沁南区块安泽斜坡带薄煤层压裂工艺优化与应用

Fracturing process optimization and application of thin coal seam in Slope Anze Block Qinnan

针对安泽斜坡带3群煤岩物性差（平均孔隙度1．70％-4．30％，吨煤含气量6．44～20．50m^3／t），煤层分叉、变薄，采用活性水大排量压裂施工易导致裂缝高度失控，支撑剂无效支撑，压裂效果变差等问题，通过活性水携砂临界流速的论证分析，确定了不同煤层厚度、不同压裂注入方式下的临界携砂排量，并优选了支撑剂粒径和组合，优化了射孔方式。研究成果现场试验应用了4口井，其中沁17—6井产气量达1000m^3／d以上，产量比较稳定。

The 3#coal seam in Slope Anze has poor physical properties with average porosity of 1.70%-4.30% and 6.44-20.50 m^3/t gas content every tons of coal. Squeezing and splitting coal seams are encountered now and then. In view of the existing situation, fracturing operation with large capacity activated water easily lead to fracture height out of control, proppant invalid support and poor fracturing effect. The critical sand-carrying capacity under different thickness of coal steam and different injection mode of fracturing were determined by analyzing the critical velocity of active water sand-carrying, and the proppant grain size and composition were selected and perforation mode also was optimized. The research results were applied in 4 wells of the field, and got better effect, among which the gas production of Well Qinl7-6 was more than 1 000 m^3/d, and the stable output was maintained.