多分层煤层渗透率及压裂钻孔位置确定

Penetration-rate characteristic of multistratum coal bed and reasonable arrangement of hydraulic fracture bores

从煤层在地质历史形成过程中所具有的多分层特点出发,论证了多分层煤层的总渗透率不仅取决于各分层渗透率的大小,还取决于分层厚度在煤层总厚度中所占的比例。进而分析得出,在采用钻孔注水压裂法提高煤层渗透率和增加瓦斯外排量时,注水压裂钻孔的合理布置位置应位于相对渗透率小、厚度相对比较大的分层中。该分析结果对预防煤与瓦斯突出及瓦斯抽放均具有现实的指导意义。

Based on the multistratum characteristic of coal bed that formed out of the coal bed formation in geologic history, the paper establishes that mutistratum coal bed's penetration-rate depends not only on penetration-rate of delamination, but also the proportion of delamination thickness in the total thickness of coal beds. The analysis concludes that the use of hydraulic fracture to increase the penetration-rate of coal bed and the gas evacuation content involves a reasonable arrangement of hydraulic fracture bores in the coal delamination of a greater thickness and a lower penetration-rate. The result presents significance to preventing coal and gas from breaking out and perfoming gas exhaust evacuation.