碎软煤层条带瓦斯地面高效抽采技术研究

为了提高碎软煤层条带瓦斯抽采效率和效果,基于目前地面瓦斯抽采主要采用垂直井或从式井的方式抽采效果差、效率低的现状,通过理论和实验分析论证了穿岩层压裂改造煤储层的可行性,提出了在目标煤层顶板岩层中钻水平井,并通过垂直向下射孔以及采用泵送桥塞分段进行压裂的方式进行地面瓦斯抽采。试验结果表明:顶板分段压裂水平井单井产量高、高稳产期更长、产量衰减更慢;有效水平井段控制区域内瓦斯下降均匀,更有利于进行条带瓦斯抽采;相同投资条件下,采用水平井的方式瓦斯抽采效率和投入产出比更高。

Research and Application of High Efficiency Gas Extraction Technology in Strip Block of Broken Soft Coal Seam

Based on the current situation that the ground gas drainage mainly adopt vertical wells or cluster wells,the effect of poor drainage and low efficiency is obvious.In order to improve the gas drainage efficiency and effect of the broken soft coal seam strip,the horizontal well drilling in the roof strata of the target coal seam,and the surface gas extraction is carried out by means of vertical downward perforation and fracturing with bridge plug.The feasibility is demonstrated through a series of theoretical and experimental analyses.And the following experimental and research results were obtained.The single well of roof fracturing horizontal well has higher production,longer period of highly stable production and slower decline of production.The decrease of gas in the control area of the effective horizontal well section is more homogeneous,which is more favorable for the strip block gas drainage.The gas extraction efficiency and input-output ratio of horizontal well is higher under the same investment scale.