8 results about "Coal permeability" patented technology

The present invention discloses a method for predicting the in-situ coal permeability distribution characteristics based on image processing. The method includes: using the borehole drilling technology to implement horizontal drilling operations on the in-situ coal in front of the mining and excavation working face, obtaining coal samples and performing micro-disturbed cutting on the samples, scanning the cutting cross-section images of the coal samples through the digital core CT image module to obtain a two-dimensional image set, relying on the image parameter calculation module to realize the binary conversion of the original images and the calculation of parameters such as particle diameter, pore tortuosity, and surface porosity, and transmitting each parameter data set to the permeability region identification module to complete the calculation of the in-situ coal permeability and the identification and division of the low-permeability development area based on the image parameter data set. Based on this, the present invention introduces image processing technology combined with the coal permeability calculation theory to accurately describe the in-situ complex coal permeability distribution characteristics, and further realizes the accurate identification of the in-situ coal gas low-permeability area.

The invention provides a three-dimensional modeling method for correlation of coal permeability and pore fracture evolution, and relates to the technical field of three-dimensional modeling of a coal structure. Gray standardization, classification marking and spatial structure unit identification are carried out on all voxels at each moment, and voxel-level parameter statistics and geometric analysis are combined, so that the three-dimensional modeling method for correlation of coal permeability and pore fracture evolution is realized. According to the method, the porosity, the fracture width, the fracture connectivity and other structural characteristic parameters can be extracted and are dynamically paired with synchronously acquired physical field parameters, so that the physical accuracy and the time sequence response capability of the parameters are ensured, the accurate assignment of voxel-level parameters is also realized, the coal body heterogeneity and the dynamic evolution process are meticulously quantified, and the coal body quality is improved. The voxel scale permeability calculation method is adopted, the permeability value of each voxel can be calculated at each moment according to the voxel characteristic parameters and the physical field parameters, permeability distribution in a three-dimensional space is generated, and the structural evolution process of a coal rock core sample can be comprehensively captured.

This invention discloses a device and method for accurately measuring the equivalent width of pre-drainage gas in roadways. The device is placed inside a borehole along the bedding plane to measure the gas emission velocity. A curve showing the relationship between the gas emission velocity and the corresponding borehole depth is plotted, allowing for accurate measurement of the equivalent width of pre-drainage gas in the roadway. This method fully considers factors such as coal seam gas pressure, gas content, ground stress, burial depth, and coal permeability. Utilizing the positive correlation between gas emission velocity and the equivalent width of pre-drainage gas in the roadway, the method achieves higher accuracy and faster measurement speed. It also aligns with common knowledge in coal mine gas management and offers advantages such as short testing time, high accuracy, and simple operation, enabling the measurement results to guide on-site gas disaster management in coal mines.

The invention discloses a coal reservoir permeability test optimization method and system, and the method comprises the steps: carrying out the clustering analysis of coal samples of different coal orders through a K-means clustering and random forest algorithm, and constructing a permeability test database containing the permeability of different coal orders, the fracture pressure, the pore characteristics and other parameters; on the basis of a CT scanning result of the coal sample, physical characteristics such as a pore structure and fracture distribution of the lump coal are analyzed, a representative position is selected for sample preparation, and a fracture pressure interval of the sample is pre-judged according to a database; intelligently adjusting a pressurization strategy according to the pre-judgment interval, and switching to slow gradient pressurization when the pressure is close to the fracture pressure of the coal sample; and according to the measured data points, abnormal points and invalid data points in a fracture area are automatically identified and eliminated based on a random forest algorithm, representative data points are optimally selected in a permeability test stable section and a characteristic inflection point interval, and finally data constraint and fitting correction are performed through a P50 probability method. The method can improve the efficiency and accuracy of the laboratory coal permeability test.

The invention discloses a method for changing coal permeability and improving gas desorption by using sodium acetate. The method is suitable for being used in a low-permeability coal seam. Firstly, a sodium acetate solution is injected into a coal seam in a traditional drilling and hydraulic fracturing mode, and then hole sealing operation is conducted. The temperature of the sodium acetate solution is reduced through convective heat exchange between the sodium acetate solution and the coal seam, crystallization is generated, a large amount of heat is released, the released heat enables the local temperature of the coal seam to rise, coal seam cracks are expanded through the thermal expansion effect, the permeability is improved, and meanwhile temperature rise facilitates desorption of gas from the surface of the coal body; and the generated crystal can be used as a proppant to keep cracks open. The method is easy to implement, and the gas desorption capacity is improved while the permeation effect of the coal seam is changed.

The present invention provides a blowout-proof coal mine underground high-pressure water jet drilling and coal-breaking permeability enhancement device, comprising a crawler-type mobile base, a hydraulic drilling rig, a coal-blowout-proof water discharge device, a coal-water mixture separator and a control cabinet, wherein the front end of the hydraulic drilling rig is provided with a hydraulic drill rod, and the coal-blowout-proof water discharge device comprises a capsule sleeve, a liquid-filled capsule, a telescopic rubber tube, a liquid injection pipe, and a liquid injection pump; the liquid-filled capsule is connected to the liquid injection pump via the liquid injection pipe; the rear end of the hydraulic drill rod is connected to the high-pressure pump via a high-pressure water pipe, and the rear end of the high-pressure pump is connected to a water source box. The present invention can effectively avoid the occurrence of spray holes and the overflow of coal-water mixture and gas during the process of high-pressure water jet drilling and coal-breaking permeability enhancement in coal mines, thereby preventing the occurrence of safety accidents and improving the efficiency of jet coal breaking.

The present application provides a kind of coal body permeability and pore fissure evolution associated three-dimensional modeling method, it is related to coal body structure three-dimensional modeling technical field, the present application is by to each time all voxel gray standardization, classification mark and space structure unit identification, combine voxel level parameter statistics and geometric analysis, can extract porosity, fracture width and fracture connectivity and other structure characteristic parameters, and with the physical field parameter dynamic pairing of synchronous acquisition, not only guarantee the physical accuracy and time sequence response ability of parameter, also realize the accurate assignment of voxel level parameter, so that coal body heterogeneity and dynamic evolution process can be carefully quantified, using voxel scale permeability calculation method, can calculate the permeability value of each voxel according to voxel characteristic parameters and physical field parameters at each time, generate the permeability distribution in three-dimensional space, can fully capture the structural evolution process of coal core sample.

The application discloses a kind of deep in-situ coal body water lock strength testing device, including pressurized gas injection system, air-tightness detection system, vacuum pumping system, desorption testing system, water injection system, permeability testing system, data acquisition system.The application also provides a kind of deep in-situ coal body water lock strength testing device testing method and evaluation method.The application establishes in-situ coal body water lock strength experimental testing device and testing method under the condition of deep high stress, high ground temperature and high gas pressure, and proposes double evaluation indexes of coal permeability damage coefficient λ and coal gas retention coefficient η, constructs a set of water lock strength quantitative evaluation method, which can accurately evaluate the water lock strength of deep in-situ coal body after water injection, master the water lock damage law of hydraulic measures to coal reservoir, and provide basis for actual coal seam gas enhanced extraction, gas disaster control and other operation decisions.