90 results about "Low permeability" patented technology

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 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.

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 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.

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.

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 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 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 application relates to low permeability oil and gas reservoir oil testing layer selection method technical field, it is a kind of low permeability reservoir oil testing layer selection evaluation method, including fresh rock sample every 1 hour is carried out once nuclear magnetic resonance experiment, according to the total porosity of core just when out of cylinder and the total porosity of last nuclear magnetic resonance experiment, the content of light hydrocarbon component in total pore is calculated, light hydrocarbon component dispersion coefficient X is calculated again, with the oil testing result of oil well that has been tested and light hydrocarbon component dispersion coefficient X establish low permeability reservoir oil testing layer selection chart.The present application is advantageous in that using nuclear magnetic resonance full diameter core experiment, light hydrocarbon component dispersion coefficient is calculated, the permeability and oil-gas-bearing property of core are dynamically reflected, avoid the problem of big difference in artificial rock sample test result.Light hydrocarbon component dispersion coefficient is compared and analyzed with the oil testing result that has been tested, and low permeability reservoir oil testing layer selection chart is established, low permeability reservoir oil testing layer is guided, and oil and gas rate of oil testing is improved.

The invention discloses a CO2 mineralization sequestration and geological hydrogen synergistic enhanced mining method and a simulation experiment method, which are applied to a geological hydrogen reservoir containing ultra-basic rock, and the method comprises the following steps: screening the ultra-basic rock reservoir rich in magnesium iron minerals, and arranging a bottom injection well and a top recovery well; supercritical CO2 is injected into the bottom injection well, and fracturing is carried out to form a fracture net; a migration channel for CO2 sinking and H2 floating is established; geological hydrogen is extracted, the recovery pressure difference is regulated and controlled to limit upward flowing of CO2, and components and yield of extracted gas are monitored; carrying out CO2 mineralization storage and artificial geological hydrogen supply; and in multiple cycles, the geological hydrogen recovery rate is increased, and CO2 mineralization and storage are completed step by step. According to the method, aiming at the characteristics of low porosity and low permeability and fracture control seepage of the ultra-basic rock reservoir, a supercritical CO2 fracturing technology and CO2 displacement are adopted to improve the permeability and reaction contact area of the reservoir, the geological hydrogen recovery efficiency and the CO2 storage efficiency and economy can be synchronously improved, and cyclic synergistic enhancement of hydrogen energy development and CO2 mineralization storage is realized.

The application discloses a kind of special low permeability sandy conglomerate reservoir well bottom flow pressure level keeping prediction method, including the statistical special low permeability sandy conglomerate body oil reservoir core sample's permeability and pressure sensitivity relationship data;Calculate the ratio of the permeability of rock sample under each level net confining pressure condition and the permeability tested under initial net confining pressure condition;Draw the relationship curve of net confining pressure value and permeability change rate;Predict the permeability loss ratio of reservoir near the bottom of production well with the increase of production pressure difference;Calculate production pressure difference, compare permeability classification data, calculate the permeability reduction ratio in the range of salt well bottom and the influence on fluid production rate.The application is mainly aimed at the production characteristics of the production well of special low permeability sandy conglomerate reservoir, explains the internal cause of its change, and provides development theoretical basis;It has guiding significance for the initial development mode, method and production pressure control of special low permeability sandy conglomerate reservoir.

The application discloses a kind of low permeability reservoir underground gas storage multi-cycle injection-production condition under the prediction method of effective reservoir capacity boundary dynamic evolution, and the application is based on injection-production intensity driving seepage parameter self-adaptive evolution under the condition of low permeability reservoir underground gas storage multi-cycle strong injection and strong production, and the effective reservoir capacity boundary is dynamically predicted, to solve the systematic overestimation problem caused by parameter static, threshold effect neglect and connectivity loss in the effective reservoir capacity boundary prediction of low permeability reservoir underground gas storage under the condition of multi-cycle strong injection and strong production. Realize: the effective reservoir capacity boundary of injection stage and production stage is predicted respectively;Seepage parameter self-adaptive evolution with cycle and injection-production system intensity, not dependent on field testing / monitoring data;Through threshold-conductivity-connectivity accessibility triple criterion, the effective reservoir capacity boundary meeting engineering definition is obtained.

The invention relates to a CO2 injection and production collaborative optimization method, device and system for a low-permeability reservoir. The method comprises the steps that geological parameters of a target area and a current injection-production well pattern strategy are obtained; inputting the injection-production well network strategy into a preset pressure-deformation coupling model to obtain a pressure distribution matrix of each reservoir, a surface deformation vector diagram and a pressure value of each wellhead of the target area output by the pressure-deformation coupling model; inputting the geological parameters, the current injection-production well pattern strategy, the pressure distribution matrix of each reservoir, the surface deformation vector diagram and the pressure value of each wellhead into a BP neural network which completes training, and obtaining a prediction result output by the BP neural network; determining an optimization direction of a preset multi-target optimization model based on the prediction result; and on the basis of the optimization direction, an NSGA-II algorithm is adopted to carry out optimization solution on the multi-objective optimization model, and an optimized injection-production well pattern strategy is obtained. According to the scheme, the reasonability of the CO2 injection-production collaborative optimization scheme of the low-permeability reservoir is improved.

The invention discloses a low-permeability reservoir carbon dioxide flooding numerical simulation method based on Maxwell-Stefan cross diffusion, and belongs to the technical field of reservoir numerical simulation and recovery efficiency improvement. Comprising the following steps: establishing a mass conservation equation of each component based on an oil reservoir thermodynamic field, a rock physical property field, an effective diffusion coefficient matrix and reaction kinetic parameters; a diffusion flux item is expressed by a generalized Fick law based on a Maxwell-Stefan theory so as to describe a multi-component cross diffusion effect; a reaction source convergence item is determined by a COand crude oil reversible miscible phase kinetic model so as to describe a miscible phase and split phase dynamic process; sequentially executing a diffusion transmission step and a chemical reaction step for solving by adopting an operator splitting method to obtain an updated concentration field, and synchronously updating the thermodynamic field, the rock physical property field, the reaction kinetic parameters and the effective diffusion coefficient matrix; repeatedly iterating until each field and parameter change meet a convergence condition, and completing simulation of each chemical component concentration field; according to the method, the physical simplification defect in low-permeability simulation is overcome, and high-precision prediction of the displacement process is achieved.

The invention relates to the technical field of mine water disaster prevention and control, in particular to a low-permeability limestone proper-pressure grouting method which comprises the steps that the limestone fracture permeability grade and the karst fracture equivalent opening degree of a grouting section are determined; the duration of the low-permeability limestone grouting stage is preset, and the duration is divided into an initial-stage single-liquid-slurry grouting stage, a middle-stage switching grouting stage and a grouting ending stage; determining grouting process parameters of an initial single-slurry grouting stage; and grouting process parameters are adjusted according to the medium-term grouting switching stage or the grouting ending stage is started according to the situation. According to the low-permeability limestone proper-pressure grouting method provided by the invention, the grouting process adjusting principle is defined, the operation procedures of the initial single-liquid-slurry grouting stage, the middle-stage switching grouting stage and the grouting ending stage are particularly subdivided, the operation procedures of each grouting link are given according to conditions, the operation procedures are perfected, blind operation in the grouting process is avoided, and the grouting efficiency is improved. And the adaptation degree of the process method and the low-permeability stratum condition is improved, and balanced improvement of the grouting efficiency and the grouting quality is promoted.

The application discloses a kind of low permeability reservoir CO2 drive oil storage simulation method and system, the simulation method includes: establishing low permeability reservoir CO2 drive oil storage model;The low permeability reservoir CO2 drive oil storage model is solved, and grid pressure distribution, component concentration distribution and crude oil viscosity distribution result are obtained.Improve the recovery efficiency of low permeability reservoir, while achieving the goal of increasing CO2 storage capacity.The model considers the adsorption of CO2 on the pore surface, the dissolution of crude oil, the dissolution of formation water and the mineralization of aquifer, etc.The model also considers stress sensitivity and threshold pressure gradient to reflect the characteristics of low permeability reservoir.

The invention relates to a reservoir main control factor discrimination method based on correlation analysis and an analytic hierarchy process. The method comprises the following steps: (1) collecting and sorting multi-dimensional reservoir parameters such as reservoir thickness, gas content, mineral composition, shale content, physical property, pore throat structure and the like of a marine facies pore-rich low-permeability gas reservoir in a target area; (2) calculating a reservoir quality parameter (RQI); (3) carrying out correlation analysis on multi-dimensional data such as reservoir quality parameters (RQI) and geological influence factors; (4) obtaining a target weight by using an analytic hierarchy process in combination with a correlation analysis result; and (5) sorting the final weights of all the geological factors influencing the reservoir, wherein the maximum weight is the main control factor to be found. According to the technical scheme, objective and quantitative judgment of the main control factors of the reservoir is achieved through the steps of combining correlation analysis with the analytic hierarchy process, introducing the RQI model for weight redistribution and the like.

The present application relates to the technical field of oil reservoir fracture attribute description, and particularly relates to a fracture attribute fusion method based on fractured low-permeability oil reservoirs. The method comprises the following steps: establishing a fracture intensity model by combining well data with seismic data, establishing a fracture network model according to the fracture intensity model, obtaining a natural fracture attribute volume, fitting to obtain shear wave time difference data, first establishing a density model, a longitudinal wave model and a shear wave model, then establishing a rock mechanics parameter model, establishing an overburden pressure and pore pressure model according to the overburden pressure and the pore pressure of the overlying strata of a single well, establishing a ground stress model and simulating and calculating artificial fracture attribute data according to the rock mechanics parameter model and the overburden pressure and pore pressure model; fusing the artificial fracture attribute data to the natural fracture attribute volume, obtaining a fused fracture attribute volume and establishing a target geological model, and simulating and calculating fracturing artificial fracture parameters. The method provided by the present application fuses the fracture attributes of natural fractures and artificial fractures, and improves the description accuracy of fracture attributes.

The application discloses a coal mine low-permeability sandstone ground water plugging and water reduction method based on sealing utilization, and specifically implements the following steps: step 1, arranging a ground injection well and a pumping and observing integrated well according to parameters of a treatment area; step 2, determining a drilling structure of the injection well and the pumping and observing integrated well; step 3, preparing a calcium hydroxide aqueous solution and an industrial waste gas CO2 aqueous solution; step 4, sequentially injecting the calcium hydroxide aqueous solution and the CO2 aqueous solution into the treatment area, and adjusting injection parameters and determining an end time through monitoring results of the pumping and observing integrated well in the injection process, and ending the water plugging and water reduction work. The application solves the problems of the prior art, such as large viscosity of a cement-based grouting material, difficulty in entering low-permeability sandstone micropores, only macroscopic fissure plugging, poor plugging effect, underground water pollution caused by chemical grouting and unreasonable application of industrial waste gas CO2.

The invention provides an ultra-low permeability fault block oil reservoir energy storage fracturing development well pattern deployment method which comprises the following steps: collecting ultra-low permeability oil reservoir data, and simulating fracturing; on the basis of simulating fracturing, establishing a fracture network form index prediction model and a single well control range prediction chart; according to the fracture network form index prediction model and the single well control range prediction chart, the well spacing and the row spacing of the energy storage fracturing well network are determined. According to the method, the fracture network form index prediction model and the single well control range prediction chart are established from an ultra-low permeability reservoir block on the basis of simulated fracturing, and the well spacing and the row spacing of the energy storage fracturing well pattern can be determined by combining the fracture network form index prediction model and the single well control range prediction chart. By means of the method, energy storage fracturing development well pattern deployment can be guided, and efficient development of ultra-low permeability oil reservoirs is facilitated.

The invention relates to a method for arranging distributed optical fiber sensors and grouting and sealing holes in a low-permeability rock stratum, which comprises the following steps of: arranging a plurality of directional drill sites in a panel roadway of a target rock stratum, and horizontally constructing a plurality of directional drill holes towards the target rock stratum in each directional drill site; the distributed multi-parameter composite optical fiber sensors are fixed to the grouting pipes, and then the grouting pipes and the distributed multi-parameter composite optical fiber sensors are arranged in all the directional drill holes; and grouting is conducted in each directional drill hole in a segmented mode, and the slurry is solidified. According to the invention, high-precision multi-parameter measurement of a plurality of monitoring points in a long-distance wide range can be realized, more continuous and accurate stress distribution information can be provided, continuous and accurate monitoring of safe and efficient mining of complex phosphorite bodies is realized, real-time data support is provided for safe production of mines, potential geological disaster risks are early warned in time, and the safety of the mines is improved. And life safety of miners and mine production safety are guaranteed.

The invention relates to an ultra-low permeability reservoir water drive displacement boundary calculation method. The method comprises the steps that S1, the permeability K of a plurality of rock cores is obtained; s2, establishing a conversion model of core nuclear magnetic resonance relaxation time and pore throat radius r; s3, according to the pore throat radius r and the cumulative distribution frequency thereof, calculating the average pore throat radius of the rock core and a variable coefficient Dr; s4, acquiring displacement boundaries of a plurality of rock cores; and S5, establishing a core displacement boundary mathematical model, and calculating the displacement boundary of the ultra-low permeability reservoir water-flooding development through the model. According to the characteristics of the ultra-low permeability reservoir, the displacement boundary model is established by integrating the macroscopic physical property parameters and the microcosmic pore throat characteristic parameters, the displacement boundary of ultra-low permeability reservoir water drive development can be effectively predicted, selection of ultra-low permeability reservoir development modes is effectively guided, and ultra-low permeability reservoir scale benefit development is supported.

The invention discloses a double-vacuum degassing sample tube and a using method thereof, and relates to the technical field of sample analysis experiment equipment.The double-vacuum degassing sample tube comprises a pit furnace, an outer tube, an inner tube, a three-way tube, a tube penetrating connector, a first sealing connector and a second sealing connector, the outer tube is detachably arranged in the pit furnace, and the three-way tube is arranged at the upper end of the outer tube in a sleeving mode; a pipe penetrating connector is detachably arranged at the upper end of the three-way pipe, an inner pipe is arranged in the pipe penetrating connector in a penetrating mode, a gap is reserved between the outer wall of the inner pipe and the inner wall of the outer pipe, and the inner pipe and the three-way pipe are movably arranged in a penetrating mode. The device has the advantages of low permeability, low cost and long-term airtight stability, can meet the high-precision gas analysis requirements of earth deep rocks, moon samples and the like, and is compact in structure, economical in cost, simple and convenient to operate, small in size and wide in applicable experiment range and variety.

The invention provides an underground coal mine broken soft low permeability coal seam integrated directional drilling, punching, discharging and protecting machine tool and an exploring tube. A linear motor is installed at the rear end of a flow guide positioning seat, a set of flow passing holes penetrating in the radial direction are machined in the side wall of the flow guide positioning seat, and a flow limiting ring is installed at the position, close to the front end, in the flow guide positioning seat; the linear motor is connected with a reciprocating shaft, the reciprocating shaft extends into the flow guide positioning seat and is connected with a flow dividing seat in front, the front end of the flow dividing seat is coaxially connected with a central flow passage opening and closing flexible ejector rod, and the central flow passage opening and closing flexible ejector rod can extend out of a central through hole of the flow limiting ring; the linear motor drives the reciprocating shaft to drive the flow dividing base and the center flow passing channel to be opened and closed, the flexible ejector rod reciprocates front and back in the axial direction to switch the flow passing channel, and switching of the three working states of directional drilling, hydraulic punching and powerful deslagging is achieved. According to the method, the drilling efficiency, the drilling safety, the coverage range and the gas extraction effect of the broken and soft low-permeability coal seam gas extraction directional drilling are improved under the condition that a drilling tool is not lifted and replaced.

The application discloses a kind of suitable for low permeability sandstone type uranium deposit in-situ leaching well distribution method, belong to sandstone uranium deposit in-situ leaching mining technical field, first target mining area is geologically surveyed, and the spatial distribution range of ore-bearing layer is defined, then according to the main ore layer horizontal distribution range arrangement horseshoe horizontal well, and in horizontal well drop explosive implementation blasting, improve the permeability of ore bed, according to the impact fracturing range radius design horizontal well spacing and charge package installation interval, complete horizontal well well flushing, between horizontal well arrangement straight well, horizontal well injection, straight well pumping, straight well interval is most widely based on optimization design of leaching range.The application applies horseshoe well technology to low permeability sandstone uranium deposit in-situ leaching, and the horizontal section of horseshoe well is mainly used for blasting permeability, and injection leaching liquid, and straight well is used for extracting leaching liquid, through the reasonable arrangement of horseshoe well and straight well pumping injection well network, to improve the mining efficiency and recovery of uranium resources.

The present application relates to a low permeability reservoir near wellbore area effective cleanout time calculation method, and belongs to the technical field of oil and gas exploitation. The low permeability reservoir near wellbore area effective cleanout time calculation method disclosed by the present application comprises the following steps: obtaining the original formation pressure, formation volume density and permeability of a target formation; determining the minimum production pressure difference required to overcome the flow resistance of the near wellbore pollution zone based on the permeability; determining the maximum production pressure difference based on the positive correlation between the rock skeleton strength and the formation volume density; determining the reasonable production pressure difference of the oil well; keeping the gas well producing at a constant reasonable production pressure difference to obtain production data; drawing a relationship graph between the cumulative total liquid production and the production time and a two-dimensional right-angle Cartesian coordinate graph based on the production data; determining the cumulative liquid production required for effective well cleanout; and determining the effective cleanout time of the low permeability reservoir near wellbore area. The present application is more in line with the actual situation of the formation, and can provide theoretical support for determining the effective cleanout operation time of the reservoir.