100 results about "Triaxial compression" patented technology

The invention relates to a method, a device and equipment for analyzing in-situ formation fracture porosity of mixed rock. Comprising the steps of obtaining original data of a plurality of layers in a target block; taking out a first rock core sample from each layer of the target block, and performing experimental analysis on the first rock core sample of each layer to determine a target layer; taking out a second core sample from the target horizon, and performing a triaxial compression test on the second core sample to obtain a stress index; according to the original data and the stress index, the stratum fracture porosity of the target layer is calculated, the stratum fracture porosity is used for guiding workers to evaluate the real underground in-situ fracture porosity of the reservoir, and therefore an oil and gas reservoir exploitation plan of the target layer is made. The stratum fracture porosity calculated by the method represents the fracture porosity of the target horizon in the target block and represents in-situ characteristics in the stratum, so that the accuracy of reservoir evaluation is improved. A worker can formulate an oil and gas reservoir exploitation plan according to the formation fracture porosity, and the oil and gas reservoir yield is improved.

The invention discloses a deep shale brittleness evaluation method based on energy evolution, electronic equipment and a medium. The method comprises the following steps: collecting basic parameters of a target stratum, and determining key parameters; carrying out a total stress-strain triaxial compression experiment according to the key parameters to obtain a total stress-strain curve of the rock core; dividing the total stress-strain curve, and respectively calculating the strain energy density related to the rock; and calculating the mineral brittleness index of the rock according to the key parameters and the strain energy density. According to the method, mineral components and energy evolution in the whole rock deformation-damage process are considered at the same time, and the brittleness characteristics of deep shale can be better reflected.

The invention relates to a plugging layer three-hole three-seepage well circumference effective stress calculation method and system, and the method comprises the steps: collecting a reservoir rock core, and obtaining rock matrix mechanical characteristic parameters through triaxial compression; the method comprises the following steps: collecting a reservoir core and on-site drilling fluid, firstly, obtaining physical and chemical parameters of interaction between a rock aperture and the drilling fluid through a pressure transfer experiment, then, testing physical and chemical parameters of interaction between a rock fracture fluid and the drilling fluid, and finally, testing physical and chemical parameters of an effective plugging layer formed by the drilling fluid and rock; establishing a three-hole three-permeability model considering a rock matrix field control equation, a rock fracture field control equation and a plugging layer field control equation; and calculating and considering the effective stress around the three-hole three-seepage well of the plugging layer. According to the method, the influence of fluid seepage and solute diffusion rules in the drilling fluid plugging layer on the well circumference stress distribution rule can be effectively analyzed, the formation collapse pressure and fracture pressure can be further calculated in combination with the strength criterion, and the drilling fluid density design is guided.

The invention belongs to the technical field of rock mechanical property research, and discloses a rock elastic-plastic damage constitutive model establishment method considering freeze-thaw strength and compaction effect, and the method comprises the following steps: proposing a concept of freeze-thaw strength to comprehensively reflect the freeze-thaw damage degrees of rock at different freeze-thaw temperatures and durations; performing a freeze-thaw test and a triaxial compression test on the rock test piece, recording test data in the triaxial compression test process, drawing a stress-strain curve based on the test data, and constructing a yield function and a hardening rule of the rock test piece based on the strength characteristic parameters of the freeze-thaw rock; establishing a rock elastic-plastic damage constitutive equation considering the freeze-thaw effect and the compaction effect; and determining a parameter expression of the rock elastic-plastic damage constitutive model based on an elastic-plastic theory in combination with freeze-thaw rock triaxial compression test data. According to the technical scheme, the compaction stage and the volume deformation of the frozen-thawed rock can be reflected, and the method has the advantages of being wide in application range and high in prediction precision.

The present invention provides a method for designing a dynamic and static universal loading path for true triaxial mechanical tests. The loading path design is carried out in the stress space. The principal stress space is sliced into a set of stress meridian plane spaces, realizing the conversion from a three-dimensional design environment to a two-dimensional design environment. Based on the above two-dimensional design environment, the dynamic and static universal loading paths under three different loading modes of triaxial compression, triaxial tension, and tension-compression compound are designed respectively. The design results in the two-dimensional design environment are converted into three-dimensional final design results. It can make the results of dynamic and static true triaxial mechanical tests comparable. The distribution of the dynamic and static true triaxial mechanical test loading paths in the stress space can be set as needed.

The invention relates to the technical field of oil and gas well wall stability and fracturing yield increase development, in particular to a deep high-temperature rock statistical damage constitutive model construction method which comprises the following steps: performing mineral component and microstructure analysis on a deep rock core by adopting XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope) technologies, and performing quantitative statistics on mineral content to obtain a deep high-temperature rock statistical damage constitutive model. The method comprises the following steps: acquiring rock brittleness and plasticity characteristic basic data, performing a triaxial compression test by adopting a high-temperature triaxial compressor, and establishing a constitutive model capable of reflecting deep high-temperature rock damage; according to the mechanical characteristics of the deteriorated rock due to temperature rise, the provided model is verified to accurately simulate stress-strain curves of a sample in each stage of a single axis and a conventional three axis under different temperatures and confining pressures, the rationality of indexes is verified, and the deep high-temperature rock statistical damage constitutive model is obtained. The method solves the problem that in the prior art, a statistical damage constitutive model capable of accurately reflecting stress-strain characteristics of the deep high-temperature rock at each stage of a single axis and a conventional three axis under different temperatures and confining pressures is lacked.

The invention discloses surrounding rock seepage experiment equipment based on triaxial compression and a detection method of the surrounding rock seepage experiment equipment. The surrounding rock seepage experiment equipment comprises a base, an arch-shaped rack fixed to the base, a triaxial pressure assembly, an axial loading assembly, a seepage assembly and a data acquisition assembly, wherein the triaxial pressure assembly, the axial loading assembly, the seepage assembly and the data acquisition assembly are installed on the base; the triaxial pressure assembly comprises a confining pressure self-adaptive homogenizing device, and the confining pressure self-adaptive homogenizing device utilizes a lifting driving assembly to regulate and control the position of an outer cylinder in real time and automatically compensate the surface pressure gradient of a rock sample, so that uniform transfer of confining pressure is ensured, and localized deformation inducements are inhibited fundamentally; for dynamic deformation position data disjunction caused by monitoring capability deficiency, the multi-dimensional permeability monitoring and collecting assembly is driven by the driving assembly to move around a rock sample, a localized deformation area is locked in real time, seepage state parameters (such as permeability and flow velocity) of the position are synchronously captured, and it is ensured that data strictly correspond to the deformation process.

The invention discloses a method for calibrating finite-discrete element input parameters of a water-containing rock, which comprises the following steps of: respectively carrying out a uniaxial tensile test, a uniaxial compression test and a triaxial compression test on a dry rock sample and rock samples with different water contents; obtaining an evolution equation of the tensile strength along with the moisture content, an evolution equation of the elastic modulus and the uniaxial compressive strength along with the moisture content, and an evolution equation of the cohesive force and the internal friction angle along with the moisture content; carrying out a lateral constraint water absorption swelling test on the dry rock to obtain a vertical expansion evolution curve; on the basis of the obtained results, the fracture energy, the humidity expansion coefficient and the humidity diffusion coefficient in the finite-discrete element method are calibrated; on the basis of the calibration parameters, finite-discrete element uniaxial and triaxial compression numerical simulation of the rock samples with different water contents is carried out, and simulation results are obtained; and when the error between the test result and the simulation result is within a preset threshold value, obtaining a final parameter calibration result. The invention provides a simple, accurate and efficient parameter calibration means for water-rock interaction mechanism research.

The invention discloses a method for constructing a rock dynamic damage constitutive relation under the freeze-thaw-load effect, and belongs to the technical field of rock damage, and the method comprises the following steps: determining a dynamic damage evolution equation based on evolution characteristics of a rock dynamic damage rate under the freeze-thaw-load effect and a macromechanical parameter change rule; the method comprises the following steps: abstracting a rock under the action of freeze-thaw-load into four parts, namely freeze-thaw damage, load-bearing damage, coupling damage and non-damage, bearing effective stress by the non-damage part, bearing residual stress by the damage part, and establishing a rock constitutive model based on a dynamic damage rate; freeze-thaw cycle and conventional triaxial compression tests of the red sandstone are carried out, and the rationality of the model is verified through test results. According to the method, the model is established in a mode of combining theoretical derivation and test verification, the goodness of fit between the obtained theoretical curve and the test curve is high, the mechanical behavior of rock freeze-thaw load damage can be well reflected, and theoretical guidance can be provided for design and construction of cold region engineering.

The embodiment of the invention relates to the technical field of oil exploration and development, in particular to a shale reservoir compressibility calculation method, device and equipment, and the method comprises the steps: obtaining a rock sample of a shale reservoir on a construction site; calculating the bedding development index of the rock sample; the bedding development index represents the bedding structure development degree of the rock sample; performing a triaxial compression experiment on the rock sample under the simulated shale reservoir environment to obtain a brittleness index of the rock sample; the brittleness index represents the strain degree of brittle fracture of the rock sample; scanning the rock sample after the triaxial compression experiment to obtain a fractal dimension index of the rock sample; the fractal dimension index represents the space structure complexity of the three-dimensional crack in the rock sample; and calculating the compressibility of the shale reservoir according to the bedding development index, the brittleness index and the fractal dimension index. According to the embodiment of the invention, the compressibility of the shale reservoir can be accurately and quickly evaluated on the construction site by integrating the bedding structure development degree, the fracture strain degree and the space structure complexity of the rock sample.

The invention relates to a method for establishing a rock creep failure time prediction model under a conventional triaxial compression condition. The method comprises the following steps: performing conventional triaxial compression tests on a target rock under n groups of different creep stresses under preset confining pressure to obtain n creep curves; for any creep curve, acquiring creep failure time and constant-speed creep rate corresponding to the creep curve, so as to obtain a plurality of to-be-fitted points; linear fitting is carried out on the multiple to-be-fitted points to obtain a fitting curve, fitting parameters of the fitting curve are obtained, and the fitting parameters comprise the slope and the intercept; and obtaining a rock creep failure time prediction model of the target rock under the conventional triaxial compression condition according to the fitting parameters. When the model is used, only the target rock needs to be tested subsequently, and the damage time can be predicted according to the model when the creep rate is monitored, so that constructors can conveniently take protective measures in advance.

The invention belongs to the field of rock mechanics, and particularly discloses a shale multi-scale mechanical property characterization method which comprises the following steps: acquiring mechanical parameters of shale under a macroscale through a triaxial compression experiment; obtaining mechanical parameters of the shale in a mesoscale through a micron indentation experiment; generating a shale surface modulus distribution diagram through a modulus imaging experiment, and combining with an SEM-EDS experiment to determine the composition and elastic modulus of microscopic minerals of the shale; a Mori-Tanaka method is used for carrying out scale upgrading on the micromechanical properties of the shale, the equivalent mechanical parameters of the shale under the macroscopic scale are obtained by integrating the volume fractions, the elastic parameters and the porosity of all phases of microminerals in the shale, and the micromechanical properties and macroscopic response of the microminerals are effectively bridged. According to the method, the anisotropy of the shale in the dimension is disclosed from multiple scales, and the mechanical behaviors and the internal relation of the shale in the macroscopic scale and the microscopic scale are comprehensively disclosed.

The invention provides a method for predicting rock permeability in an elastic-viscoelastic-viscoplastic deformation stage, and belongs to the technical field of rock permeability prediction. In order to effectively predict permeability evolution trends of rocks in different deformation stages and overcome the defects in the prior art, the invention provides a method for predicting permeability of rocks in an elastic-viscoelastic-viscoplastic deformation stage. Obtaining triaxial compressive strength data of the rock under different confining pressure level conditions; setting a creep stress level, and performing a rock sample creep-seepage experiment to obtain axial deformation data of the rock sample and gas pressure data of a gas inlet end and a gas outlet end of the sample; the axial load of the rock sample is unloaded to a hydrostatic pressure state, the confining pressure is kept unchanged, and a seepage experiment in a pressure relief deformation recovery stage is carried out; the method is applied to calculation and prediction of the rock permeability.

The invention discloses a carbonate rock pore retention mechanism simulation method under an ultra-deep heat-fluid-solid coupling effect, and relates to the technical field of rock physics. The method comprises the following steps: preparing a carbonate rock sample, obtaining a CT scanning slice image of the carbonate rock sample, extracting three-dimensional pore information, preparing a plunger sample in a laboratory, carrying out a quasi-triaxial experiment, calibrating mesoscopic parameters by using a laboratory test result, constructing a carbonate rock model, and arranging a measuring ball in the carbonate rock model, the method comprises the following steps: dynamically monitoring the change of porosity and pore pressure, determining a strength reduction function of carbonate rock through a laboratory experiment, applying a true triaxial compression servo environment in which a temperature field and a stress field cooperatively change to a carbonate rock model, and performing true triaxial experiment numerical simulation by using the carbonate rock model. The internal pore condition of the carbonate rock in each evolution stage is obtained, the pore retention mechanism of the carbonate rock under the ultra-deep heat-fluid-solid coupling effect is determined, and technical support is provided for research of carbonate rock reservoirs.

The invention belongs to the technical field of testing and sampling, and particularly discloses a semi-closed tube type static and dynamic triaxial undisturbed sample cutting ring soil sampler. Two ends of an upper joint of the soil sampler are respectively provided with interfaces connected with a drill rod and fixed with a waste soil pipe, and the bottom end of a pipe boot is provided with a cutting edge I; an outer soil sampling pipe of the soil sampling pipe is of a tubular structure formed by buckling two semi-closed pipes, external thread sections are arranged at the two ends of the outer soil sampling pipe respectively, the two ends of the outer soil sampling pipe are in threaded connection with a waste soil pipe and a pipe shoe through the external thread sections, a cutting ring support is of a double-pipe structure formed by buckling two omega-shaped semi-closed pipes, the cross section of the cutting ring support is in a transverse 8 shape, and the cutting ring support can be embedded into the outer soil sampling pipe and is provided with a fixing groove. The cutting ring is of a tubular structure formed by buckling two semi-closed tubes and can be embedded into the fixing groove. The cutting ring support of a semi-closed double-pipe structure is arranged in the soil sampling pipe, and two cutting rings can be fixed through the fixing grooves in the cutting ring support respectively, so that four tailing undisturbed samples can be sampled at a time to meet the requirements of a group of samples for a triaxial compression test, and the device has the characteristics of simple structure, easiness in disassembly and assembly and small disturbance.

A continuous logging method and device is provide, where the method includes obtaining drilling fragment samples and full-diameter core samples, and screening out target rock cuttings from the drilling fragment samples; performing a micro-indentation experiment on the target rock cuttings to obtain a static parameter thereof; performing a triaxial compression experiment on the full-diameter core samples to obtain a dynamic parameter and a static parameter thereof; determining a first correspondence between the static parameter of the target rock cuttings and the dynamic parameter of the full-diameter core samples; determining a second correspondence between logging data and the static parameter of the target rock cuttings based on the first correspondence; and drawing a formation mechanical property profile based on the second correspondence. The method solves the problem of conventional methods which cannot draw a continuous and complete profile of the mechanical property of the whole well section.

An infrared and acoustic emission monitoring rock true triaxial rapid unloading confining pressure test system and method. Mainly include: rigid pressure loading system, air pressure control system, gas confining pressure chamber, infrared observation system. The vertical loading system provides Z direction load; the lateral loading system provides Y direction load; the external gas source provides gas pressure, enters the gas pressure chamber through the floor gas pipeline, provides X direction load; the gas pressure chamber X direction is provided with front and rear infrared observation windows, both are CaF2 glass materials, can erect infrared thermal imager to realize infrared observation; the loading plate can be built-in acoustic emission probe through the detachable structure. The present application uses the pressure head and the pressure plate to provide the pressure in Y direction and Z direction through special design, uses the gas to supply the pressure in X direction, can realize the X direction rapid unloading, and solves the problem that the infrared visualization is difficult to realize in the true triaxial compression test process. Through the detachable design of the loading plate, the acoustic emission probe can be built-in.

The present invention discloses a method for generating initial stress of coal-bearing strata and tunnels in PFC3D, including: obtaining the ground stress parameters of the research block location and the macroscopic basic physical and mechanical parameters corresponding to the coal body and the rock mass, and calibrating the parameters through the PFC3D triaxial compression numerical simulation technology; preliminarily establishing the PFC3D coal-bearing strata numerical model according to the microscopic mechanical parameters and stratum size corresponding to the coal body and the rock mass, and preloading through the wall servo; establishing the FLAC3D model area boundary of the PFC3D coal-bearing stratum numerical model, and generating the coupling surface of the PFC‑FLAC calculation, setting the constitutive model and material parameters corresponding to the coal body and the rock mass at the FLAC3D model area boundary; assigning ground stress to the coal body and the rock mass at the FLAC3D model area boundary and setting the boundary conditions of the model, performing equilibrium calculation on the entire numerical model to generate the initial stress of the coal-bearing strata, and generating a three-dimensional model of the coal tunnel according to the tunnel size excavation calculation. The present invention realizes the accurate generation of the initial stress of the coal-bearing strata and the tunnel.

The present invention relates to the technical field of sample preparation for testing, and discloses a sample preparation device for triaxial testing of granular materials and a method for using the same, that is, on the one hand, when the petals of the molding mold are molded together, by making the bottom of the molding mold sleeve on the top periphery of the mold base and pressing the bottom of the sample wrapping film, the structural stability of the mold during sample preparation can be improved; on the other hand, before sample preparation, the internal ventilation structure of the mold petals can be used to form a negative pressure so that the middle part of the sample wrapping film is stretched and tightly attached to the inner wall surface of the molding mold, which is convenient for laying the sample wrapping film, thereby facilitating the sample preparation efficiency and qualified rate of non-sticky cylindrical samples. In addition, since the triaxial compression test can be conveniently performed on the molded non-sticky cylindrical sample when the petals are opened, compared with the existing vacuum sample preparation method and the freezing sample preparation method, time and steps can be saved, and the efficiency of sample preparation and testing can be greatly improved.

The invention relates to a set of mold for preparing a specific-density to-be-tested sample in a triaxial compression test, and belongs to the field of geotechnical engineering sample devices.The mold comprises a pressing and clamping assembly, a forming assembly is arranged in the pressing and clamping assembly, and a pressure applying assembly is slidably connected to the pressing and clamping assembly; the bottom end of the pressure applying assembly extends into the forming assembly to apply pressure to a sample located in the forming assembly, a functional ring is arranged at the end of the pressing and clamping assembly, and the functional ring abuts against the end of the pressing and clamping assembly. According to the invention, the operation process is simplified, the efficiency and safety of taking out the sample are improved, and the preparation work of the sample can be completed more efficiently and accurately, so that the quality and efficiency of a triaxial compression test are improved.

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 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.

This invention discloses a surrounding rock seepage experimental device and its detection method based on triaxial compression, comprising: a base, an arched frame fixed on the base, and a triaxial pressure component, an axial loading component, a seepage component, and a data acquisition component mounted on the base; the triaxial pressure component includes a confining pressure adaptive homogenization device. This invention utilizes a lifting drive component to adjust the position of the outer cylinder in real time through the confining pressure adaptive homogenization device, automatically compensating for the pressure gradient on the rock sample surface, ensuring uniform transmission of confining pressure, and fundamentally suppressing localized deformation causes; addressing the disconnect in dynamic deformation location data caused by insufficient monitoring capabilities, the multidimensional permeability monitoring and acquisition component moves around the rock sample under the drive of the drive component, locking the localized deformation area in real time, and simultaneously capturing the seepage state parameters (such as permeability and flow velocity) at that location, ensuring strict correspondence between the data and the deformation process.

The invention discloses a method for constructing a biaxial compression strength prediction model of a double-hole model sample, which comprises the following steps of: correcting a Mohr-Coulomb strength criterion by combining intermediate principal stress to obtain a Mohr-Coulomb strength formula corresponding to the triaxial compression strength of a complete rock; introducing a hole reduction coefficient, and obtaining a reduction model corresponding to the hole influence; a Mohr-Coulomb strength formula corresponding to the triaxial compression strength of the complete rock is reduced, and a triaxial compression strength prediction model of the double-hole model sample is obtained; and obtaining a biaxial compression strength prediction model of the double-hole model sample. By introducing the hole reduction coefficient, the coupling influence of coexistence of the two holes and geometric configuration of the two holes on the macroscopic strength of the rock mass is clearly quantified, the technical defect that an existing rock mass strength prediction model cannot accurately reflect the strength weakening effect caused by interaction of the two holes is overcome, and compared with a complex full-three-dimensional numerical simulation method, the method has the advantages that the method is easy to implement. The model calculation process is simpler, more convenient and more efficient.

The invention relates to a triaxial rock brittleness evaluation method based on a cohesive polymerization degradation-friction strengthening model. The triaxial rock brittleness evaluation method comprises the following steps: obtaining a load-time curve and a uniaxial stress-strain curve of a Brazilian splitting experiment and a stress-strain curve of a triaxial compression experiment; determining a uniaxial brittleness index based on a Mohr-Coulomb shear strength curve and a CWFS model according to a load-time curve and a uniaxial stress-strain curve; determining a confining pressure influence brittleness coefficient according to a triaxial stress-strain curve under different confining pressures based on the Moire circle, the cohesive force and the friction angle change trend under the triaxial stress state; and determining a triaxial brittleness index Btri by using the uniaxial brittleness index Bu and the confining pressure influence brittleness coefficient Bp. The core parameters adopted by the brittleness index are cohesive force and internal friction angle and can be directly obtained through petroleum engineering conventional logging data inversion, the field application threshold is remarkably reduced, and the limitation that the traditional brittleness index depends on special experimental data is broken through.

The invention relates to a continuous and discontinuous numerical simulation method for researching cryptocrystalline basalt size effect evaluation, which can comprehensively consider heterogeneity of a rock internal structure and mechanical response of samples with different sizes so as to reveal the influence of the size effect on rock mechanical characteristics. By establishing a numerical model based on an actual rock microstructure and applying a continuous and discontinuous numerical simulation technology, the mechanical behaviors of cryptocrystalline basalt of different sizes under a uniaxial or triaxial compression condition can be accurately simulated; the obtained rock mass mechanical parameters under the REV size can be used as input parameters of large-scale numerical simulation of engineering rock mass, and a scientific basis is provided for rock engineering design and construction.

The utility model discloses a triaxial compression working condition loading clamp for a thermal shock test, which comprises a lower end plate and an upper end plate, the lower end plate and the upper end plate are correspondingly provided with a plurality of mounting through holes, the plurality of mounting through holes are uniformly distributed, a bolt piece is arranged in each mounting through hole, the lower end plate is connected with the upper end plate through the bolt pieces, and the lower end plate is connected with the upper end plate through the bolt pieces. A plurality of test piece mounting grooves are formed between the adjacent mounting through holes; a large strip-shaped groove and a small strip-shaped groove are formed in the middle of the lower end plate, and the middle of the large strip-shaped groove and the middle of the small strip-shaped groove are communicated in a crossed mode. The lower end plate and the upper end plate of the triaxial compression working condition loading clamp are provided with corresponding test piece mounting grooves, so that loading of a plurality of test pieces in the axial direction can be realized; the lower end plate and the upper end plate are provided with corresponding large strip-shaped grooves and small strip-shaped grooves, so that external pressure or internal pressure loading of a plurality of test pieces can be realized; therefore, the test piece can also realize a loading test under a triaxial compression working condition at a thermal shock temperature.

The invention discloses a reservoir sand production risk prediction method under gas storage injection-production circulation. The reservoir sand production risk prediction method sequentially comprises the following steps that S1, a sandstone reservoir is machined into a standard cylindrical rock core sample; s2, selecting a first group of rock core samples, carrying out a uniaxial compression test, and calculating uniaxial compressive strength and uniaxial compression elasticity modulus; s3, selecting a second group of rock core samples, carrying out a triaxial compression test, and calculating triaxial compressive strength; s4, selecting a third group of rock core samples, performing a triaxial cyclic loading and unloading test, and drawing a cyclic loading and unloading stress-strain curve; s5, preliminarily evaluating the sand production of the sandstone under cyclic loading and unloading, and calculating damage factors in the cyclic loading and unloading process of the rock core; and S6, predicting the reservoir sand production risk through the compressive strength after cyclic damage. The reservoir sand production risk prediction method under the gas storage injection-production circulation provides a scientific basis for guiding gas storage injection-production operation in actual production, is expected to effectively reduce negative effects of a sand production phenomenon on production, and improves production efficiency and operation safety.

The invention discloses a rock dynamic and static tension and compression multi-field coupling test method, and relates to the technical field of rock dynamic load, static load, tension and compression, shearing, rheology, temperature, seepage, chemistry, ultrasonic wave, acoustic emission, resistivity and other multi-field coupling tests. The sample is of a dumbbell-shaped structure with upper and lower end diameters larger than the middle diameter; the method comprises a triaxial axial tensile test, a triaxial compression test, a triaxial dynamic impact test, a dynamic and static triaxial multi-field coupling test at different temperatures and a true triaxial shear seepage coupling test. In the triaxial tensile test process, the end part of the test sample does not need to be glued, the test sample adopts a dumbbell-shaped test sample shape design, the axial tensile force is provided by using a confining pressure loading system and adopting confining pressure, and the axial tensile test of the rock under different confining pressure conditions can be realized.

This application discloses a rapid method for determining the macroscopic strength parameters of layered rock masses. For layered rock masses without discontinuous joints or fractures, the method includes the following steps: S1. Conducting conventional uniaxial triaxial compression tests on matrix rock blocks to obtain the stress-strain curves of the matrix rock blocks, and fitting the peak strength and residual strength of the matrix rock blocks under different confining pressures to obtain the strength parameters of the matrix rock blocks; S2. Conducting shear tests on bedding samples to obtain the stress-strain curves of the bedding surfaces, and fitting the peak strength and residual strength of the bedding surfaces under different normal stresses to obtain the strength parameters of the bedding surfaces; S3. Taking the average of the peak strength of the matrix rock blocks and the peak strength of the bedding surfaces, as well as the average of the residual strength of the matrix rock blocks and the residual strength of the bedding surfaces, to obtain the macroscopic equivalent strength parameters of the layered rock mass without discontinuous joints or fractures.