低断裂韧性页岩压裂工艺

Researching fracturing method of shale with low fracture toughness

针对低断裂韧性深层页岩气压裂工艺针对性不强的问题,以深层低断裂韧性页岩气井CD-1HF井为例分析了压裂难点,提出了相应的压裂改造对策并进行了模拟论证,最后建立了压裂优化模型,对该井压裂工艺参数进行了优化和应用。结果表明:低密度粉陶-缝端脱砂、不同黏度液体配合造缝及交替注酸技术有利于增大改造体积,提升裂缝复杂度;采用大孔径射孔,黏度为100 mPa·s内的不同黏度压裂液组合,滑溜水在9~12 mPa·s时为主加砂阶段的压裂液,中后期注入胶液可有效提高改造体积;在注完胶液以后泵注液量分别为总设计液量的62%和73%时是中后期胶液注入的最佳时机。采用上述工艺措施该井增产效果显著。

In order to solve the problem that the fracturing technology in deep shale gas with low fracture toughness is not well targeted,this paper analyzes the fracturing difficulties with the deep low-fracture toughness shale gas well CD-1HF as an example,puts forward corresponding suggestions on how to fracture effectively and conducts simulation demonstration.Finally,the fracturing optimization model is established to optimize and apply the fracturing technology parameters in this well.The results show that the technologies of low density ceramic-joint end desamination,fracturing shale with different viscosity liquid and alternating acid injection are beneficial to enhance SRV and fracturing complexity index.The following technologies can effectively increase SRV:using large aperture perforation,combining different fracturing fluids with its viscosity less 100 mPa·s,employing 9-12 mPa·s fracturing fluid in the main sanding stage and injecting of glue fluid in the middle and later stages.The best time for the injection is when the pump volume is 62%and 73%of the total design volume respectively.The effect of increasing production of this well is remarkable by adopting the above technological measures.