Simulation test system and test method for coal stratum gas dynamic permeability improvement seepage and displacement

Abstract

The invention discloses a simulation test system and a test method for coal stratum gas dynamic permeability improvement seepage and displacement, which comprise a fluid injection system, a model sealing loading system and a data acquisition, processing and control system. The simulation test system and the test method for coal stratum gas dynamic permeability improvement seepage and displacementcan achieve the function of injecting fluid (gas, steam and liquid) into large-scale coal and rock bodies under different loads, can be used for simulating permeability improvement measures such as coal seam hydraulic fracturing, hydraulic cutting, blasting cracking and the like, can be used for simulating coal seam gas increasing measures such as gas injection, heat injection and the like, can monitor physical quantities such as fluid flow, pressure, solid stress, strain, temperature and the like in the coal and rock bodies in real time, and can find out multi-field coupling evolution rules such as a gas pressure field, a stress field, a deformation, a temperature field and the like in the fluid seepage process under the conditions of pressure bearing and pressure relief. The whole systemhas the advantages of simple structure, clear division of labor and convenient disassembly and assembly, can provide test parameters for permeability improvement and production improvement technologies such as hydraulic fracturing, hydraulic cutting, blasting cracking, gas injection, heat injection and the like, and can provide a verification platform for theoretical research.

Description

technical field [0001] The invention belongs to the technical field of scientific research of mining engineering and geotechnical engineering, and in particular relates to a simulation test system and test method for gas dynamic seepage enhancement and displacement in coal rock formations. Background technique [0002] my country is the country with the most severe coal and gas outburst in the world, and the generally low gas permeability of coal seams is one of the important reasons. At the same time, coal bed methane is also an important unconventional natural gas resource, which mainly occurs in the adsorbed state. Pore ​​surface of coal rock matrix. In order to increase the permeability of the original coal seam, artificial measures are usually taken to enhance the extraction of coal seam gas, such as hydraulic punching, hydraulic fracturing, hydraulic slotting and loose blasting. [0003] The principle of the above-mentioned anti-permeability measures is to increase coa...

AI Technical Summary

Problems solved by technology

[0011] 1. Most of the materials used in the test are prefabricated test pieces, and then put them into the model for test, which is complicated to operate;

[0012] 2. The sensors are all installed on the periphery of the test piece, and no sensors are buried inside the test piece, so it is impossible to monitor physical quantities such as gas pressure, solid stress, strain and temperature inside the coal and rock mass;

[0013] 3. The instrument can only complete one or two of the tests of dynamic permeability enhancement, seepage and medium injection displacement, and its functions are relatively single, so it cannot form a complete set of test systems;

[0014] 4. The instrument is mostly sealed with sealant, and the sealing effect is not ideal in high ground stress, high gas pressure, large deformation and other tests

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