47 results about "Apparent permeability" patented technology

The invention relates to a gas permeability determination method of a nano-pore-containing reservoir. The method includes the steps: simulating and calculating gas flow in a digital model matrix of arock by a lattice Boltzmann method (LBM), and counting average fluid velocity under different inlet pressure conditions mu (m / s); performing least square fitting on average fluid velocities corresponding to different inlet-outlet pressure differences by the aid of fitting target functions to obtain unknown intrinsic permeability Ko (m<2>) and a diffusion coefficient Dk (m<2> / s) of the rock; calculating a slip factor bk (Pa), and calculating gas permeability of the rock, namely, apparent permeability Ka (m<2>). The method solves the problem that the permeability of an excessively compact reservoir cannot be measured.

The invention discloses a measurement method of rock core gas logging permeability. The method comprises the following steps of inputting values of rock core diameter and length into a computing chip; putting a rack core into a rubber sleeve, and applying confining pressure by a small-sized hand-cranking hydraulic pump; pushing a piston to a minimum calibration position of an inner cavity, and closing an emptying valve; setting the moving speed of the piston, starting a piston driving device, stopping working when the piston is moved to a maximum calibration position of the inner cavity, calculating the apparent permeability of rock core gas by the computing chip, and further calculating the rock core gas logging permeability to complete first-time measurement; opening the emptying valve, and then closing the emptying valve after the pressure of the inner cavity is balanced; repeating the previous steps, moving the piston to the minimum calibration position of the inner cavity, and carrying out measurement for the second time; and calculating the average value of the twice measured values by the computing chip to obtain the final rock core gas logging permeability. According to the measurement method, the rock core gas logging permeability can be measured for two times in the back and forth movement process of the piston, so that the measurement method is high in measurement efficiency and high in measurement speed, and has an important significance for rapid evaluation of rock samples collected in the field.

The invention relates to an artificial soil layer quick infiltration system and method for removing ethinylestradiol in water with high hydraulic load, and the main structure of the system adopts an organic glass column as a carrier. Overall height of the column is 55cm, including overflow space with a height of 10 cm and dense filling of artificial mixed soil and gravel filter materials with a height of 45 cm. Fillers, from top to bottom, include a mixture of silty clay, medium-fine sand and volcanic rocks with a thickness of 15 cm, zeolite with a thickness of 25 cm, and coarse sandy gravel with a thickness of 5 cm. Endocrine disruptor ethinylestradiol can be removed from the to-be-treated water successively through the column, and through the degradation of soil natural microorganisms and the physical adsorption of the filter materials. Through the system, the removal rate of ethinylestradiol in reclaimed water is 99% or above, and the average removal rate is about 90% for high-concentration distribution water containing 10 <mu>g / L of EE2. The average of operation apparent permeability of the system is 1.26cm / s, the system is high in hydraulic load and low in site condition requirements. Plugging is an important factor affecting the application of artificial soil layer rapid infiltration system engineering. The system can operate for a long time under high hydraulic load, and can effectively remove the target pollutant EE2.

The invention discloses a method for precisely measuring a gas slippage coefficient of a low-permeability coal seam. The method comprises the steps of: acquiring initial pore average pressure and initial porosity of the coal seam according to well testing analysis data of a coal-bed gas well; drilling and sampling the coal seam, carrying out a uniaxial compression test, and measuring an elasticitymodulus and a Poisson's ratio of a coal sample; carrying out a coal sample permeability test by using a low-permeability coal seam gas slippage coefficient precise measuring device, and measuring a gas apparent permeability of the coal sample; carrying out a coal sample gas adsorption strain test by utilizing the low-permeability coal seam gas slippage coefficient precise measuring device, and measuring maximum volume strain and adsorption gas constants of the coal sample; calculating to obtain porosity and pore radius of the coal sample changing along with the average pore pressure; and calculating to obtain the coal sample gas slippage coefficient changing along with the average pore pressure. The method is convenient and reliable, easy to operate, high in precision and high in safety,realizes the precise measurement of the gas dynamic slippage coefficient in the coal-bed methane production process, and provides an important theoretical basis for precise prediction of the productivity in the coal-bed methane exploitation process.

The invention discloses a shale reservoir induced heterogeneity dynamic evolution prediction method, which corrects the shale reservoir pore cross section from non-circular pores to circular pores; uses the pore equivalent diameter to quantitatively characterize the pore size evolution; calculates The apparent permeability of different sections of shale reservoirs; the apparent permeability of shale reservoirs is calculated by using the apparent permeability of different sections and the proportion of pores in different sections; based on Darcy's law of apparent permeability, the shale The material balance equation of the reservoir; by solving the material balance equation, the relationship between the apparent permeability of the shale reservoir at different positions in the matrix and the change with time is obtained, and the change relationship is used to quantitatively characterize the response and evolution of heterogeneity in the matrix to realize Prediction of dynamic evolution of induced heterogeneity in shale reservoirs. The invention can promote the development of the induced heterogeneity dynamic evaluation technology in the shale reservoir development process of pressure relief, and contribute to the understanding of the unsteady law in the shale reservoir development process.

The present invention belongs to the technical field of unconventional oil and gas development, and relates to a method for calculating apparent permeability of porous media of shale reservoir. The method includes the steps of: S1, collecting basic parameters of shale gas reservoir, calculating to obtain a Knudsen coefficient and a contribution coefficient; S2, utilizing the Knudsen coefficient tojudge the flow state of the gas in the capillary tube, and establishing the corresponding gas mass transport equation; S3, according to the water saturation of the reservoir rock sample, determiningthe effective flow radius corresponding to the capillaries of different sizes; S4, establishing unified mass transport equation of gas in different flow states in capillary tubes; S5. according to theunified mass transport equation, calculating the apparent permeability of the capillary tube, and superposing the apparent permeabilities of the capillary tubes with different sizes to obtain the apparent permeability of the whole shale core. The method of the invention takes into account the influence of different capillary sizes, distribution frequencies and water saturation of shale, and the method provided by the invention is closer to the real situation of the reservoir and obtains more accurate data.

The invention discloses a measurement method of rock core gas logging permeability. The method comprises the following steps of inputting values of rock core diameter and length into a computing chip; putting a rack core into a rubber sleeve, and applying confining pressure by a small-sized hand-cranking hydraulic pump; pushing a piston to a minimum calibration position of an inner cavity, and closing an emptying valve; setting the moving speed of the piston, starting a piston driving device, stopping working when the piston is moved to a maximum calibration position of the inner cavity, calculating the apparent permeability of rock core gas by the computing chip, and further calculating the rock core gas logging permeability to complete first-time measurement; opening the emptying valve, and then closing the emptying valve after the pressure of the inner cavity is balanced; repeating the previous steps, moving the piston to the minimum calibration position of the inner cavity, and carrying out measurement for the second time; and calculating the average value of the twice measured values by the computing chip to obtain the final rock core gas logging permeability. According to the measurement method, the rock core gas logging permeability can be measured for two times in the back and forth movement process of the piston, so that the measurement method is high in measurement efficiency and high in measurement speed, and has an important significance for rapid evaluation of rock samples collected in the field.

The invention discloses a shale reservoir permeability prediction method based on the improved Kozeny-Carman model, which corrects the shale reservoir pore cross section from non-circular pores to circular pores; uses the pore equivalent diameter to quantitatively characterize the pore size evolution ; Determine the pore size fractal factor based on the fractal coarsening theory; calculate the capillary length and the number of pores in the preset range according to the pore size fractal factor, calculate the pore volume by using the real-time pore equivalent radius and the capillary length, and use the capillary length and the preset range The matrix volume is calculated by the number of pores, the dynamic porosity is calculated by using the pore volume and the matrix volume, and the apparent permeability of a single capillary of different sections is calculated by using the real-time equivalent pore radius. Permeability calculates the apparent permeability of shale. The invention comprehensively considers the characteristics of the shale reservoir, dynamically characterizes the porosity of the shale reservoir based on the fractal theory, and applies the dynamic porosity to the quantitative characterization of the permeability of the shale reservoir.

The invention discloses a flow state evaluation method considering multi-scale effects of shale, comprising the following steps: S1, collecting basic parameters of shale cores; S2, establishing an apparent permeability calculation model considering multi-scale effects; S3, establishing a simultaneous There are 4 kinds of seepage models, combined with related algorithms to obtain the pressure response curves of the upstream chamber and the downstream chamber; S4, using the pulse decay method to experimentally measure the pressure response curves of the upstream chamber and the downstream chamber; S5, combining the core pressure response of different development states Model, fit the experimental data to calculate the pressure response curves of the upstream chamber and downstream chamber, and calculate the core parameters. The present invention establishes four kinds of seepage models that simultaneously exist in the shale core that considers the matrix of adsorption and desorption and the matrix + natural fractures, and calculates the pressure response curves in the upper and lower chambers, the pressure response curves obtained through calculation and the pressure measured by experiments The response curves were fitted to obtain the relevant parameters and distributions of the four flow regimes in the rock.

The invention provides a method for judging whether a rock pore structure changes along with the particle size of particles, which comprises the following steps of: crushing the same rock sample step by step from coarse to fine, and obtaining particle samples in a mesh interval at each stage; the particle samples with the same mass are screened out at each stage, permeability tests under different pressures are carried out, and the apparent permeability values of the particle samples under different pressures and the permeability ratio of the particle samples at each stage are obtained; and comparing the change difference of the permeability ratios of the adjacent-level particle samples under the same pressure parameter, and identifying that the pore structure of the rock basically does not change along with the particle size or obviously changes along with the particle size. By using the judgment method provided by the invention, the change characteristic differences of the apparent permeability values of the particles with different particle sizes along with the pressure are compared to identify that the pore structure basically does not change along with the particle size and obviously changes along with the particle size, and the judgment method has the advantages of easy operation and convenience; the problem that whether pore structures of a large number of particle samples change along with particle sizes is difficult to effectively judge is solved.

The invention discloses a method and system for interpreting the apparent permeability of low-permeability reservoirs in formations. Firstly, the curve of the permeability measurement value of the test sample as a function of gas pressure is determined, and then the Knudsen number of the test sample under different pressures is determined. The curve of the permeability measurement value of the test sample changing with the gas pressure is converted into the curve of the permeability measurement value of the test sample changing with the Knudsen number, and the curve of the permeability measurement value of the test sample changing with the Knudsen number Square method data fitting, determine the intrinsic permeability of the test sample, the wall influence parameters of the test sample, and the ratio of the slip distance of the test sample to the molecular mean free path, when determining the apparent permeability of the low-permeability reservoir in the formation , using the wall influence parameter of the test sample and the ratio of the test sample’s slip distance to the molecular mean free path to correct the wall slip effect, so as to more accurately explain the apparent permeability of low-permeability reservoirs in the formation.

The invention discloses a method for dynamic prediction of shale reservoir permeability under the synergistic influence of complex mechanisms, correcting the shale reservoir pore cross section from non-circular pores to circular pores; using the pore equivalent diameter to quantitatively characterize the pore size evolution; based on The fractal coarsening theory determines the fractal factor of the pore size; according to the fractal factor of the pore size, the capillary length and the number of pores in the preset range are calculated, and the cross-sectional area of ​​the porous medium and the volume of the capillary bundle are calculated by using the real-time equivalent pore radius and the number of pores in the preset range Flow rate, using the capillary length, capillary bundle volume flow rate and porous medium cross-sectional area to calculate the apparent permeability of shale in different cross-section pores, and calculate the apparent permeability of shale according to the proportion of pores in different cross-sections and the apparent permeability of pores in different cross-sections. The invention can quantitatively characterize the influence of shale reservoirs on seepage due to complex multi-scale pores, storage methods, stress sensitivity and other characteristics, and realize effective dynamic prediction of shale reservoir permeability.