[0004] Pan Weiyi and Lun Zengmin et al. provided a device and method for rock gas permeability measurement under high pressure in the patent "A device and method for gas permeability measurement of rock under high pressure" (application number 201010520289.1); but this device only considers If the effect of confining pressure is not considered, it is impossible to simulate the state of unequal three-dimensional stress in the actual formation and study the influence of different axial stresses and different aging effects on rock gas permeability
Rock permeability is closely related to load and time. The patent applicant and Xu Weiya et al. wrote "Experimental Research on Rheological Properties and Seepage Evolution Mechanism of Clastic Rocks Under the Coupling Action of Seepage-Stress" (Journal of Rock Mechanics and Engineering, 33(8): 1613-1625, 2014.), it is believed that loading and aging effects will cause rock permeability to change by 2-5 orders of magnitude, and it has strong directionality; in addition, this device calculates the rock gas permeability coefficient based on Darcy’s law; but Due to the high density of deep rocks, low permeability, fine channels for the flow of oil, gas and water, and high seepage resistance, the interaction force at the liquid-solid interface is significant, and there is an obvious start-up pressure for seepage, resulting in classic Darcy linear seepage. The relationship is not applicable, so this device is not suitable for gas permeability testing of deep low-permeability rocks;
[0005] Chen Yifeng and Hu Shaohua proposed a low-permeability rock transient pressure pulse permeability measurement device and measurement method in the patent "Low-permeability Rock Transient Pressure Pulse Permeability Measurement Device and Measurement Method" (application number 201310207056.X). The pressure pulse method tests the gas permeability of low-permeability rocks, but does not consider the state of three-dimensional stress in the actual formation and the influence of temperature and aging effects on the gas permeability characteristics of rocks. The gas permeability test is also not applicable during the rock aging deformation process under stress state;
[0006] Xu Weiya and Wang Wei et al. proposed in the patent "A Device and Method for Measuring Rock Gas Permeability" (Application No. 201210590766.0) to calculate the rock gas permeability by recording the axial pressure difference between the two ends of the rock sample material at different times. The device and method, the calculation method of this device is similar to the pressure pulse method, but it still does not consider the state of the actual formation three-dimensional stress and the influence of temperature and aging effect on the permeability characteristics of rock gas; As the depth increases, the temperature increases, the thermal expansion of rock skeleton particles, and the deterioration of mechanical properties. Combined with the long-term effects of gas penetration and aging, the structure will be significantly damaged, and it is easy to expand or even disintegrate, resulting in the collapse of the pore structure of tight rock reservoirs and The strength is greatly reduced, so the influence of temperature and aging is an important factor to be considered in the study of rock gas permeability
[0007] On the basis of referring to relevant domestic materials, it is believed that the original rock gas permeation testing technology has certain limitations, such as the inability to consider different stress paths, the temperature cannot be controlled, the sealing of the test device is not good, the effect of aging deformation is not considered, and data processing is not considered. Defects such as complete manualization; the inventor combined the multi-field coupling rock test method with the gas permeability measurement method and the data processing visualization method to invent a gas permeability test method in the aging deformation process of low-permeability rock under the coupling of gas and heat. The method has high accuracy, can accurately set environmental parameters such as stress, temperature and air seepage pressure, realizes data transmission and automatic processing, and outputs data and curves at the same time, improves the efficiency of data collection and processing, and ensures accuracy. The technology is the first at home and abroad, with good practicability and forward-looking