In view of the difficulty of gas desorption and migration in low permeability and high gas coal seam and the low efficiency of conventional extraction, this paper takes the 112 return air crossheading of No.2 coal seam in Huangling Shuanglong Coal Mine as the object, and uses the method of coal body test, mechanism analysis and field test to study the effect of ultrasonic excitation and liquid CO2 combined fracturing to displace CH4. The results show that the 18 kW, 25 kHz ultrasonic segmented excitation combined with 7.0~7.3 MPa liquid CO2 injection can significantly expand the fracture network. After the implementation, the CH4 concentration is increased to more than 20 %, the mixed flow, CH4 purity and cumulative purity are 2.4,4.5 and 3.44 times of the original area, respectively. The efficient extraction period is about 40 days, and the effective influence range is 25 ~ 30 m. The study can provide theoretical support and technical means for CH4 efficient extraction in low permeability and high gas coal seam.
韩桂奇. 超声波激励与液态CO2联合致裂驱替煤层CH4机理及工程应用研究[J]. 煤炭与化工, 2026, 49(9): 101-107.
Han Guiqi. Study on the mechanism and engineering application of CH4 displacement in coal seam by ultrasonic excitation and liquid CO2 combined fracturing. CCI, 2026, 49(9): 101-107.
