State Key Lab of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University China United
Coalbed Methane Corporation Limited

为了实现成功水力压裂煤层,从而获得工业产能的目的,提出了一套针对多层叠置煤层的压裂分层决策方法,该方法以煤层压力梯度和渗透率作为刚性判别指标;以煤层裂缝延伸模拟结果为依据,建立目标函数,优选最佳射孔组合;对封隔方式适用条件进行判断,甄别出合适的压裂分层方式。此方法有效解决了煤层含气系统间的兼容性和系统内部的共享性问题。以中国西南地区某区块某井为例,压裂分层决策划分结果为:存在2个含气系统、4个渗透率差异大的小层组,并对Ab层组进行射孔位置优化,建议对4、5号煤层进行合层压裂,并使用封隔器封堵上下层,结果证明了该方法对多层叠置煤层的适用性。

In order to achieve the goal of successful hydraulic fracturing of coal seams to obtain industrial production capacity, a fracturing slicing decision method according to the multi layer overlay seams was provided and the method was based on the seam pressure gradient and the permeability as the rigid judgement index. With the simulation results of the seam crack expansion as the basis, the target function was established and the best perforation combination was optimized. A judgem ent was conducted on the applicable conditions of the packing mode and the suitable fracturing method was judged. The method could effectively solve the compatibilit y between the gas bearing system of the seam and the internal share of the system. With a mine in a block in Southwest China as a case, the fracturing slicing decision was conducted. The divided results showed that there were two gas bearing systems existed and four small seam groups with large difference of the permeability. An op timization of the perforation location was conducted on Ab seam group. A combined seam fracturing was proposed and conducted on No.4 and No. 5 seams. The packe rs were applied to seal the top seam and low seam. The application of the method showed the suitability to the multi layer overlay seams.