aqueous-based surface modification agent (“ASMA”); placing the micro-proppant particulates into the at least one fracture; introducing a surface modification treatment fluid into the subterranean formation, wherein the surface modification treatment fluid comprises a second aqueous base fluid and a second ASMA; coating at least a portion of a face of the at least one fracture with the second ASMA; introducing a macro-proppant treatment fluid into the subterranean formation, wherein the macro-proppant treatment fluid comprises a third base fluid and macro-proppant particulates; and placing the macro-proppant particulates into the at least one fracture.

The invention discloses a stope micro-earthquake continuous monitoring intelligent early-warning instrument, which is characterized in that a micro-earthquake sensor sensing and collecting device is arranged at a stope access or in an adjacent drift roadway so as to monitor stope rock mass micro-fracture signals and collect the micro-earthquake time, the micro-earthquake frequency, the micro-earthquake energy, the micro-earthquake magnitude and the micro-earthquake location; a micro-earthquake signal processing system analyzes the collected data so as to carry out judgment on the stability state of stope rock mass and carry out recognition on a potential rock mass collapse hidden danger location of the stope; and an early-warning device carries out sound-light signal early warning on the stability of the stope rock mass. The stope micro-earthquake continuous monitoring intelligent early-warning instrument can perform monitoring on the stope rock mass stability, and carries out early warning on potential safety hazards such as roof collapse, wall caving and rock burst in a stope personnel operation area. Workers are enabled to check and process rock mass collapse hidden dangers in the stope personnel operating area timely, and safety accidents such as roof collapse, wall caving and rock burst can be effectively controlled and reduced.