低渗透气藏水平井分段压裂分段优化方法研究

Study on Staged Optimization Method of Staged Fracturing for Horizontal Wells in Low-permeability Gas Reservoir

水平井分段压裂已成为低渗透气藏高效开发的重要方式,针对储层非均质性强及天然裂缝分布复杂导致压裂效果差的问题,采用四维影像裂缝监测技术,建立了基于测录井曲线的应力薄弱识别方法,并引入应力薄弱发育评价参数K_(tr),结合水平井段储层发育特征对分段参数进行优化,从而充分改造应力薄弱段。研究结果表明:在高于K_(tr)截取值的井段,四维影像监测出起裂的裂缝条数多于设计值,同时压裂后产能高于平均水平。因此,能够应用K_(tr)值结合水平井段储层发育特征优化水平井分段压裂间距,对改进低渗透气藏压裂段划分方法,提高改造效率与采收率具有重要作用。

The staged fracturing in horizontal wells has become an important method for efficient development of low-permeability gas reservoirs.In view of the poor fracturing effect caused by high reservoir heterogeneity and complex distribution of natural fractures,the four-dimensional imaging technology for monitoring fractures was used to establish a weak stress identification method based on logging curve,the weak-stress development evaluation parameter K_(tr)was introduced and combined with the reservoir development characteristics of horizontal well to optimize the staged parameters,so as to fully stimulate the section with weak stress.The study results show that in the well section higher than the cutoff value of K_(tr),the number of fractures detected by four-dimensional imaging was more than the design value,and the productivity after fracturing was higher than the average level.Therefore,the K_(tr)value can be used to optimize the staged fracturing interval of horizontal wells in combination with the reservoir development characteristics of the well section and to improve the effect of fracturing and stimulation.It plays an important role in improving the fracturing section division method of low-permeability gas reservoirs and improving the efficiency of stimulation and recovery.