关键词: 钻孔间距, 瓦斯抽采, 瓦斯压力, 物理模拟, 煤层气开发

Abstract: In order to study the influence of borehole layout on gas extraction efficiency, using the self-developed multi-field coupled physical simulation test system for coalbed methane production, the physical simulation test of gas extraction under different borehole spacing conditions was carried out, and the influence of borehole spacing on gas extraction effect was discussed. The results show that in the early stage of gas extraction, the rate and quantity of gas pressure drop at each measuring point are mainly affected by the distance from the borehole center, which is basically independent of the distance between the measuring point and the borehole outlet. In the process of gas extraction, the gas pressure gradient near the borehole center was large, the gas flow velocity was large, and middle pressure line of cross-section gas pressure field was circular distribution centered on boreholes. The superposition effect of extraction between adjacent boreholes will affect the effective extraction range. The closer the distance between boreholes, the larger the effective extraction range. At the same time, the effective extraction range also increases exponentially with the extraction time.