和顺区块煤层气井排采影响因素分析

结合和顺区块煤层气投产井地质条件、压裂效果及排采控制等特征,分析了影响该区煤层气排采的因素。结果表明构造复杂易造成压裂裂缝与断层沟通,干扰排采;生产煤层渗透率低、解吸压力低是该区煤层气排采的不利条件;15#煤层埋深较浅,产液量低影响煤层排水降压;压裂施工应控制裂缝形态,提高压裂效果,避开区域灰岩含水层对煤层越流补给;合理控制套压,缓慢控制流压,对扩大煤层气解吸范围,提高产气量十分重要。

Analysis of Factors Influencing Recovery of CBM Wells in Heshun Block

Taking into consideration of the geological conditions,effect of fracturing,and control of recovery the CBM wells put into operation in Heshun block,the paper analyzes factors which influence recovery of CBM in this area.The results show that the complicated tectonics can easily connect the fractures produced by stimulation with the faults,which interferes recovery of CBM;that low permeability and low desorption pressure of the productive seams are unfavorable conditions for CBM recovery in this area;that shallow burial depth of No.15 seam and low fluid yield affect dewatering of seam for pressure drop;that in operation of fracturing,attention should be paid to control the morphology of fractures in order to enhance the effect of fracturing and try to avoid recharge of water to coal seam from regional limestone aquifer;and it is very important that the casing pressure should be properly controlled and the flow pressure should be controlled slowly in order to expand the range of gas desorption and increase the gas production.