Investigation on the Gas Drainage Effectiveness from Coal Seams by Parallel Boreholes

Gas drainage is an important technology to prevent coal and gas outburst, the drained a kind of clean energy. The pressure can characterize effectiveness. In this paper, we investigated effectiveness by pressure. Determined space shape flow field, state surrounding boreholes radial flow. According basic equations flow, discrete were achieved implicit difference scheme, then obtained boreholes. Results showed that midpoint between two holes presents highest pressure, declined from both sides. reflects in certain degree. with segmented characteristics first period decline curve form cubic curve, second straight line. When reaches value, rate had little relationship negative mainly influenced permeability coefficient. To improve effectiveness, anti-reflection measures are feasible, instead increasing Moreover, conclusion was verified field data.