78 results about "Rock failure" patented technology

The invention discloses a deep well rock mass instability failure time accurate forecasting and early warning system, and relates to the technical field of deep well rock mass failure early warning, and the deep well rock mass instability failure time accurate forecasting and early warning system comprises the following steps: collecting a plurality of deep well rock samples to carry out a uniaxial compression experiment, and collecting acoustic emission signals in real time based on an acoustic emission sensor to obtain original acoustic emission signal data; carrying out self-adaptive preprocessing, and carrying out data classification and integration to obtain rock sample acoustic emission parameter data; constructing an original damage forecasting model, and performing model training and verification optimization based on the rock sample acoustic emission parameter data to obtain a rock damage forecasting model; collecting an acoustic emission signal of the deep well rock mass, and predicting the instability failure time of the deep well rock mass in real time based on the rock failure forecasting model; the method is used for solving the problems that when an existing deep well rock mass damage early warning technology carries out early warning on rock mass instability damage through acoustic emission monitoring, single or few characteristic parameters are manually processed and analyzed, and the early warning reliability and timeliness are not high.

The invention relates to the technical field of computers, and discloses a rock creep model construction method and device and a rock failure mode determination method. The method comprises the steps of obtaining a data set; samples in the data set comprise input data and output data, the input data comprise creep load holding time, sample rock stress data, initial macroscopic damage data, initial microscopic damage data, long-term strength and a creep starting threshold value, and the output data is a strain true value; fitting the initial rock creep model by using the data set to obtain a final rock creep model; wherein the initial rock creep model comprises at least one of a damaged elastomer strain item, a damaged viscoelastomer strain item and a damaged viscoplastic body strain item; each strain item comprises a macro-micro nonlinear coupling damage item, and the macro-micro nonlinear coupling damage item is generated based on the initial micro damage data and the initial macro damage data. The model constructed by the method can truly reflect the nonlinear mechanical response of the rock mass under the combined action of the multi-scale initial defects.

The invention provides a reservoir mechanical integrity evaluation method under high-frequency injection and production. The evaluation method comprises the steps that S1, rock sample compressive strength and mechanical property parameters of a reservoir under multiple confining pressures are determined; s2, determining the upper limit and the lower limit of the reservoir pressure of the energy storage reservoir in the injection-production process; s3, obtaining the critical fatigue strength of the reservoir rock sample under a plurality of confining pressures within the designed age limit; s4, determining a deviating stress-average stress plane according to the compressive strength and the critical fatigue strength of the rock sample under the plurality of confining pressures, and dividing rock failure zones on the deviating stress-average stress plane; and S5, establishing a geomechanical model to predict the stress level of the reservoir, and judging the safety of the reservoir during the cyclic injection-production period from the perspective of mechanical integrity. Safe, efficient, economical and lasting operation of the energy storage warehouse is guaranteed, and a feasible method is provided for expanding the application range of compressed air energy storage.

The invention provides a fractured rock damage prediction method and system, and belongs to the field of rock mechanics and engineering monitoring. The problem that a prediction result obtained by an existing fractured rock damage prediction method is not accurate is solved. According to the technical scheme, the method comprises the following steps: synchronously obtaining a DIC image sequence and an acoustic emission signal in a loading process of a to-be-measured fractured rock, carrying out data processing to generate a gray variance evolution curve and an acoustic emission b value evolution curve, and extracting a gray variance surge point on the gray variance evolution curve and a b value surge point on the acoustic emission b value evolution curve; performing time sequence comparison on the gray variance sharp increase point and the b value sudden drop point on a time axis, and when the gray variance sharp increase point and the b value sudden drop point meet a preset consistency condition on the time axis, judging the corresponding gray variance sharp increase point or b value sudden drop point as a damage critical point of the fractured rock; the method is applied to rock failure prediction.

The invention relates to the technical field of thermocycling damage treatment, in particular to a granular rock thermocycling damage prediction method, which comprises the following steps: establishing a particle-based numerical model by using discrete element software; setting initial temperature and confining pressure of the rock sample, and constructing a heating, balancing and cooling experiment process; setting different preset temperature values and temperature rising and cooling step lengths; elastic modulus damage and crack number development are obtained; thermal damage is calculated through elastic modulus damage and crack number development, the relation between rock volume thermal strain and rock heating-cooling damage under different confining pressures is obtained, and a damage prediction model of rocks under different confining pressures under the cold and heat cycle condition is constructed. Aiming at the rock damage problem caused by rock heating expansion and cooling shrinkage, the thermal damage and volume thermal strain model considering heating and cooling is constructed, and the universality of the model is high.

This invention provides a method and device for short-term early warning of rock failure based on acoustic emission clustering analysis, relating to the fields of rock mechanics and geotechnical engineering. The method includes: acquiring acoustic emission characteristic parameters during rock deformation and failure; performing clustering analysis on the acoustic emission characteristic parameters using the K-means++ algorithm to obtain cluster labels corresponding to the acoustic emission characteristic parameters; calculating the importance scores of the acoustic emission characteristic parameters based on the cluster labels using the random forest algorithm; constructing an early warning index set based on the acoustic emission characteristic parameters; constructing an initial CNN-LSTM model; establishing a sample dataset of conventional and precursor signals of rock failure based on the early warning index set; training the initial CNN-LSTM model using the sample dataset to obtain a trained CNN-LSTM model; acquiring real-time acoustic emission signals; and inputting the real-time acoustic emission signals into the trained CNN-LSTM model to provide early warning by identifying the acoustic emission signal category. This invention can provide early warning for complex rock failure processes.

The invention relates to a rock mechanics testing method and system based on artificial intelligence, and the method comprises the steps: carrying out the three-dimensional scanning of a rock sample, and obtaining three-dimensional model data; sending into a convolutional neural network to analyze the surface characteristics of the rock sample, and obtaining the initial state parameters of the rock sample; according to the initial state parameters, a rock mechanics test loading scheme is formulated through an adaptive optimization algorithm, and a test execution instruction is obtained; applying a preset load to the rock sample according to the test execution instruction, and synchronously acquiring mechanical response data and a deformation image sequence; according to the deformation image sequence, constructing a full displacement field and a strain field of the rock sample, and obtaining global deformation characteristics; and based on the global deformation characteristics and the mechanical response data, identifying damage behavior parameters of the rock sample through a time sequence characteristic extraction algorithm, and obtaining a damage type. Intellectualization, data closed loop and self-evolution of the whole rock mechanics test process are achieved, and the test precision and the reliability of rock damage prediction are improved.

This invention belongs to the fields of rock mechanics, signal processing, and deep learning. It provides an intelligent method, device, equipment, and medium for identifying rock fracture types. The method includes: acquiring acoustic emission signal data, loading stress-strain data, and rock image / video of the rock sample; extracting multimodal features from the acoustic emission signal data and loading stress-strain data; performing principal component analysis on the multimodal features to obtain a dimensionality-reduced feature matrix; labeling training data using a rock failure event time-series correlation method to obtain crack type labels; training and detecting using a gated recurrent unit network based on the dimensionality-reduced feature matrix and crack type labels to obtain a shear crack probability sequence, and then calculating the tension-shear ratio within a time step; and generating time stamps in the rock image / video based on the tension-shear ratio. This invention achieves accurate and rapid identification of rock fracture types and real-time monitoring of the dynamic evolution of fractures.

The invention discloses a rock material tension-shear failure simulation method and equipment based on a dynamic dual-phase field model. The method comprises the following steps: establishing a stress tensor physical model corresponding to a rock material constitutive relationship; respectively introducing a tension phase field and a shear phase field, and establishing a dynamic double-phase field model corresponding to the rock tension-shear failure physical process; deducing an energy functional of the dynamic double-phase field model; establishing a crack surface local coordinate system, and judging a crack contact state according to a frictional contact phase field theory; switching a stress tensor decomposition mode according to the contact state, and calculating a phase field evolution driving force; rock material tension-shear failure simulation based on the dynamic two-phase field model is achieved, and rock fracture form evolution data are output and used for evaluating rock slope stability.

The application discloses a rock residual strength determination method based on an energy drop ratio parameter and belongs to the technical field of geological engineering. According to a rock stress-strain curve obtained through a rock triaxial test, the energy of each component in a failure process is calculated according to the rock stress-strain curve characteristics, and based on the energy evolution law in the rock failure process, an energy drop ratio parameter is proposed to quantitatively represent the strength drop. A residual strength determination method considering the whole rock failure process is proposed through the energy drop ratio parameter. The application comprehensively considers the influence of the pre-peak stage and the post-peak stage on the residual strength, proposes a rock residual strength determination method suitable for different post-peak drop trends, and calculates the stability of the broken rock mass through the residual strength, which has an important guiding role for the excavation, design and stability evaluation of the rock mass engineering.

The invention discloses a three-dimensional failure criterion construction method considering bedding and three-dimensional stress and intermediate principal stress effect degradation, and the method comprises the steps: S1, obtaining rock strength data through true triaxial static tests under different bedding dip angles, direction angles and intermediate principal stress; s2, constructing a transverse isotropic strength characteristic function based on the spatial relationship between the bedding structure and the loading direction; s3, introducing an intermediate principal stress degradation parameter, and establishing a rock failure criterion considering three-dimensional stress and intermediate principal stress effect degradation; s4, constructing a three-dimensional failure criterion considering bedding space and three-dimensional stress and intermediate principal stress effect degradation; s5, determining model parameters by fitting static test data, and drawing a strength evolution curve; and S6, based on the three-dimensional failure criterion parameters, drawing a stratified rock strength prediction curve. According to the method, quantitative characterization of true three-dimensional stress, middle principal stress degradation and bedding three-dimensional space effect coupling of the strength of the layered rock is achieved for the first time.

The invention discloses a test method and system of an indoor model for ultra-large-span cavern excavation support and a medium, and relates to the technical field of geotechnical engineering physical model tests. Through the counter-force frame and the three-dimensional gradient active loading system, a real non-uniform three-dimensional crustal stress field is precisely restored. By means of a numerical control mechanical arm carrying a head-replaceable end effector, a finish-milling cutting head and a negative pressure suction system, extra disturbance of excavation to surrounding rock is reduced. Excavation and support triggering conditions are preset to control actuator tool switching, and excavation-support time sequence linkage is achieved. Through cooperative acquisition and analysis of a pre-embedded sensor, monitoring equipment around a model box and a multi-source data acquisition cabinet, full-dimensional data is obtained, and the finally constructed four-dimensional surrounding rock failure evolution comprehensive map completely presents the whole process from microscopic crack initiation to macroscopic instability. And a high-fidelity test basis is provided for risk pre-judgment and design optimization of a super-large-span cavern project.

The invention discloses a chamber excavation surrounding rock failure area simulation method and related equipment, and relates to the field of geotechnical engineering stability evaluation.The method comprises the steps that an underground chamber excavation process is simulated through an underground chamber initial model without setting support measures, a plastic zone range is obtained, and principal stress information of a corresponding unit of a failure area is extracted; calculating the damage degree of the surrounding rock based on the surrounding rock stress state; performing zoning operation on the damage area according to the surrounding rock damage degree to obtain refined zoning information; on the basis of a triaxial compression test, rock mechanical parameters related to the residual strength of the surrounding rock under different damage degrees are obtained; assigning values to different partitions with different damage degrees according to the rock mechanical parameters related to the residual strength; and excavation numerical simulation is conducted again to obtain a new plastic zone range and main stress distribution, and final partition assignment and refined simulation are completed. According to the method, the authenticity, engineering adaptability and reliability of numerical simulation are improved, and the method has clear technical progress and engineering practical value.

The invention provides a surrounding rock staged failure semi-analytical solution method and system suitable for tunnel water gushing, and belongs to the technical field of tunnel engineering. The method comprises the steps that according to test data under different water contents, all surrounding rock mechanical parameters are fitted, and a surrounding rock mechanical parameter fitting equation considering the water contents is obtained; the three-dimensional arch effect in the tunnel excavation process is considered, and the surrounding rock damage process caused by tunnel excavation is divided into two stages, namely the first stage and the second stage; in the first stage, the surrounding rock failure mode is that the first stress of the excavation effect is redistributed; in the second stage, the surrounding rock failure mode is that stress is redistributed again under the combined action of the excavation effect and the water weakening effect; and for the second stage, establishing a circular tunnel calculation model considering the water weakening effect, and performing mechanical calculation on the surrounding rock failure process by adopting a semi-analytical method. Through two-stage division, the excavation effect and the water weakening effect are considered, and the progressive failure characteristics of the surrounding rock under the water gushing condition are described more accurately.

The embodiment of the present application provides a kind of unconventional oil and gas reservoir brittleness evaluation method, device, equipment, medium and product, it is related to unconventional oil and gas reservoir exploration and development technical field.Aiming at the problem that the brittleness evaluation of current unconventional oil and gas reservoir is not well matched with reservoir reconstruction effect, a brittleness evaluation method according to reservoir rock failure energy and deformation behavior is proposed to realize the quick and accurate evaluation of reservoir rock brittleness, and provide theoretical guidance for the selection of fracturing target reservoir and fracturing scheme design.The present application uses the basic principle that the greater the rock brittleness, the smaller the energy consumed by the rock under uniaxial / triaxial compression and the smaller the rock deformation, combines the uniaxial / triaxial compression failure energy of rock with the deformation of rock at the time of failure, obtains the compression failure energy and deformation parameters of rock using the stress-strain curve of rock, and evaluates the brittleness of reservoir rock by the deformation size under unit energy when rock fails.

The invention discloses a rock residual strength determination method based on energy drop ratio parameters, and belongs to the technical field of geological engineering. According to a rock stress-strain curve obtained by a rock triaxial test, energy of each component in the damage process is calculated according to characteristics of the rock stress-strain curve, and based on an energy evolution rule in the rock damage process, an energy drop ratio parameter is proposed to quantitatively characterize strength drop; a residual strength determination method considering the whole rock damage process is provided through an energy drop ratio parameter; according to the method, the influence of the pre-peak stage and the post-peak stage on the residual strength is comprehensively considered, the rock residual strength determination method suitable for different post-peak descending trends is provided, the stability of the fractured rock mass is calculated through the residual strength, and the method has an important guiding effect on excavation, design and stability evaluation of rock mass engineering.

The application relates to the technical field of geotechnical engineering, and in particular to a rock failure precursor identification method and device, a storage medium and computer equipment. The method comprises the following steps: acquiring a multimodal acoustic signal of a rock under the superposition of different types of loads; dividing the multimodal acoustic signal according to a preset time window to obtain a multimodal acoustic signal segment; performing time-frequency analysis on the multimodal acoustic signal segment to construct a time-frequency matrix of the multimodal acoustic signal segment; performing singular value decomposition on the time-frequency matrix to obtain a singular value sequence of the time-frequency matrix; calculating the information entropy of the singular value sequence to obtain the time-frequency singular entropy of the multimodal acoustic signal segment corresponding to the singular value sequence; constructing a time-frequency singular entropy sequence of the multimodal acoustic signal according to the time-frequency singular entropy of the multimodal acoustic signal segment; and identifying a rock failure precursor based on the time-frequency singular entropy sequence of the multimodal acoustic signal. The application avoids false positives and false negatives in rock failure precursor identification, and makes early warning more reliable.

The application discloses a kind of shallow-buried tunnel surrounding rock failure simulation device, belong to tunnel construction technical field, including transparent and top opening test box, detachably connected with tunnel model between the front and rear sidewall of the test box, surrounding rock for covering tunnel model is arranged in the test box, base is fixed in the tunnel model, a plurality of support rods connected with the inner wall of tunnel model are arranged on the base, monitoring instrument is arranged at the end of the support rod, vibration generator is further arranged in the tunnel model;Building model is arranged above the surrounding rock, and pile foundation model is arranged in the surrounding rock in the lower end of building model;Sensor for detecting the settlement of building model is arranged on the test box;The purpose of the application is to solve the problem that the existing shallow-buried tunnel surrounding rock failure simulation device does not consider the influence of tunnel surrounding rock failure on building (structure).

The invention relates to a rock failure stage identification method based on multi-channel acoustic emission feature fusion. The method comprises the following steps: collecting acoustic emission signals of a plurality of acoustic emission sensors arranged on a rock to be detected; counting the acoustic emission signals according to time windows with preset duration, and extracting acoustic emission characteristic parameters corresponding to each time window; and inputting the acoustic emission characteristic parameters corresponding to the acoustic emission sensors in the same time window into the trained rock failure stage identification model to obtain the failure stage of the rock to be detected in the current time window. Real-time and high-precision identification of a rock damage stage is realized through multi-channel acoustic emission signal fusion and a deep learning model; multiple sensors are used for collecting signals, the model automatically extracts high-dimensional features and enhances key information by means of an attention mechanism, and the recognition accuracy and robustness are remarkably improved; compared with a traditional method, the method can output judgment in real time, and provides effective support for engineering safety monitoring and early warning.

The application provides a coal rock damage real-time prediction method and device based on acoustic emission signal analysis, which comprises the following steps: in the case of performing coal rock damage test, obtaining statistical information of multiple acoustic emission signals; the statistical information comprises waveform data and the number of acoustic emission events; determining the fracture type of each acoustic emission signal according to the waveform data, and determining the b value and b absolute change rate of the value of each acoustic emission signal according to the waveform data and the number of acoustic emission events; determining the shear fracture proportion corresponding to the multiple acoustic emission signals according to the fracture type, and analyzing the statistical feature evolution information of the waveform data to obtain a target statistical feature; determining the warning threshold according to the b value, b absolute change rate of the value, the shear fracture proportion and the target statistical feature, and performing coal rock damage real-time prediction through the warning threshold. The method and device provided by the application can realize warning only by using the signals before the current time, and improve the accuracy and real-time performance of coal rock damage real-time prediction.

The invention discloses an experimental device, a prediction device and a method for rock water inrush damage based on combination of acoustic emission and resistivity, belongs to the field of rock damage monitoring, and aims to improve the accuracy of water inrush damage monitoring. The device is characterized in that the device comprises a shell, a stress loading plate, an electrode plate, a pressurization system, a hydraulic fracturing system, a resistivity monitoring system, an acoustic emission monitoring system and a processing system, the processing system builds the relation between fracturing pressure and the resistivity of a rock sample in the time dimension according to the fracturing pressure and the resistivity of the rock sample, and the resistivity of the rock sample is measured according to the relation. Determining the variation trend of the resistivity of the rock sample in the water inrush damage process caused by the fracturing pressure according to the relationship, obtaining the variation trend of the resistivity of the rock sample in the time range from the time when the fracturing pressure is applied to the rock sample to the time when the fracturing fluid overflows from the rock sample, and calculating the position information of the water inrush point according to the acoustic emission signal.

The invention discloses a quantitative characterization method for evolution characteristics of a micro-pore structure in a rock failure process, and belongs to the technical field of rock pore structure research. On the basis that an existing characterization method cannot accurately describe pore evolution in rock and a damage process under a loaded condition, a three-dimensional model of a rock sample is constructed by applying a CT image interactive threshold segmentation and three-dimensional model reconstruction method on the basis of a uniaxial compression in-situ CT real-time scanning test of mudstone and sandstone; according to the method, a three-dimensional pore model and a pore network bat model of a digital rock core are established, a plurality of parameters such as a porosity evolution coefficient, a porosity overall evolution coefficient, a pore fractal dimension, a throat fractal dimension, a pore network structure coefficient and a damage evolution factor are defined, and the evolution characteristics and the distribution form of a pore structure in the rock damage process are quantitatively represented. The fine identification and visual quantitative characterization of the rock internal pore evolution in the uniaxial compression process are realized, and a new method is provided for quantitatively evaluating the damage evolution of the rock.

A deep engineering dynamic disturbance hard rock true triaxial CT real-time scanning experiment device belongs to the technical field of rock mechanics experiments and comprises a base, a true triaxial loading mechanism and a CT real-time scanning mechanism. According to the invention, the whole-process CT real-time scanning of the dynamic disturbance true triaxial experiment can be realized, the information of the crack development process in the rock at different loading moments can be obtained, and the problems that the rock fracture in the traditional true triaxial experiment cannot be directly observed, the error of other monitoring means is large, and the result is inaccurate are solved; the true triaxial experiment of the stress release and dynamic disturbance coupling effect can be carried out, the working condition of a deep engineering hydraulic fracturing technology for preventing dynamic disasters is simulated, and the evolution process of cracks in rocks at different moments is obtained through CT real-time scanning, so that the evolution process of the cracks in the rocks is subjected to accurate three-dimensional reconstruction; the three-direction dynamic disturbance true triaxial experiment, the long-time fatigue true triaxial experiment and the hydraulic fracturing dynamic disturbance coupling true triaxial experiment can be carried out, and CT real-time scanning and three-dimensional reconstruction are achieved in the experiment process.

The invention relates to a method for simulating mining-induced fault surrounding rock fracture and water inrush evolution, which comprises the following steps of: establishing a water-conducting fault surrounding rock fracture numerical model based on an FDEM according to a simulation early-stage preparation condition; setting a coal seam mining scheme; analyzing fracture evolution of the surrounding rock of the fault by simulating a coal mining process on the basis of the numerical model of fracture of the surrounding rock of the water-conducting fault; a dominant water inrush channel is selected, and a CFD-based water diversion fault surrounding rock fracture water inrush seepage numerical model is established; and analyzing seepage element evolution based on the water diversion fault surrounding rock fracture water inrush seepage numerical simulation result. By constructing the simulation method for inducing fracture and water inrush evolution of the fault surrounding rock by mining, the coal mining process can be comprehensively and accurately simulated, fracture and water inrush evolution of the fault surrounding rock can be analyzed, and a powerful means is provided for research on fault water inrush.

This application provides a method for finely characterizing the fractured area of ​​the floor strata in a mining face, relating to the field of coal seam floor characterization technology. The method includes: collecting the original microseismic event signals and environmental correlation parameters corresponding to each microseismic event in the fractured area of ​​the mining face floor strata; performing feature extraction to obtain a microseismic event feature matrix corresponding to each microseismic event; inputting a microseismic event classification model to obtain the rupture correlation confidence score of the microseismic event; if the source type of any microseismic event is rupture type, and the corresponding rupture correlation confidence score is greater than a preset rupture correlation confidence score threshold, then the fractured area of ​​the mining face floor strata is characterized based on this microseismic event. This application achieves fine characterization of the fractured area of ​​the mining face floor strata, providing a reliable basis for engineering safety control.

This invention provides a method and system for predicting pile end resistance based on a mudstone damage constitutive model, relating to the field of geotechnical engineering. Addressing the difficulty in quantitatively analyzing and calculating the bearing capacity of dynamically driven piles in mudstone foundations and the damage characteristics of the surrounding mudstone, this invention establishes a statistical damage constitutive model for mudstone based on the stress state-determined damage variable D and its association with rock failure criteria. Model parameters are determined according to triaxial test results, and the relationship between the critical damage variable and confining pressure is established. The damage characteristics of the mudstone surrounding the dynamically driven pile are analyzed, thereby calculating the pile end resistance and meeting the need for quantitative analysis of pile end damage characteristics.

The invention discloses a surrounding rock failure mode recognition method and system and a computer storage medium, and relates to the technical field of model driving information processing and digital twinning, and the method comprises the steps: constructing and dynamically updating a digital twinning model of tunnel surrounding rock through fusing LiDAR point cloud data and GPR geological radar data; performing simulation prediction in combination with real-time construction parameters, and analyzing a surrounding rock failure trend; dividing a key area and a non-key area by using a digital twin model identification result, and setting a differential sampling frequency and a monitoring strategy according to regional importance; when the model predicts that the damage mode tends to a dangerous state, a construction parameter adjusting scheme is automatically output, differential monitoring and risk early warning can be achieved while the safety of the scheme can be simulated and evaluated in combination with the construction parameters, the dangerous state damage mode can be effectively prevented from occurring in the construction process, and tunnel construction safety and efficiency are improved.

The invention discloses a three-dimensional discrete fracture network modeling and simulation method based on fracture statistical characteristics, and relates to the technical field of water conservancy and hydropower engineering rock soil. According to the method, geometric and distribution characteristics of rock mass fractures are collected on site, and a random statistical model containing parameter relevance is constructed; generating a three-dimensional DFN model based on a random statistical model, and performing intersection processing, invalid fracture elimination and boundary correction optimization; the three-dimensional DFN model is embedded into a numerical platform, a fracture-rock system is constructed, Mohr-Coulomb constitutive parameters are given, crustal stress inversion, excavation supporting and operation load simulation are completed in sequence, and mechanical response data are obtained; and finally analyzing surrounding rock failure characteristics and optimizing a support scheme. The problem that a traditional model is difficult to represent a discontinuous structure and local instability is solved, the prediction precision is improved, the method is adaptive to various complex fractured rock mass projects, and reliable support is provided for stability evaluation and support design.

This article relates to the field of oil industry drilling engineering technology, and in particular to a shale gas formation drilling risk assessment method, device, and equipment. The method includes establishing a rock mechanics parameter calculation model and a geostress parameter calculation model for the target formation; selecting a rock failure criterion based on the rock mechanics parameter calculation model, the geostress parameter calculation model, the degree of collapse of the wellbore already drilled in the target formation, and the density of the drilling fluid already drilled; determining the construction risk level corresponding to the degree of collapse of the wellbore already drilled based on the construction conditions of the already drilled well; and determining the drilling risk corresponding to the density of the drilling fluid to be drilled in the target formation based on the construction risk level and the rock failure criterion. Through the embodiments of this article, a quantitative assessment of the construction risk of the drilling fluid density of the well to be drilled during on-site construction of a shale gas formation is achieved, and at the same time, it can accurately guide on-site construction to select a reasonable drilling fluid density, ensuring safe drilling underground.

The utility model relates to the technical field of geological experiment testing, and discloses a rock point load tester, which comprises a seat frame part, a top seat part and baffle connecting plates, a bracket is arranged on a top rod of a jack, the baffle connecting plates are detachably inserted and arranged on two sides of the bracket, and when test detection is carried out, a rock is placed between the bracket and a sensor end; the jack is used for jacking up the bracket to apply a vertical concentrated load until the rock is damaged, the damaged rock can be blocked by the blocking and connecting plate to prevent splashing from hurting an operator, meanwhile, the damaged rock can be borne by the blocking and connecting plate, and the rock can be effectively prevented from hitting equipment and a test board.