拖市天然裂缝型低渗透油田压裂工艺及机理研究

The fracturing technology and mechanism research of natural fracture and tight reservoir of Tuoshi Oilfield

采用岩石力学试验,可以求取拖市油田产层、隔层的物性参数,为压裂设计掌握基础资料。在生产中,用Kaiser效应测量对应地层的地应力大小,计算地应力剖面,是为了给压裂设计提供基础数据。同时,还要计算受地应力影响的近井摩阻、压裂液效率、裂缝闭合压力。计算结果与实验结果表明,拖市油田的水力裂缝在近井地带发生偏转,在这种情况下,裂缝的动态缝宽较小,水力压裂应以低砂比、长时间注入为原则,以便降低砂堵风险。

The physical parameter of payzone and interlayer can be calculated through rock mechanics experiment, and basic information can be grasped for hydraulic fracturing design. Measuring crustal stress of the corresponding stratum and calculating crustal stress section with Kaiser Effect in production aim at providing the basic data for hydraulic fracturing design. Meanwhile, nearby wellbore friction resistancefracturing liquid efficiency and fracture closure pressure affected by crustal stress need be calculated. The results of calculation and experiment show hydraulic fracture of Tuoshi Oilfield has become deflection at nearby wellbore zone.In the circumstance,the width of dynamic fracture is relatively small, and the hydraulic fracturing work must proceed on low sand concentration through long time injection to reduce the screen-out.