NEW GAS CONTROL TECHNOLOGY FOR GROUND PRESSURE-RELIEF BOREHOLE IN ABANDONED COAL MINE

摘要

Provided is a new gas control technology for a ground pressure-relief borehole in an abandoned coal mine. The technology achieves the purpose of comprehensive treatment and utilization of abandoned coal mine gas by adopting the process of ground pressure-relief borehole shaft repairing, unblocking, well washing, technical reforming and fracturing, and newly drilling main and auxiliary wells on the abandoned coal mine ground. Specifically, the technology comprises the following steps: 1. repairing the ground pressure-relief borehole shaft within an original abandoned mining area to restore gas production; 2. fracturing the ground pressure-relief borehole shaft within the original mining area and non-mining area to increase gas supply； 3. selecting 3-5 boreholes as auxiliary wells (1, 2, 3, 4) among the ground pressure-relief borehole shafts within a goaf area, the mining area and the unmined area, digging a main well (5) at a suitable position, and the main and auxiliary wells (1, 2, 3, 4, 5) are communicated with each other; pumping the gas in the auxiliary well (1, 2, 3, 4) via the main well (5), and then collecting the gas into a conveying main pipe through a ground gas conveying pipeline. The method effectively achieves the purpose of comprehensive treatment of gas in an abandoned mine, and eliminates disasters caused by gas accumulation and escape from the abandoned mine.