多分层煤层压裂起裂压力及起裂位置研究

发布时间：2018-12-15 08:16

【摘要】：针对重庆松藻矿区煤层分层多、埋深和倾角变化大,导致煤层压裂参数选择和抽采钻孔布置存在盲目性的问题,采用最大拉应力理论的断裂失效准则,通过理论分析建立了多分层煤层压裂的起裂压力计算模型,并就倾角和埋深对煤层压裂起裂压力和起裂位置影响规律进行试验研究。结果表明:煤层压裂的起裂压力在埋深相同时均不随煤层倾角的改变而改变,而在倾角相同时与煤层埋深呈线性增加关系,与理论计算的起裂压力随煤层倾角和埋深的变化规律相一致。多分层煤层压裂起裂位置均位于软分层中,近水平煤层中形成网状裂缝,无明显主裂缝存在,随倾角增大,倾斜煤层中易形成明显主裂缝,主裂缝周围网状裂缝逐渐减少。
[Abstract]:In view of the problems of coal seam stratification and great variation of buried depth and inclination in Songzao mining area in Chongqing, which lead to blindness in the selection of fracture parameters and the drilling arrangement of extraction, the fracture failure criterion based on the maximum tensile stress theory is adopted. Based on theoretical analysis, the fracture initiation pressure calculation model of multi-layered coal seam fracturing is established, and the influence of dip angle and buried depth on fracture initiation pressure and location of coal seam fracturing is studied experimentally. The results show that the fracture initiation pressure of coal seam fracturing does not change with the change of seam inclination when the depth of coal seam is the same, but it increases linearly with the depth of coal seam when the dip angle is the same. It is consistent with the theoretical calculation of the variation of the initiation pressure with the dip angle and buried depth of coal seam. The fracture initiation positions of multi-layer coal seam are all located in soft stratification, the network fracture is formed in the near horizontal coal seam, and no obvious main fracture exists. With the increase of inclination angle, the obvious main fracture is easily formed in the inclined coal seam, and the net fracture around the main fracture decreases gradually.
【作者单位】：中国煤炭科工集团重庆研究院有限公司;
【基金】：国家科技重大专项资助项目(2011ZX05065)
【分类号】：TD712.62

【参考文献】