49 results about "Pore scale" patented technology

The invention relates to a method and a device for determining the flow characteristic of CO2 in a porous medium and the distribution rule of CH4 in a pore space. The method comprises the following steps: (1) pretreating a sample; (2) system connection and air tightness inspection; (3) vacuumizing the system; (4) temperature control; (5) CH4 saturation and pressure stabilization; (6) displacement experiment and data acquisition; (7) monitoring outlet gas; and (8) data processing. The problem that in existing CO2 geological sequestration and enhanced gas production research, due to the fact that in-situ visualization of the pore size cannot be achieved, a microscopic displacement mechanism is unclear is solved, and the method aims at providing scientific basis and technical support for efficient exploitation of natural gas and effective geological sequestration of CO2.

The invention discloses a method and a system for improving carbon dioxide mineralization and storage efficiency. The method comprises the following steps: building a microfluidic experiment platform integrated with an online CO2 mineralization and storage monitoring system; on a microfluidic experimental platform, simulating a formation temperature and pressure condition to carry out a CO2 mineralization corrosion experiment to obtain pore scale reaction kinetic parameters and a pore structure evolution rule; macromineralization efficiency data are obtained through an indoor physical simulation mineralization reaction experiment of the core scale; a CCM-GEM reaction flow numerical model is constructed; determining a Pareto optimal solution set by using a CMG-GEM reaction flow numerical model; and based on the pore scale reaction kinetic parameters, the pore structure evolution law, the macromineralization efficiency data and the Pareto optimal solution set, determining a CO2 mineralization storage efficiency improvement path of the target rock sample. According to the method, global sensitivity analysis and automatic optimization of multiple parameters are rapidly completed, the research and development period is shortened, the economic cost and the time cost are reduced, and the research efficiency is improved.

The invention discloses a method and a device for determining water blocking damage degrees of different pore sizes of a rock core. Comprising the following steps: acquiring physical property data of a target rock core and simulated formation water; vacuumizing, pressurizing and saturating the target rock core to obtain a saturated water state rock core, and obtaining a first transverse relaxation spectrum and a first longitudinal and transverse relaxation correlation spectrum through nuclear magnetic resonance; performing displacement treatment on the rock core to obtain a water-bound state rock core, and obtaining a second transverse relaxation spectrum and a second longitudinal and transverse relaxation correlation spectrum; determining a pore size range, and establishing a water blocking damage identification chart to define a characteristic interval between bound water and saturated water; carrying out difference operation to obtain a difference spectrum matrix, extracting pore space areas of bound water and saturated water in the matrix, and calculating an area ratio; and determining the water blocking damage degrees of different pore sizes by combining the porosity, the permeability and the ratio. According to the method, the pore scale can be accurately divided, the damage of each scale can be quantified, the development efficiency can be optimized, and a reliable basis is provided for formulating a reservoir unblocking scheme.

The invention discloses a lignin-based porous adsorption material as well as a preparation method and application thereof, and belongs to the technical field of adsorption material preparation. The preparation method comprises the following steps: grinding and sieving a pore-foaming agent to obtain a pretreated pore-foaming agent; the preparation method comprises the following steps: uniformly mixing lignosulfonate, a pretreatment pore-foaming agent, a cross-linking agent, a catalyst and water, and carrying out a cross-linking reaction to obtain a cross-linked body; and cleaning, dehydrating and drying the cross-linked body to obtain the product. The invention further discloses the lignin-based porous adsorption material prepared by the method and application of the lignin-based porous adsorption material. Compared with a traditional chemical crosslinking curing adsorption material, the lignin-based porous adsorption material has higher specific surface area and functional group utilization rate; the used pore-foaming agent has good water solubility, does not participate in the reaction in the crosslinking process and can be removed to form pores after crosslinking, the porosity and the pore size of the product can be regulated and controlled by adjusting the dosage and the particle size of the pore-foaming agent, and the application prospect is wide.

The application discloses a digital core permeability prediction method and device, equipment and a storage medium, and relates to the oil and gas field, which comprises the following steps: acquiring voxel data of a target digital core, and performing feature extraction on the voxel data by using a target pore network extraction algorithm to obtain corresponding graph structure data; obtaining target hidden features corresponding to the graph structure data by using a target encoder network, updating the target hidden features by using a target graph neural network to obtain updated hidden features, and obtaining micro physical quantities corresponding to the voxel data at a pore scale by using a target decoder network based on the updated hidden features; determining a target pressure field corresponding to the target digital core based on the micro physical quantities, determining total flow data corresponding to the target digital core based on the target pressure field and the micro physical quantities, and determining a target permeability corresponding to the target digital core based on the total flow data. The application realizes deep coupling of digital core permeability micro physical field prediction and macroscopic physical property derivation.

The application of prediction method for diffusion behavior of underground hydrogen in pore scale of water-containing clay mineral belongs to the technical field of underground hydrogen energy storage and unconventional gas migration prediction, and the key point is to fill water molecules and salt ions into the pores according to the target water saturation and salinity; the initial model of the water-containing clay mineral pores is pre-equilibrated by the molecular dynamics method; hydrogen molecules are filled under the given temperature and pressure conditions by the grand canonical Monte Carlo method, and the hydrogen pressure is corrected by the SRK-EOS state equation; the hydrogen diffusion simulation is carried out by the molecular dynamics method with temperature and fugacity as input parameters, the mean square displacement of hydrogen in the pores is calculated, and the self-diffusion coefficient is obtained; the application can quantitatively characterize the diffusion rate change rule of hydrogen in the clay pores under different water film thickness, salinity and temperature and pressure conditions, and reveal the diffusion inflection point, diffusion inhibition stage and migration restriction mechanism caused by the water film or water bridge structure.

The application discloses a kind of cross-scale multi-component deep shale gas mobility evaluation method, it is related to oil and gas resource evaluation technical field.The application utilizes molecular simulation software to construct multi-component deep shale gas pore occurrence model, utilizes its simulation to obtain the density variation curve of each component of shale gas fluid under different pressure conditions, divides adsorption zone and free zone, then determines the shale gas density calculation function of adsorption zone and free zone, establishes shale gas mobility evaluation formula under molecular scale and is applied to pore scale, in combination with the pore network model extracted from the core of deep shale reservoir according to field acquisition, obtains the size distribution of its throat and pore, respectively calculates adsorption zone volume and free zone volume, utilizes shale gas mobility evaluation formula to evaluate the shale gas operation of deep shale reservoir, realizes accurate evaluation to multi-component deep shale gas mobility on molecular level, provides technical support for the efficient formulation of deep shale gas development plan.

The method for measuring the distribution and evolution characteristics of gas-water-oil three-phase contact angle in oil reservoir porous media belongs to the technical field of oil and gas exploitation and wettability measurement. The method is based on micro-nano CT imaging technology, through three-phase fluid seepage experiment, micro-nano CT scanning, CT image processing and analysis, and finally the statistical distribution characteristics of gas-water-oil three-phase contact angle in oil reservoir porous media under different flow states are obtained. By real-time acquisition of the interface state in the seepage process, in-situ, real and efficient measurement of three-phase contact angle is realized, which can reveal the seepage-induced wettability transition and local wettability reversal phenomenon. The fine division of water-wet, oil-wet and gas-wet pore space in oil reservoir porous media can be realized; the measurement results can provide reliable wettability data for pore-scale multiphase seepage simulation. Since the measurement results are the statistical characteristics of a large number of local contact angles, the authenticity and statistical accuracy of the contact angle measurement are significantly improved.

The invention provides a four-phase hydrate-containing digital core reconstruction method of a time sequence coupling constraint field, and belongs to the field of digital rock physics and pore scale multiphase medium reconstruction. The hydrate is merged into an equivalent solid boundary set, and a constraint field is reconstructed on effective pores, so that pore topological change caused by hydrate occupation can be reflected by gas phase generation, and a four-phase distribution result with higher physical consistency is obtained. The method comprises the following steps: firstly, generating a hydrate phase in an initial pore domain, and merging the hydrate phase into an equivalent solid boundary set to reflect occupation and constraint effects of hydrate growth on pore topology; then, constraint field reinitialization is executed on the effective pore domain after the hydrate is generated, and a secondary distance potential field jointly constrained by the rock skeleton and the hydrate boundary at the same time is obtained; secondly, generating gas phase distribution on the secondary distance potential field according to a preset gas phase occurrence mode; and finally, automatically defining the remaining pores as a water phase, and synthesizing to obtain the four-phase digital core meeting a mutual exclusion complete rule.

The invention relates to an enhanced imbibition micro-pore wetting index spatio-temporal evolution calculation method, and belongs to the technical field of unconventional oil and gas development. The method comprises the following steps: firstly, measuring nuclear magnetic resonance spectrums of simulated oil with different viscosities, and fitting a relation between a geometric mean value and the viscosities; then, testing an original spectrum of the rock sample, saturating oil, and carrying out an enhanced imbibition experiment to obtain spectrum data after different imbibition time; and based on a dynamic wetting index calculation formula and in combination with oil phase viscosity parameters, quantitatively characterizing a change rule of wettability of each pore scale along with time, and drawing a micro-pore wetting evolution chart. According to the method, accurate dynamic analysis of the wettability of the pores is realized, a space-time evolution mechanism of wettability reversal is disclosed, and theoretical and technical support is provided for efficient development of shale oil.

According to the CO2-water-oil-shale multi-phase system wettability evaluation method and device, a traditional contact angle measurement method and the nuclear magnetic resonance technology are combined, the defect that micro-nano scale pore wettability cannot be quantitatively studied through the contact angle measurement method is overcome, and the accuracy of the shale pore scale wettability through the nuclear magnetic resonance technology is enhanced; the method comprises the following steps: simulating a high-temperature and high-pressure environment of a shale reservoir, establishing a CO2-water-oil-shale multiphase coexistence system, realizing comprehensive evaluation of the wettability of the shale reservoir by combining a macro scale and a micro scale, and realizing fine characterization of the wettability from the macro scale to the micro scale; and the method for accurately evaluating the wettability of the shale reservoir in the CO2-enhanced shale oil and gas reservoir development and geological burying process is created. The scheme is simple, convenient, efficient, accurate, comprehensive and high in applicability, lays a solid foundation for CO2 large-scale shale oil and gas reservoir development and CO2 long-term storage, and has a wide application prospect.

The invention discloses a low-permeability reservoir nonlinear seepage model construction method and a numerical simulation method, and the method comprises the steps: carrying out flow experiments of micro circular tubes with different inner diameters based on an equivalent capillary bundle model of a core in a low-permeability reservoir, so as to construct a boundary layer fluid thickness characterization model of the low-permeability reservoir; constructing a non-linear seepage model of the low-permeability reservoir based on a non-linear seepage theory of the low-permeability reservoir; and based on a fitting result of the boundary layer fluid thickness characterization model and the non-linear seepage model of the low-permeability reservoir, correcting model parameters in the non-linear seepage model of the low-permeability reservoir by using the boundary layer fluid thickness characterization model so as to obtain the non-linear seepage model of the low-permeability reservoir considering the change characteristics of the boundary layer fluid thickness. The method not only considers the influence of the microscopic seepage mechanism of the low-permeability reservoir, but also defines the change relation of the boundary layer thickness of the low-permeability reservoir along with the displacement pressure gradient, and realizes the nonlinear seepage numerical simulation of the low-permeability reservoir by correcting the pore scale numerical parameters.

The invention belongs to the technical field of preparation of pore-fracture dual-permeation models, and particularly relates to a preparation method of a fracture-pore dual-permeation model and a test method of permeability of gravelly soil with fracture-pore dual-permeation property. The method comprises the following steps: performing silica gel reverse molding on a crack model to obtain a silica gel mold; liquid paraffin is injected into the silica gel mold, and then a paraffin crack model is obtained after the liquid paraffin is cooled and solidified; gravelly soil and glue are mixed to obtain a mixture, a mold is filled with the mixture, the paraffin fracture model is placed in the mixture in the filling process, and an initial sample is obtained; and carrying out heat treatment on the initial sample, and cooling to obtain the fracture-pore double-permeation model. The preparation method provided by the invention solves the technical problems of uncontrollable fracture shape and non-uniform porosity in the traditional pore and fracture dual-permeability research, has the advantages of designable fracture shape and accurate porosity regulation and control, and is suitable for the permeability research of the gravelly soil pore size in a laboratory environment.

The present invention provides a method for generating a pore structure and predicting permeability of an anisotropic fibrous material.SOLUTION: A single fiber rod model is established according to structural characteristic parameters such as the zenith angle θ and the circumferential angle φ of the fiber material, the process of establishing the single fiber rod is repeated until the target porosity ε of the material is reached, the allowable minimum gap dgap between the fibers and the maximum number of iterations Nmax are used as constraints in this process, and then a finite volume simulation program created based on the open source fluid dynamics library OpenFOAM is used to simulate and predict the permeability of the generated anisotropic fiber material. In addition to generating the pore scale characterization structure of the fiber material, the present invention can develop a prediction method of the permeability of the fiber material in combination with the finite volume method, quantitatively analyze the influence of structural parameters on the permeability, and provide a reference for the design and manufacture of the fiber material.SELECTED DRAWING: Figure 1

The application discloses a kind of implementation dissolution-precipitation dynamic coupling's saline aquifer CO2 mineralization storage pore scale numerical simulation method, comprising: constructing geometric model under pore scale;The flow velocity distribution and pressure distribution of geometric model in time and space are calculated;Reaction migration model of the CO2 mineralization storage of saline aquifer is constructed;Kinetics reaction rate equation and porosity dynamic evolution equation are established, ion product-solubility product judgment statement is introduced, the reaction migration model is solved, and CO2 deep saline aquifer mineralization storage reaction migration numerical simulation is completed.The application is coupled by DBS equation and ADE equation, realizes the solution reaction migration numerical simulation under pore scale, simplifies the complex reaction migration numerical simulation solving process;In the process of solving reaction migration, dissolution and precipitation process are coupled simultaneously, more close to real situation;It is suitable for operation under a variety of working conditions, extracts solute transport and dissolution-precipitation rule under different conditions, and provides support for experimental research.

The application discloses a cross-scale numerical simulation method based on micro-macro mixing. The method comprises the following steps: S1, realizing downscaling generation from a macroscopic reservoir scale grid to a micro-pore scale grid; S2, establishing a dual grid system consistent with the size of the macroscopic reservoir scale grid; S3, considering the boundary condition, decomposing pressure and flow rate into a plurality of base functions to construct a local micro-flow equation; S4, establishing a quantitative conversion relationship between micro-pore flow characteristics and macro-flow parameters; and S5, realizing cross-scale conversion of the macroscopic scale and the micro-pore scale. The method has the beneficial effects that the simulation precision is improved while the calculation efficiency is ensured, local heterogeneity is accurately captured, and remaining oil is accurately identified.

The invention provides a double karst water-containing medium physical model construction method and device, and relates to the technical field of karst geology, and the method comprises the steps: obtaining a real rock core structure; performing three-dimensional scanning on the real rock core structure, inputting a three-dimensional scanning image into a preset three-dimensional image analysis model for three-dimensional reconstruction, extracting a network, and constructing a pore network model; extracting pore structure features based on the pore network model, and constructing a pore network three-dimensional model by inputting the pore network model into a preset multi-physics field coupling model for seepage simulation; according to pore size distribution and permeability difference in the pore network three-dimensional model, determining a space division boundary of the porous matrix block and the karst pipeline to obtain a porous medium structure; and performing integrated forming treatment and physical verification on the porous medium structure to obtain the double karst water-containing medium physical model. According to the method, the problem that a physical model cannot truly reflect capability and engineering applicability is solved.

The embodiment of the present application provides a kind of for determining reservoir multiscale shale oil mobility method, device and storage medium, belong to unconventional oil and gas development technical field.The method for determining reservoir multiscale shale oil mobility includes: obtaining the component content of multiple mineral components to be measured in multiple shale samples in the shale reservoir to be measured and the recovery rate of multiple shale samples under multiple pore scales;According to the component content of each mineral component to be measured in multiple shale samples and the recovery rate of multiple shale samples under each pore scale, determine the component content-mineral component content-recovery rate correlation degree value of the component content of each mineral component to be measured and the recovery rate of shale sample under each pore scale;According to the component content of multiple mineral components to be measured and the corresponding component content-mineral component content-recovery rate correlation degree value, determine the shale oil mobility of the shale reservoir to be measured under each pore scale.The present application can realize the quantitative characterization of the shale oil mobility of reservoir.

The invention provides a shale oil reservoir displacement effect prediction method and device, equipment and a medium, and belongs to the technical field of shale oil displacement. According to the method, the volume fraction and the capillary pressure of each phase of carbon dioxide, oil and water are obtained, and a shale oil pore scale carbon dioxide, oil and water three-phase displacement model is constructed through a phase field method; drawing a simulation domain according to the shale oil reservoir pore size distribution, performing grid division on the simulation domain, and setting initial conditions and boundary conditions; the displacement behavior of the nano-pore shale oil in the three-phase displacement mode is calculated, and the three-phase displacement effect is predicted according to the displacement behavior of the nano-pore shale oil in the three-phase displacement mode. Therefore, the three-phase displacement effect of the shale oil can be predicted in a modeling mode for the small-pore shale oil reservoir, the problem that the shale oil is difficult to develop under the conditions of extremely low permeability and pore non-connectivity is solved, and then the shale oil displacement development efficiency is improved.

The present application belongs to the field of unconventional oil and gas resource efficient development technology, and particularly relates to a system and method for accurately quantifying critical startup flow velocity of particles under complex flow field. The system for accurately quantifying critical startup flow velocity of particles under complex flow field comprises a pore medium real pore structure characterization device, a pore etching model, a pore scale flow field visualization device and a data acquisition and processing device. The data acquisition and processing device comprises a high-speed image acquisition module, a two-dimensional PIV software and a calculation module. The high-speed image acquisition module is used to acquire particle images captured by a particle image velocimetry module. The two-dimensional PIV software is used to calculate a velocity vector field based on the particle images. The calculation module is used to calculate the critical startup flow velocity of target particles based on the velocity vector field. The system for accurately quantifying critical startup flow velocity of particles under complex flow field can realize simulation of complex flow field of target porous medium and accurate calculation of critical startup flow velocity.

The invention aims to provide a method for generating a three-dimensional point track of a human face. The method comprises the following steps: taking a visual angle directly facing the human face as a reference visual angle; obtaining a two-dimensional key point set and a corresponding three-dimensional key point set by using the reference view angle; utilizing the three-dimensional key point set to obtain a two-dimensional projection point set of any three-dimensional key point under the reference view angle in other visible view angles; performing frame-by-frame matching on any key point in the two-dimensional key point set to form an auxiliary track of the key point; performing cross-view information fusion and trajectory completion through corresponding mark positions in the two-dimensional projection point set to obtain a completed two-dimensional trajectory, and finally obtaining a three-dimensional space-time motion trajectory of any key point; according to the method, robust frame-by-frame key point tracking is realized, and tracking errors caused by illumination changes, facial expression changes and weak texture areas are effectively reduced.

The application discloses an experimental method for visualizing gas-water mutual displacement circulation test, which comprises the following steps: fixing a transparent visual flow model on an imaging platform, and connecting a gas injection channel and a liquid injection channel to both ends of the internal network channel structure of the model; injecting liquid to make the network channel structure reach an initial saturation state and collect an initial image; injecting gas to displace liquid and complete a gas-water displacement process and collect process images; injecting liquid to displace gas and complete a water-gas displacement process and collect process images; alternately repeating the gas-water displacement and water-gas displacement for a preset number of times to complete a multi-cycle circulation test; processing each cycle image, identifying gas phase and liquid phase regions, calculating gas phase saturation, liquid phase saturation and residual gas saturation, and obtaining the evolution law of interface migration and displacement efficiency. The application realizes intuitive and continuous observation of pore-scale interface migration in the multi-cycle gas-water mutual displacement process and quantitative analysis of the residual gas accumulation law.

The invention discloses a micro-fluidic chip capable of controlling mixed wettability based on dynamic thermal response and a visual experiment device and method, and belongs to the technical field of porous medium research, the micro-fluidic chip comprises a micro-channel substrate module and an upper cover plate which are connected in a sealed mode, the micro-channel substrate module comprises a borosilicate glass substrate and a micro-channel structure on the surface of the borosilicate glass substrate, and the upper cover plate is connected with the borosilicate glass substrate. The micro-channel structure can simulate micro-pores and throat structures of real oil reservoir rocks; a dynamic wettability surface layer is constructed on the surface of the micro-channel structure, and hydrophilicity / hydrophobicity of different areas can be adjusted in real time according to displacement requirements; the micro-channel substrate module can be connected with the multi-stage temperature control module, so that accurate temperature control of a local area is realized, a complex temperature gradient field is constructed, and temperature distribution characteristics of a real oil reservoir are accurately simulated; according to the visualization experiment device, visualization monitoring of the whole CO2 displacement process under the pore scale is achieved through the camera and the infrared thermal imager, and the occurrence form of CO2 and the adsorption and deposition conditions of asphaltene particles can be visually observed.

The invention discloses a method for predicting the diffusion behavior of underground hydrogen in the pore scale of water-containing clay minerals and application, and belongs to the technical field of underground hydrogen energy storage and unconventional gas migration prediction. Performing energy minimization and pre-balance on the initial pore model of the water-containing clay mineral through a molecular dynamics method; filling hydrogen molecules under given temperature and pressure conditions through a giant regular Monte Carlo method, and correcting the hydrogen pressure through an SRK-EOS state equation; according to the method, the temperature and the fugacity are used as input parameters, hydrogen diffusion simulation is carried out through a molecular dynamics method, the mean square displacement of hydrogen in the pores is calculated, and the self-diffusion coefficient is obtained, and the diffusion rate change rule of the hydrogen in the clay pores under the conditions of different water film thicknesses, salinity and temperature pressure can be quantitatively represented; diffusion inflection points, diffusion suppression stages and migration limitation mechanisms caused by water film or water bridge structures are disclosed.

This invention discloses a multi-field coupled core rheological testing device in a carbon dioxide environment, belonging to the field of core rheological testing technology. The CO2 chemical potential and phase state closed-loop adaptive control module is used to maintain or track the CO2 chemical potential and phase state at the pore scale of the sample according to a preset target during the experiment. It also performs closed-loop linkage control of the pore chemical potential and phase state information with the axial loading unit and confining pressure system, thereby achieving coupled control and synchronous data acquisition of chemical-mechanical-thermal-seepage processes. This invention, through the CO2 chemical potential and phase state closed-loop adaptive control module, achieves real-time measurement and tracking of the set CO2 chemical potential and phase state target at the pore scale. This solves the problems of traditional testing devices being unable to maintain a stable chemical potential or repeatedly control the gas-liquid phase state at the pore scale, and unable to feed back chemical field changes to the mechanical loading strategy in real time. This significantly improves the repeatability and spatiotemporal controllability of chemical erosion experiments, reduces the frequency of manual intervention, and lowers the risk of instability.

A method for calibrating a direct flow simulation of a rock sample involves providing a 3D image of a rock sample and generating a segmented structural image of the rock sample from the 3D image by selecting voxels to represent either a pore space or a solid material. Fluid flow is simulated on the segmented structural image with a direct flow simulation. A 3D spatially-resolved fluid velocity map is generated for one or more fluid phases at a pore-scale resolution using pulsed field gradient nuclear magnetic resonance imaging. The simulated fluid flow and the 3D spatially-resolved fluid velocity map are compared to calibrate the direct flow simulation across the rock sample.

The invention discloses a multi-scale visual analysis method for an aeration zone water and salt migration driving mechanism, and belongs to the technical field of hydrogeology and environment monitoring. According to the method, a brand new multi-physical field coupling driving model is established, a spatial-temporal heterogeneity quantitative index of moisture-salt migration in a non-uniform pore medium is introduced, and continuous visual analysis from a micro pore scale to a macro region scale is realized by combining an independently designed visual mapping function. The method comprises the following steps: collecting multi-source heterogeneous hydrogeological data; constructing a driving potential field model based on pore network topology evolution; defining a coupling kinetic equation of salt transportation and a multi-scale feature extraction operator; designing a visual rendering parameter mapping rule; and the water-salt migration process is presented through a multi-dimensional dynamic map. The method can accurately reveal the driving mechanism of water and salt migration in the aeration zone and the cross-scale association rule of the driving mechanism, and is suitable for the fields of soil improvement, saline-alkali soil treatment, groundwater pollution prevention and control and the like.

This invention belongs to the field of oil and gas reservoir development and discloses an integrated simulation method for water-lock damage in tight gas reservoirs involving fracturing and flowback. By acquiring scanning data from tight reservoir cores, a binary digital core model reflecting the true pore structure is constructed after preprocessing. A pore-scale two-phase flow numerical calculation model is established using the color gradient multiphase flow lattice Boltzmann method. Based on this model, the fracturing fluid invasion and flowback processes are simulated in an integrated manner, dynamically tracking the migration, distribution, and retention evolution of the water phase in the pore network. The water-lock permeability damage rate is quantitatively determined by calculating the gas phase permeability before and after fracturing fluid invasion. Furthermore, sensitivity analysis is conducted on key factors such as fracturing fluid viscosity, interfacial tension, and reservoir properties. This invention achieves continuous coupled characterization of the entire fracturing-flowback process, revealing the dynamic formation mechanism of water-lock damage at the microscopic level, and solving the problem of poor stability of existing pore-scale simulation methods in high-density gas-water systems.

The invention discloses a carbon dioxide environment multi-field coupling rock core rheological testing device, and relates to the technical field of core rheological testing, a CO2 chemical potential and phase state closed-loop adaptive control module is used for maintaining or tracking the CO2 chemical potential and phase state of the pore size of a sample according to a preset target in the testing process; and closed-loop linkage control is carried out on the pore chemical potential and phase state information, the axial loading unit and the confining pressure system, so that chemical-mechanical-thermal-seepage coupling control and synchronous data acquisition are realized. Through the CO2 chemical potential and phase state closed-loop adaptive control module, real-time measurement and tracking of a set CO2 chemical potential and phase state target at a pore scale are realized, and the problems that a traditional testing device cannot maintain a stable chemical potential or can repeatedly control a gas-liquid phase state at the pore scale, cannot feed back chemical field change to a mechanical loading strategy in real time, and cannot realize real-time measurement of the pore scale are solved. The repeatability and the space-time controllability of a chemical erosion test are remarkably improved, the manual intervention frequency is shortened, and the instability risk is reduced.

The present application relates to a kind of laboratory for studying the method and device for solving near well pollution with ultrasonic visualization.The present application relates to the technical field of oil and gas field development and stimulation, and the device is composed of ultrasonic system, displacement system, visualization monitoring system and data acquisition and control system;Focused ultrasonic transducer is accurately acted on microfluidic core model in cooperation with three-dimensional displacement platform, displacement system contains annular pressure automatic tracking module to simulate formation pressure, and high-speed camera realizes pore scale dynamic observation.The method comprises the following steps: establishing pollution model, applying controllable ultrasonic wave, in-situ visualizing collecting cavitation bubble and pollutant transport process, synchronously collecting seepage data and correlating and analyzing plugging removal mechanism.The present application can real-time observe the microcosmic dynamics process of ultrasonic plugging removal, quantify the relationship between frequency, power and plugging removal efficiency, and is suitable for mechanism research and parameter optimization of various near well pollution types, and solves the "black box" problem that traditional technology cannot in-situ visualize observation.