149 results about "Low permeability" patented technology

The invention discloses a soil-pile foundation collaborative response seismic liquefaction discrimination device and method based on seismic oscillation time-frequency characteristics, and the method comprises the steps: building a multi-field coupling evolution model comprising a soil body domain, a fluid domain and a structural body, constructing a variable-scale grid architecture through a finite element method, balancing the high sensitivity and calculating the load, and carrying out the calculation of the load. Meanwhile, the fluid domain is directly coupled with the soil body unit through the shared node, and the Poisson's ratio is dynamically calibrated according to the void ratio. The multi-field coupling modeling mode can accurately simulate a soil-water-structure collaborative response mechanism, the problem of time-frequency characteristic mismatch caused by a scale effect in the prior art is avoided, and the strength degradation law and the aging characteristic of the in-situ soil body are accurately reflected. Compared with a traditional physical model which cannot reproduce nonlinear dynamic response under complex geological conditions, the method has the advantages that accurate description of high void ratio and low permeability of the soft sand is realized through numerical modeling, and the reliability of seismic liquefaction judgment results is further improved.

The invention discloses a shallow shale gas self-sealing reservoir formation identification method, which comprises the following steps: firstly, carrying out dual-energy CT scanning on a shale full-diameter core sample to obtain DEI values, and the difference of the DEI values embodies different lithologic (physical property) longitudinal change rules, i.e., different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, different shale lithologic grain interlayer interlayers, and different shale lithologic grain interlayer interlayers; the development of the top and bottom plates of the high-quality shale reservoir enables the shale gas to have a self-sealing reservoir forming characteristic; then simulating the adsorbability of the shale gas through laboratory thermal cracking to obtain a shale gas adsorbability rule, and identifying whether the shale gas has a self-sealing reservoir forming characteristic or not. And finally, measuring the distribution rule of the microscopic porosity and the pore diameter through a scanning electron microscope, judging whether the shale layer is a non-or ultra-low permeability layer under the formation temperature and pressure condition or not, and identifying whether the shale gas has the self-sealing reservoir forming characteristic or not. According to the method, the self-sealing reservoir forming of the shale gas is identified in multiple aspects, and the method provides effective technical support for evaluating the favorable layer section of the shale and is of great significance in improving the exploration and development effect of the shale gas.

The invention provides a coastal area foundation pit dewatering system and method, and belongs to the technical field of foundation pit dewatering, the coastal area foundation pit dewatering system comprises a foundation pit, a plurality of light well points, a deep tube well and an electroosmosis auxiliary module, and the light well points are annularly arranged in a shallow layer area on the periphery of the foundation pit; the deep tube well extends to a deep area from the ground; and a plurality of electro-osmosis auxiliary modules are arranged in the peripheral clay layer area of the foundation pit. The annularly-arranged light well points evenly intercept shallow underground water around the foundation pit, the deep pipe wells can rapidly reduce the deep underground water level, and the drainage problem of a low-permeability clay layer area is effectively solved through the synergistic effect of the arranged electro-osmosis auxiliary modules and the well points / pipe wells; the synchronous precipitation uniformity of the complex soil layer is improved, layered targeted precipitation design is adopted in a shallow area, a deep area and a clay layer area, and the overall precipitation efficiency is improved. According to the foundation pit dewatering system in the coastal area, the problem that in the prior art, in the environment with complex hydrogeological conditions, the dewatering efficiency of a single dewatering measure is low is solved.

The invention discloses a high-capping-index and low-permeability single coal seam construction, pressing and explosion alternate permeability increasing method, which comprises the following steps of: performing pressure relief and permeability increasing on a coal seam through large-drill-diameter extraction, hole formation through a seam penetrating machine, and changing rock stratum structures of a coal seam top and a bottom plate through hydraulic fracturing so as to increase a gas diffusion channel, during large-drill-diameter extraction, drill holes are controlled to incline upwards by 20 m and incline downwards by 15 m respectively, the trend of the left contour line and the trend of the right contour line are controlled to be 15 m respectively, one group of drill holes are constructed at the interval of 5 m, and the drill hole construction diameter is phi 133 mm; hydraulic fracturing is carried out through the large-drill-diameter layer-penetrating drill holes to respectively fracture a top plate and a bottom plate of the coal seam, damage the rock stratum structure of the top plate and the bottom plate of the coal seam, change stress distribution of the coal seam and increase gas diffusion channels; after the outburst prevention measure layer-crossing construction in the large-drill-diameter area is carried out, fixed-point hole forming is carried out on a coal seeing section according to the actual coal seeing condition of the layer-crossing drilling holes at intervals of one group of construction layer-crossing hole forming drilling holes, and hole forming phi is 500 mm. According to the method, the gas extraction effect of the low-permeability coal seam can be greatly improved, and the probability of coal and gas outburst during tunneling is reduced.

The invention discloses a low-permeability rock mass presplitting grouting long anchor cable construction method. The method comprises the steps that S1, a rock drilling roadway is excavated in the upper portion of a to-be-supported area; s2, presplitting holes are excavated from the rock drilling roadway to the lower middle section of the to-be-supported area; s3, a fan-shaped anchor cable hole is constructed in surrounding rock of the area to be supported, and an anchoring agent is installed at the bottom of the hole; s4, hollow grouting anchor cables are anchored and installed in the anchor cable holes; s5, a stop-grouting plug is installed in the anchor cable hole, and a tray and a lock of the anchor cable are installed; s6, pre-splitting blasting is conducted on the pre-splitting hole, and then a grouting hole and a stop-grouting plug are installed in the empty hole; s7, grouting holes formed in empty holes of the anchor cable hole and the pre-splitting hole are used for grouting in the holes at the same time, and then the grouting holes are blocked through screwed plugs; according to the application, the permeation range of the slurry in the rock is enlarged, so that the integrity of the rock mass is improved through grouting, and the stress state of the rock mass is improved; the grouting anchor cable construction quality of the low-permeability rock mass can be improved, and the permeation range of grout in surrounding rock is widened.

The embodiment of the invention provides a method and device for determining the petroleum migration state of tight sandstone oil accumulation, and relates to the technical field of petroleum and natural gas. The method comprises the following steps: acquiring permeability and a plurality of flow velocity and pressure gradient curves of a plurality of sandstone samples; according to the flow velocity and pressure gradient curve, the Reynolds number and friction coefficient calculation formula related to the permeability and the apparent permeability calculation formula, a Reynolds number and friction coefficient curve related to the permeability and an apparent permeability pressure gradient curve are obtained through calculation; and according to the permeability, the permeability-related Reynolds number friction coefficient curve and the apparent permeability pressure gradient curve, constructing a migration flow state change chart. According to the method, the migration flow state change plate is constructed, and the plate displays three areas where petroleum cannot be migrated, nonlinearly migrated and linearly migrated in the sandstone sample; and determining the migration state of the petroleum in the sandstone sample and the minimum permeability of the petroleum in the sandstone sample through the migration flow state change chart.

The invention provides an ultrahigh-temperature-resistant water-based drilling fluid filtrate reducer as well as a preparation method and application thereof. The filtrate reducer is obtained by copolymerization of unsaturated monomers. In the molecular structure of the filtrate reducer, the main chain is a C-C bond, the side chain is a cyclic functional group with relatively strong rigidity, an amide group with strong adsorbability and a sulfonic acid group with strong hydrophilicity, the bond energy is relatively large, and the filtrate reducer is not easy to decompose and lose efficacy in an ultrahigh-temperature and high-salt calcium environment. Due to lattice substitution, the surfaces of the clay particles are negatively charged, and the filtrate reducer is adsorbed on the surfaces of the clay particles under the action of static electricity and hydrogen bonds to form a spatial network structure of the clay particles and filtrate reducer macromolecules, so that the hydration film thickness of the clay particles, Zeta potential and repulsive force among the clay particles are increased, the clay particles are not easy to coalesce, and the viscosity of the filtrate reducer is increased. Certain dispersity is kept in the drilling fluid, and clay particles with small particle size are formed, so that a compact and low-permeability filter cake is formed under the action of pressure difference, and the filter loss of the drilling fluid is effectively reduced.

The invention provides a method for determining a nanofluid oil displacement effect of a low-permeability reservoir, and relates to the technical field of oil exploitation. The method comprises the following steps: providing a core of a low-permeability reservoir, and measuring the particle size of nanoparticles in a target nanofluid; performing high-pressure mercury injection test and nuclear magnetic resonance measurement on the rock core to respectively obtain a rock core pore throat radius-distribution frequency relation curve and a first T2 image, and performing benchmarking on the two images to obtain a pore throat radius-relaxation time relation curve; carrying out displacement experiments (oil displacement, first water displacement, nanofluid displacement and second water displacement) on the rock core, and carrying out nuclear magnetic resonance measurement to obtain T2 images; and observing or calculating the area enclosed by the curve and the relaxation time in each image, and combining with a pore throat radius-relaxation time relation curve to obtain the oil displacement effect of the nanofluid on different pores of the oil reservoir. The oil displacement effect of the nanometer system is determined according to the characteristic parameters of the reservoir core before and after the nanometer fluid is injected, and the method has important guiding significance for formulating a scheme for improving the recovery effect of the low-permeability oil reservoir.

The present application relates to the technical field of geological data processing, and more particularly to a low-permeability reservoir geological dessert prediction method and system and a medium. The method comprises the following steps: obtaining low-permeability reservoir geological data; preprocessing the low-permeability reservoir geological data to obtain standard low-permeability reservoir geological data; performing multi-dimensional feature recognition on the standard low-permeability reservoir geological data to obtain multi-dimensional geological feature data; extracting key low-permeability reservoir information from the multi-dimensional geological feature data to obtain key low-permeability reservoir information; and extracting low-permeability reservoir cores from the key low-permeability reservoir information to generate low-permeability reservoir core data. Through data processing technology, pattern recognition technology and machine learning technology, the present application realizes multi-dimensional analysis of low-permeability reservoir geological features and correlation analysis in combination with the seismic characteristics of low-permeability reservoirs, thereby improving the accuracy of low-permeability reservoir geological dessert prediction.

A conformance control method includes identifying a target location of a wellbore formed from a terranean surface to two subterranean formations that include a high permeability formation having a first permeability and a low permeability formation having a second permeability that is equal or less than one-third of the first permeability. The method includes forming a first plurality of tunnels in the high permeability formation from the wellbore; injecting, into the high permeability formation and the low permeability formation, a chemical fluid from the wellbore through the first plurality of tunnels; expanding a sweep area of the injected chemical fluid by injecting the chemical fluid into the high permeability formation through the first plurality of tunnels; forming a second plurality of tunnels in the low permeability formation from the wellbore; and increasing a contact area of an injection fluid in the low permeability formation with the second plurality of tunnels.

The invention relates to an ultralow permeability reservoir carbon dioxide actual sequestration amount accounting method which comprises the steps that a three-dimensional geologic model of carbon dioxide oil displacement and sequestration is established, the three-dimensional geologic model comprises at least one gas injection well and at least two oil production wells, and a relational expression of a simulated production gas-oil ratio and a simulated sequestration rate is obtained through numerical simulation; the simulated production gas-oil ratio is corrected through the actual average gas-oil ratio after gas injection, and a corrected simulated production gas-oil ratio and simulated storage rate relational expression is obtained; the background value of each monitoring object before the first gas injection well starts to be injected and the monitoring value of each monitoring object at the moment to be detected are obtained, and the sum of the absolute values of the difference values of the background values and the corresponding monitoring values of all the monitoring objects is the carbon dioxide leakage rate; the sum of the product of the actual carbon dioxide injection rate and the simulated sealing rate and the carbon dioxide leakage rate from the beginning of injection of the first gas injection well to the to-be-detected moment serves as the actual carbon dioxide sealing amount.

The invention discloses a coal seam tunnel permeability increasing system based on supercritical CO2-pulsed water composite injection and a permeability increasing method of the coal seam tunnel permeability increasing system, and belongs to the technical field of high-ground-stress low-permeability coal seam tunnel gas extraction permeability increasing. The system comprises a supercritical CO2 injection unit, a pulse water injection unit, an intelligent monitoring regulation and control system and a rotary spray head assembly. According to the method, a multi-fracture network is formed through high permeability of supercritical CO2, then high-frequency impact of pulse water is used for expanding fracture opening and enhancing connectivity, meanwhile, water consumption is reduced so as to reduce the water blocking effect, and the permeability increasing requirement of the high-ground-stress low-permeability coal seam can be met. According to the method, supercritical CO2 and pulse water are used for synergic permeability increasing, the permeability increasing radius is effectively enlarged, compared with traditional hydraulic fracturing, the effect is obviously improved, and the connectivity of a fracture network is high. The rotary injection of the pulse water enables the energy to be uniformly distributed, and hole wall collapse caused by excessive fracturing is avoided.

The invention discloses a bionic fracture network fracturing device for a low-permeability coal seam, and relates to the technical field of efficient exploitation of oil fields. A bionic fracture network fracturing device for a low-permeability coal seam comprises a recycling mechanism 1 and a hole sealing mechanism 2. The recycling mechanism comprises a recycling body, a signal transmission module is fixedly embedded in one side of the recycling body, a liquid injection module is fixedly embedded in the other side of the recycling body, and fixing pieces are clamped to the two ends of the recycling body respectively. A first connecting assembly used for being in butt joint with the hole sealing mechanism is arranged on the lower side of the middle of the recycling body. A rod cracking hole located between the signal transmission module and the fixing piece on the same side is formed in one side of the recycling body in a penetrating mode, and a gas hole located between the liquid injection module and the fixing piece on the same side is formed in the other side of the recycling body in a penetrating mode. A rod cracking mechanism is arranged at the rod cracking hole, and a gas mechanism is arranged at the gas hole; the filling liquid flows through the crack pipes and the branch crack holes to form the bionic cracks of the main channel and the pre-branch, so that the connectivity and the coverage range of the crack network are remarkably improved.

The invention discloses a multi-solid synergistic low-permeability barrier anti-seepage material which comprises river channel sand washing mud, fine tailing sand, bentonite, cationic guar gum and a polyacrylamide copolymer. The raw materials comprise, by mass, 50%-70% of river channel sand washing mud, 22%-35% of fine tailing sand, 6%-15% of bentonite, and 0.3%-0.5% of a cationic guar gum and polyacrylamide copolymer. The multi-solid synergistic low-permeability barrier anti-seepage material has remarkable advantages in the aspects of environmental protection, performance, application and the like, can effectively solve the problems of an existing landfill anti-seepage material, and has a good application prospect.

A method for collecting a heated fluid from a fractured subterranean formation can include removing a fluid having a liquid phase from the fractured subterranean formation through a wellbore that is in fluidic communication with the fractured subterranean formation. The method can also include collecting from the wellbore the heated fluid having a vapor phase that is expelled from a low permeability rock matrix of the fractured subterranean formation. The method can also optionally include injecting an injection fluid having the liquid phase into the low permeability rock matrix of the fractured subterranean formation through the wellbore when a parameter falls outside a range of acceptable values.

The utility model relates to the technical field of gas extraction, in particular to a soft low-permeability coal seam gas extraction drilling wall protection supporting device which comprises a supporting pipe, a threaded pipe is arranged on the inner wall of the top end of the supporting pipe, a threaded groove is formed in the inner wall of the bottom end of the supporting pipe, an anti-loosening mechanism is arranged on the threaded pipe, an annular cavity is formed in the supporting pipe, and the annular cavity is communicated with the threaded groove. A connector is formed in one side of the threaded pipe and communicates with the annular cavity, a through groove is formed between the annular cavity and the threaded groove, a sealing ring is arranged on the threaded groove, and an inflation mechanism is arranged between the annular cavity and the supporting pipe; according to the structure, the whole supporting structure can be inflated only through one connector of the threaded pipe on the uppermost supporting pipe, the inflation bag is expanded and protrudes outwards in the inflation groove to be tightly attached to the wall face of a drilled hole, strong lateral supporting force is provided, and the supporting structure is particularly suitable for being used in a soft and low-permeability coal seam and can effectively prevent the wall face of the drilled hole from collapsing.

A sheet pile embankment structure applied to a soft foundation condition is arranged on a soil layer and a soft soil layer and comprises two sheet piles, a plurality of partition plates and a plurality of anchor rods, the partition plates are arranged between the two sheet piles, connected with the two sheet piles and used for partitioning soft soil between the two sheet piles, and the anchor rods are arranged between the two sheet piles and connected with the two sheet piles. The fixing device is used for fixing two sheet piles; compared with the prior art, the soft soil is sealed through a fixed connecting structure formed among the sheet piles, the partition plates and the anchor rods, the bearing capacity of the whole structure is enhanced by means of the low permeability of the soft soil and the low compressibility under the lateral confinement condition, and the boundary condition that undrained lateral confinement is applied to the soft soil, and soft soil sedimentation is reduced.

The application provides a low-permeability stratum contaminated groundwater remediation device and method, which comprises an industrial computer, the industrial computer is used for controlling the working state of an extraction mechanism according to the information inside a pumping well, a first monitoring mechanism and a second monitoring mechanism monitor the concentration change of groundwater pollutants, and feed back the groundwater pollution condition to the industrial computer, the extraction mechanism extracts groundwater into the inside of a groundwater purifier for treatment, and a transmission mechanism changes the position of the extraction mechanism according to the distribution of the groundwater pollutants; the low-permeability stratum contaminated groundwater remediation device and method have the advantages of improving the groundwater extraction efficiency, effectively improving the extraction effect of the groundwater pollutants, and reducing the operation cost of the groundwater extraction.

The invention discloses an ultra-low / ultra-low permeability reservoir blockage determination method based on a sidetrack coring technology. The method comprises the following steps that 1, a rock core sample at a preset position is obtained; 2, recording and numbering the positions of the rock core samples; 3, the permeability and porosity of the obtained rock core samples are measured respectively, the permeability and porosity damage degree of each rock core is calculated according to the original permeability and porosity of a reservoir, and the permeability damage and the horizontal distance from the rock core to a shaft and the porosity damage and the horizontal distance from the rock core to the shaft are calculated; and 4, determining the damage space distribution condition of the rock core sample according to the data of the permeability damage degree and the porosity damage degree obtained in the step 3, and completing the determination of the blockage position of the permeability reservoir. The invention belongs to the technical field of oilfield development and detection, and solves the problems that a reservoir damage analysis method in the prior art is relatively large in limitation, cannot accurately reflect the pore damage phenomenon of an ultra-low / ultra-low permeability reservoir, cannot directly carry out experimental analysis from the microscopic level of the reservoir, and is difficult to measure the damage degree of the pore level of the reservoir.

The invention discloses a reservoir damage evaluation method suitable for a fractured bedrock gas reservoir, and the evaluation method is used for evaluating the sensitivity of an ultra-low permeability reservoir matrix core and judging the damage evaluation of a well entering fluid to a fracture. Aiming at the problem that a systematic and comprehensive damage evaluation method is not formed in a fractured bedrock gas reservoir at present, the method integrates an unsteady-state permeability determination method applied to a tight gas reservoir and a method for simulating various in-well fluid damages by preparing fractures through Brazilian splitting, and is a comprehensive evaluation method giving consideration to fracture and matrix damage evaluation. The comprehensive systematic damage evaluation of the fractured bedrock gas reservoir from the sensitivity evaluation to the in-well fluid damage is completed.

The invention discloses a flexible inner guide hollow drill rod for a low-permeability sandstone uranium mine reservoir. The flexible inner guide hollow drill rod comprises a ball head, a ball socket, an inner guide mechanism, a hollow hydraulic transducer and a drill bit, the ball heads and the ball sockets are arranged in a staggered mode in the drilling direction and connected with each other, the upper ends of the ball heads are in a tip closing-up mode so that the ball heads can be inserted into the lower ends of the ball sockets and can swing relative to the ball sockets under the action of external force, and the upper ends of the ball sockets are inserted into the lower ends of the ball heads and fixedly connected through fasteners so that the lower ball socket and the upper ball head can be assembled. The inner guide mechanism comprises an upper bearing module, a lower bearing module and a steering module located between the two bearing modules, and the upper bearing module is installed on the inner wall of the upper end of one ball socket located on the upper portion in a matched mode and can drive the ball head located on the upper portion to swing. The lower bearing module is installed on the inner wall of the upper end of the ball socket located on the lower portion in a matched mode and can drive the ball head located on the lower portion to swing. The internal guiding of the drill rod is realized through the combined action of the flexible drill rod body and the internal guiding mechanism, and the flexible steering can be realized in the drilling process.

This disclosure relates to a chemical flooding development method for highly heterogeneous, low-to-medium permeability reservoirs. The method involves preferentially injecting a first substance into the thin, poor-permeability layer of the reservoir, followed by the simultaneous injection of a second, third, and fourth substance into both the thin, poor-permeability layer and the good-permeability layer. The second substance blocks the dominant flow channels in the target layer; the third substance adjusts the liquid absorption profile of the target layer, expands the swept volume, and improves the oil displacement efficiency; and the fourth substance prevents the third substance from advancing along the dominant flow channels. Ultimately, the remaining oil in the thin, poor-permeability layer is effectively displaced, and the dominant flow channels in the good-permeability layer are blocked, forming a balanced, continuous, and effective displacement method suitable for highly heterogeneous, low-to-medium permeability reservoirs. Therefore, the chemical flooding development method provided by this invention can effectively improve the recovery rate of low-to-medium permeability reservoirs.

The application relates to an intermittent pumping sampling method for a low-permeability reservoir, which comprises the following steps: calculating the lower limit of the formation mobility of continuous pumping sampling of an ultra-low-permeability reservoir; when the mobility is less than the lower limit of the formation mobility of continuous pumping sampling, intermittent pumping is carried out; the breakthrough volume of the formation fluid is obtained, and the original invasion depth of drilling fluid is obtained through simulation inversion; according to experimental data, the initial invasion speed of mud filtrate under different original invasion depths is obtained, and the upper limit of the continuous invasion speed of mud filtrate in the pumping sampling process is determined; the numerical simulation of the key factors of intermittent pumping is carried out, intermittent pumping operation schemes under different conditions and the total operation time of the corresponding operation schemes are obtained; the optimal pressure recovery ratio is determined; the intermittent pumping operation scheme under the continuous invasion speed of mud filtrate and the optimal pressure recovery ratio and the total operation time of the operation scheme are obtained. The scheme can solve the sampling problem of the ultra-low-permeability reservoir and improve the success rate of sampling.

The invention discloses an ultra-low permeability reservoir development well type optimization method based on oil layer stacking modes. The method is specifically implemented according to the following steps that 1, the oil layer stacking modes are divided into a thick oil layer, a thin oil layer and a thin interbed according to ultra-low permeability reservoir sand body structure characteristics and reservoir physical property characteristics; 2, according to actual block reservoir parameters, oil reservoir mechanism models corresponding to three oil reservoir stacking modes of a thick oil reservoir, a thin interbed and a thin oil reservoir are established respectively; 3, a directional well, a highly-deviated well and a horizontal well are arranged in the thick oil layer oil reservoir mechanism model, the thin interbed oil reservoir mechanism model and the thin oil layer oil reservoir mechanism model respectively, and numerical simulation calculation is conducted through numerical simulation software; 4, well type optimization is conducted on the thick oil layer, the thin oil layer and the thin interbed according to calculation results of numerical simulation. The problems that in the prior art, the well type adaptability is poor, and the single well yield is low are solved.

The invention discloses a method for evaluating compressibility of a deep ultra-low permeability rock reservoir, which comprises the following steps of: analyzing a relationship between a main control factor of the compressibility of the reservoir and the fracturing difficulty of the reservoir, and determining a relational expression for representing the influence degree of the main control factor on the compressibility of the reservoir; quantitatively representing the influence degree of the main control factors on the reservoir compressibility based on the relational expression of the influence degree of each main control factor on the reservoir compressibility; and based on the influence degrees of different main control factors, evaluating the reservoir compressibility by adopting an analytic hierarchy process. According to the method disclosed by the invention, more accurate reservoir compressibility evaluation is realized by quantitatively representing the influence degree of the elastic modulus, the Poisson's ratio, the fracture toughness, the crustal stress and the natural fracture on the reservoir compressibility.

The application discloses a kind of low permeability pore-fracture multiscale structure in non-aqueous phase pollutants space-time transmission tracking method, comprising: integrated C-ERT technique simulates the long-term migration process of NAPLs in low permeability pore-fracture multiscale structure formation, real-time continuous acquisition of the resistivity space-time distribution of contaminated soil;Study the influence of NAPLs concentration on the resistivity of contaminated soil, establish the mathematical correlation model of the resistivity of contaminated soil and NAPLs concentration;Obtain the theoretical value of the space-time distribution of NAPLs concentration;Obtain the measured value of NAPLs concentration, correct mathematical correlation model, and as the quantitative evaluation basis of space-time transmission tracking process.The application can simulate the long duration, large scale migration and transformation process of NAPLs in low permeability pore-fracture multiscale structure formation, and real-time continuous tracking of pollutant trace, realize the visualization analysis of the space-time distribution of pollutant concentration, and it is of great significance to the targeted repair and management of pollutants.

The present invention belongs to the technical field of petroleum development, and specifically relates to a method for making a microscopic glass model of heterogeneous rock pores. The method includes, during the process of making an image negative film, obtaining a pore map with different permeability gradients based on a thin film image of a cast body of a core with different permeabilities to make a negative film; converting the width of the pores in the high permeability zone according to the depth requirements of the design, obtaining a contracted size, and performing photoetching on a chrome plate; etching glass to form three-dimensional channels of different depths, first etching several shallow depth zones, one part as a low permeability zone and one part as a high permeability zone; sealing the channels etched as the low permeability zone portion; and etching the channels etched as the high permeability zone portion a second time to form high permeability zone channels. The model made by the method of the present invention has three-dimensional channels of varying depths, which can simulate the actual situation of fluid migration in the channels, reflecting the difference in permeability not only in the plane but also in the vertical direction.

A conformance control method includes identifying a target location of a wellbore formed from a terranean surface to two subterranean formations that include a high permeability formation having a first permeability and a low permeability formation having a second permeability that is equal or less than one-third of the first permeability. The method includes forming a first plurality of tunnels in the high permeability formation from the wellbore; injecting, into the high permeability formation and the low permeability formation, a chemical fluid from the wellbore through the first plurality of tunnels; expanding a sweep area of the injected chemical fluid by injecting the chemical fluid into the high permeability formation through the first plurality of tunnels; forming a second plurality of tunnels in the low permeability formation from the wellbore; and increasing a contact area of an injection fluid in the low permeability formation with the second plurality of tunnels.

The invention discloses a coal seam accurate fracturing and permeability increasing method based on a low-field nuclear magnetic resonance test combined parameter well, samples of different depths of a coal seam are obtained by constructing the parameter well, and parameters such as porosity of the samples of different depths of the coal seam are obtained by testing based on a low-field nuclear magnetic resonance test technology. Then the production casing extends into the well bottom, well cementation is conducted through a well cementation truck special for an oil field, a parameter well is transformed into a fractured well, an accurate fracturing scheme is formulated according to a low-field nuclear magnetic resonance test result, the number of perforations is increased for the position with the low permeability in a reservoir, hydraulic fracturing parameters are adjusted, and therefore a complex fracture network is constructed; fracturing difficulty is reduced, coal seam permeability is effectively improved, and finally accurate permeability increasing of the regional coal seam is achieved. In addition, the low-field nuclear magnetic resonance test method provided by the invention has no requirement on the appearance of a test sample, and can effectively solve the problem that a complete sample cannot be obtained from a soft coal seam.