95 results about "Pore scale" patented technology

The invention provides a pore-scale underground natural hydrogen migration and accumulation behavior prediction method, and belongs to the field of underground natural hydrogen exploration and exploitation. Comprising the following steps: reconstructing an underground porous medium according to a real geological structure image; establishing an empirical formula of fluid attributes such as wettability, interfacial tension and viscosity of the hydrogen-water-rock system and temperature, pressure, salinity and rock type; establishing a flow equation of the hydrogen-water two-phase system in the porous medium; after initial conditions and boundary conditions are determined, the initial distribution, migration and aggregation process of natural hydrogen in the porous medium is simulated; and after the flow is stable, a migration and accumulation image of the hydrogen-water-rock system and a hydrogen recovery rate change curve are obtained. The hydrogen-water two-phase migration-accumulation model constructed by the method is suitable for the characteristics of high density ratio and high viscosity ratio of hydrogen and water, and is good at treating a porous medium complex structure and identifying a hydrogen-water interface; and the method is oriented to a real underground reservoir, and is suitable for predicting the hydrogen-water-rock migration and accumulation process under no environmental factors.

The invention discloses a CO2-EGR visual monitoring method based on nuclear magnetic resonance. The CO2-EGR visual monitoring method aims at solving the problem that dynamic observation of the pore scale gas drive process is insufficient in the traditional technology. Multi-sequence nuclear magnetic resonance monitoring is synchronously executed, a T2 spectrum is obtained through a CPMG sequence to analyze CH4 content changes, a layered T2 spectrum is generated through an SE-SPI sequence to represent axial fluid distribution, a one-dimensional frequency signal is collected based on a GR-HSE sequence to track a displacement leading edge in real time, and fluid migration visualization is achieved in combination with an HSE overall imaging sequence. The system integrates a gas injection unit, a high-pressure-resistant nuclear magnetic holder, a back pressure controller and a data acquisition module, and is hermetically connected through a high-pressure-resistant pipeline to form a closed-loop experiment system. According to the method, displacement front recognition, displacement process in-situ analysis and quantitative characterization of the displacement efficiency in the non-intrusive CO2-EGR process are achieved for the first time, the CO2-EGR visualization bottleneck is broken through, and a scientific basis is provided for optimizing gas injection parameters and improving the natural gas recovery rate and the carbon sequestration efficiency.

The invention belongs to the technical field of computer aided design, and provides a C / C composite material thermochemical response and pore scale structure evolution prediction method, which comprises the following steps: constructing a geometric model of the pore scale of a rocket engine jet pipe; establishing a fluid flow model in a D2Q9 form; establishing a multi-component mass transport model in a D2Q5 form; establishing a heat transfer model in a D2Q5 form; establishing a heterogeneous chemical reaction model of the fluid-solid boundary; establishing an updating model of the composite material based on a volume pixel method; and based on a geometric model, a fluid flow model, a multi-component mass transport model, a heat transfer model, a heterogeneous chemical reaction model and an update model, predicting the thermochemical response and pore scale structure evolution of the C / C composite material in the rocket engine nozzle. The method is provided for studying the ablation process of the C / C composite material, and theoretical basis and guidance direction are provided for thermal performance study and fine design of the spray pipe.

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 present application discloses a system for simulating steam channeling plugging and profile control in heavy oil reservoirs based on microfluidics, which includes two etched transparent dielectric sheets with pore structures for reflecting steam channeling dominant channels in the middle disposed on a heating device. The injection parts of the etched transparent dielectric sheets are connected with a steam generating device, an oil storage device and a particle suspension storage device, and the other ends of the two are commonly connected to a first displacement device. The other end of the steam generating device is connected to a second displacement device. The oil outlet parts of the etched transparent dielectric sheets are connected with a liquid production collection device and an image acquisition device is arranged above. The image acquisition device and the heating device are electrically connected to a data acquisition and analysis device. This system enables experimenters to observe the plugging and profile control process of steam and plugging agent particles and the oil production effect after steam channeling in heavy oil reservoirs at the pore scale, further explore the development potential after steam channeling in heavy oil reservoirs, and has higher simulation accuracy. The present application also discloses a method for simulating steam channeling plugging and profile control in heavy oil reservoirs based on microfluidics.

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 relates to a multi-scale prediction method for the oxidative ablation behavior of a carbon / carbon porous heat-proof material, and belongs to the technical field of aerospace science, in particular to a multi-scale prediction model for the oxidative ablation behavior of the carbon / carbon porous heat-proof material. A chemical reaction standard enthalpy value and reaction activation energy are analyzed based on a gas-solid interface micro-model of a carbon / carbon porous heat-proof material, and then pore scale fluid mechanics calculation is performed in combination with a porous medium model; explaining an evolution mechanism between gas-solid interfaces by using a micro-scale and pore-scale simulation method, and predicting an ablation process surface evolution process; according to the invention, fluid flow, thermal reaction and heterogeneous chemical reaction in the porous medium in the ablation process can be coupled and simulated at the same time; according to the method, the action mechanism of the heterogeneous chemical reaction at the gas-solid interface in the oxidation ablation process of the carbon / carbon porous heat-proof material can be disclosed, and the distance change after ablation and the ablation surface roughness in the ablation process can be predicted more accurately.

The invention relates to a coastal zone sediment erosion pore scale flow field observation system and observation method. The observation system comprises a wave-flow water tank, a sediment accumulation body arranged in the wave-flow water tank and PIV equipment used for observing the internal flow field and the pore size of sediment. A wave making plate and a wave dissipating plate opposite to the wave making plate are arranged in the wave flow water tank, experimental fluid used for simulating waves is arranged between the wave making plate and the wave dissipating plate, and a wave height meter floats on the experimental fluid; the sediment accumulation body is formed by accumulation of transparent solid particles with the same refractive index as the experimental fluid; the PIV equipment comprises a laser light source and a camera, the laser light source is focused on the sediment accumulation body, and the camera directly faces the sediment accumulation body and is used for collecting images. Compared with the prior art, a clearer sediment pore internal flow field image is obtained through the combination of the refractive index matching technology and the image particle velocity measurement method, so that effective observation of the pore scale flow field eroded by the sediment in the coastal zone is realized.

The invention relates to the technical field of numerical reservoir simulation, in particular to a shale volatile oil reservoir simulation method considering fracturing fluid injection phase change, comprising: acquiring shale volatile oil reservoir development parameters and core data of a target block; the method comprises the following steps: establishing a shale volatile oil reservoir numerical basic simulation model according to shale volatile oil reservoir development parameters, preparing a micro-fluidic chip according to core data, performing pore scale bubble point test, and correcting parameters of the basic simulation model according to bubble point data after fracturing fluid injection; establishing a shale volatile oil reservoir numerical value complete simulation model considering the fracturing fluid injection phase change, and analyzing the influence of the injected fracturing fluid on the oil and gas yield by using the shale volatile oil reservoir numerical value complete simulation model. According to the method, the production rule in the shale volatile oil reservoir exploitation process can be accurately obtained, the numerical simulation method of the shale volatile oil reservoir is perfected, and the method has important significance for guiding efficient development of the shale volatile oil reservoir.

The invention discloses a physical model system for a multi-scale reaction transportation process of a salt water reservoir, which comprises a physical modeling module and a numerical solution module, and is characterized in that the physical modeling module is used for realizing unbalanced mass transfer through micron-scale multi-field coupling modeling, providing a physical basis for cross-scale parameter transmission, and solving the numerical solution module; the physical modeling module comprises a geometric reconstruction module, a multi-field coupling module and a multi-physical process collaboration module, the numerical solution module is used for realizing efficient solution of a pore scale multi-field coupling model, the pore scale and the Darcy scale are associated with each other, and the numerical solution module comprises an initialization module, an iteration solution module and a multi-scale parameter generation module; by constructing a pore size modeling and numerical solution dual-module cooperative system, high-precision three-dimensional reconstruction and multi-field coupling dynamic simulation of a micron-sized pore structure are realized, and deep association of a fluid transportation mechanism on a micro-pore scale and fluid transportation on a macro-Darcy scale is realized through scale upgrading.

The invention discloses a pore-scale shale oil in-situ modification multi-field coupling numerical simulation method, and relates to the technical field of shale oil exploitation. The system comprises a model hypothesis module, a mathematical model module, a model solving and parameter setting module and a result analysis module. Based on the system, the invention further provides a multi-field coupling numerical simulation method for in-situ upgrading of shale oil with medium and low maturity in pore scale, and the multi-field coupling phenomenon in the in-situ upgrading process of shale oil with medium and low maturity can be accurately simulated through reasonable model assumption and mathematical model construction in combination with an effective numerical solution strategy and parameter setting. According to the method, dynamic changes of various chemical components in the kerogen multistage pyrolysis process and interaction of a chemical field, a temperature field and a seepage field are considered, and the simulation result is more accurate and reliable; in addition, through grid independence verification, a proper grid subdivision scheme is selected, and the calculation efficiency is improved while the calculation precision is ensured.

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 invention discloses a shallow heavy oil reservoir hot nitrogen foam multi-stage slug cooperative displacement method and system, and the method comprises the steps: constructing a basic database, calling a multi-stage slug dynamic adaptation optimization algorithm to obtain an initial slug parameter combination, inputting a pore scale interface competition dynamic network model to simulate the displacement efficiency, and carrying out the multi-stage slug cooperative displacement. Actual data are collected and compared through hot nitrogen foam displacement real-time monitoring and an intelligent regulation and control platform, parameters are adjusted, model boundary conditions are updated till deviation reaches the standard, slug injection is conducted according to optimized parameters, and monitoring and feedback are continuously conducted. The system comprises a hot nitrogen foam preparation and injection unit, a reservoir parameter monitoring unit, an algorithm operation and model processing unit, a data storage and management unit, a system control and instruction output unit and a data interaction and visualization unit which work cooperatively. According to the method and system, slug parameter dynamic optimization and displacement process real-time management and control are achieved, the adaptability of slugs and reservoirs is improved, gas channeling is reduced, and the recovery efficiency and development efficiency of shallow heavy oil reservoirs are improved.

The utility model discloses a high-performance infrared imaging device for foam material pore dimension detection, which comprises an experiment cylinder, the outer surface of the upper end of the experiment cylinder is in threaded connection with a cylinder cover, the middle parts of the outer surfaces of the two sides of the experiment cylinder are fixedly provided with fixing blocks, the outer surfaces of the upper ends of the fixing blocks are fixedly provided with supporting columns, and the supporting columns are fixedly provided with supporting columns. Two groups of connecting plates are fixedly mounted on the outer surface of the upper end of the supporting column, a thermal imager is fixedly mounted between the two groups of connecting plates, an infrared window is formed in the middle of the outer surface of the upper end of the barrel cover, the thermal imager is located right above the infrared window, an objective table is arranged in the middle of an inner cavity of the experiment barrel, and the objective table is located right above the thermal imager. An adjustable thermocouple and a fixed thermocouple are arranged on the periphery of the objective table. According to the high-performance infrared imaging device for detecting the pore size of the foam material, disclosed by the utility model, the infrared radiation characteristics of a rib framework of the foam material can be clearly observed.

The invention discloses a microscale shale pore CO2 oil displacement simulation method based on computational fluid dynamics (CFD). The microscale shale pore CO2 oil displacement simulation method is suitable for low-permeability and low-porosity oil reservoir development. According to the method, a porous medium numerical model is constructed, CO2-crude oil two-phase flow characteristics under different pore structures and stratum conditions are systematically researched, and a pore scale fluid distribution rule and displacement efficiency are mainly analyzed. The CFD numerical simulation technology is adopted, key parameters such as the CO2 diffusion and migration rule in the pores and residual oil saturation distribution are obtained, and the CO2 oil displacement mechanism in the micro-nano-scale pores is revealed. By comparing displacement effects under different environmental parameters (pressure, temperature and the like) and pore configurations (pore size distribution, connectivity and the like), a quantitative relation model of pore structure-oil displacement efficiency is established. The method provides theoretical basis and technical support for optimization of a low-permeability reservoir CO2 oil displacement scheme, and has important guiding significance for improving the unconventional oil and gas recovery ratio and CO2 geological sequestration.

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 invention discloses a component natural gas pore network stress coupling simulation method and system and a medium. Relates to the technical field of natural gas reservoir model simulation. Through a multi-component diffusion flow coupling model considering effective aperture change, real-time change of pore radius and permeability along with reservoir stress and seepage phenomena of pore change along with stress and flow coupling of multi-component gas in a pore scale are displayed, and meanwhile, aiming at the multi-component diffusion flow coupling model considering effective aperture change, the permeability of the multi-component gas is improved. A special coupling simulation method is designed, a multi-component gas pore scale seepage model is established, discretization processing and model solving are carried out on the multi-component gas pore scale seepage model in combination with throat characteristic parameters, and dynamic coupling simulation of component natural gas pore network stress is achieved. The change of the relative permeability of the fluid under different stress conditions is shown, and the adaptability of a multi-component diffusion flow coupling model is enhanced.

The invention discloses a microcosmic numerical simulation method for pore-scale polymer oil displacement. The method comprises the following steps: obtaining basic data of polymer, oil, water viscosity, oil-polymer and oil-water interfacial tension; initializing partial content data of the basic data; the speed distribution of the polymer, oil and water in the pore space is obtained; adopting a polymer spatial distribution tracking model to obtain distribution of polymers in space; adopting an oil space distribution tracking model to obtain the distribution of oil in the space; obtaining an oil-water interface curvature and an oil-polymer interface curvature; solving the viscoelastic stress tensor of the polymer; and carrying out viscous component and elastic component decomposition on the solved viscoelastic stress, and repeating the steps. According to the method, the strategy of separating and dispersing the viscous component and the elastic component is introduced, the stability of the algorithm is improved, the high-stability numerical simulation method for pore-scale polymer oil displacement is provided, and efficient tracking of pore-scale flow in the polymer oil displacement process is achieved.

The invention discloses an ultrasonic enhanced water-oil displacement recovery ratio experiment system based on CT real-time imaging, and belongs to the technical field of oil and gas exploitation experiments. The system is composed of a core clamping and pressure control system, an ultrasonic excitation system, an injection and extraction system, a monitoring and data acquisition system and a data analysis and optimization system. A core holder can accurately simulate underground reservoir pressure and fluid conditions. The ultrasonic excitation system reduces the oil-water interfacial tension through the cavitation effect and micro-vibration, and improves the fluidity and release effect of oil drops; the injection and extraction system is used for accurately controlling the injection flow rate and pressure of displacement liquid to form a stable oil displacement gradient; the monitoring system dynamically captures the core internal oil-water leading edge propulsion, residual oil distribution and ultrasonic cavitation bubble evolution process, and visualization of an ultrasonic energy transfer path under the pore scale is achieved for the first time. The system can effectively research the influence of ultrasonic enhancement on the water drive recovery efficiency, and provides experimental basis and technical support for improving the oilfield development efficiency.

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 invention discloses a two-phase displacement numerical simulation method based on a multi-pipe-diameter capillary model, and belongs to the field of pore scale displacement numerical simulation. The method comprises the following steps: firstly, establishing a multi-pipe-diameter capillary physical model based on flow channel size characteristics of a low-permeability reservoir; setting a capillary group as a displaced phase domain according to the number of pipe diameters required to be researched and the size of the capillary diameter, and additionally setting a rectangle I to represent a displacement phase source; and then taking the multi-pipe-diameter capillary physical model as a computational domain, further constructing a two-phase displacement numerical simulation method, and simulating the displacement process on the basis of the two-phase displacement numerical simulation method. According to the method, the single form of an existing capillary tube model is overcome, the multi-pipe-diameter capillary tube physical model is constructed, and the design purpose of the model is to determine the minimum pipe diameter threshold value capable of causing the displacement phenomenon when the capillary tube displacement behavior is explored under the multi-pipe-diameter coexistence condition; and whether the movement of fluid in a smaller pipe diameter can be effectively activated or not by adjusting injection-production parameters through a numerical simulation means is further discussed.

The invention discloses an ion matching fine water-gas alternating drive microscopic visual simulation method based on a reverse micelle effect. The method comprises the following steps: S101, carrying out a contact experiment on CO2, saline water and crude oil to form a reverse micelle structure cluster on an oil-water interface, and separating to obtain reverse micelle-removed crude oil; s102, extracting a pore throat structure of the rock core sample through CT scanning and image processing, and making a microscopic model containing the pore throat structure; and S103, designing and building a microscopic visual experiment platform, respectively carrying out ion matching fine water-gas alternating flooding experiments on the crude oil in the step S101 and the reverse micelle-removed crude oil in the microscopic model in the step S102, and observing multi-phase fluid flow under the pore scale. According to the method, dynamic characteristic development, wettability change and fluid saturation distribution are dynamically monitored in the process, the synergistic advantage of ion matching water drive and CO2 drive is explained from the pore scale, and a theoretical basis is provided for popularization and application of ion matching fine water-gas alternating drive.

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.

A relative permeability curve calculation method based on a phase field model relates to the technical field of oil and gas development, and comprises the following steps: selecting a core sample to establish a pore-scale model, performing a single-phase flow simulation, calculating the absolute permeability of the pore-scale model, performing a gas-water two-phase flow simulation, respectively calculating the gas and water phase fluid distribution volume fractions and the total fluid volume flow rate of the pore-scale model in each time interval, then respectively calculating the total gas and water two-phase fluid flow rates of the pore-scale model in each time interval, respectively calculating the volume flow rates of the gas and water phase fluids in each time interval, further calculating the corresponding relative gas phase permeability and relative water phase permeability in each time interval, and drawing a relative permeability curve in combination with water saturation; the relative permeability curve in the present invention can better characterize the fluid physical properties of the complex porous medium pore model, and thus accurately obtain the seepage characteristics of the fluid in the porous medium model.

The invention discloses a porous medium heat and mass transport cross-scale calculation method, system and device and a medium. The porous medium heat and mass transport cross-scale calculation method comprises the following steps: determining a porous structure, a heat and mass transport physical process and a definite solution condition of a porous medium; dividing the porous structure into a plurality of macroscopic units, assigning initial values to the macroscopic transport parameters, and repeating the following steps until the macroscopic transport parameters converge; solving the macro-scale physical field; according to the macroscopic scale physical field, determining a pore scale boundary condition of each macroscopic unit, and based on the pore scale boundary condition and the porous structure of each macroscopic unit, obtaining a pore scale physical field; and updating macroscopic transport parameters according to the pore scale physical field. The method has the advantages of high calculation precision and high calculation speed in the porous medium heat and mass transportation process, and is low in memory occupation, relatively low in requirement on calculation hardware and wide in application range.

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.