影响压裂裂缝形态的主控参数研究

Study of Main Controlling Parameter Affecting on Fracture Morphology

水力压裂技术在非常规油气田开采中得到了广泛的应用。而水力裂缝扩展行为和裂缝形态的研究仍不够完善。基于扩展有限元(XFEM)建立了裂缝扩展多孔介质流固耦合数值计算模型,考虑了裂缝起裂扩展,多孔介质流动和压裂液滤失等因素。根据某油田实际地质和施工参数对地面压力进行计算和对比。结果表明,计算得到的地面压力曲线与现场实测结果符合良好,验证了模型的准确性。采用此模型开展了不同地应力条件、压裂液粘度和不同排量,以及不同渗透率等参数对人工裂缝形态的影响研究,确定了影响裂缝形态的主控参数。

The hydraulic fracturing technology has been widely used in unconventional oil and gas exploration,while,the study of hydraulic fracture propagation behavior and fracture morphology is still not perfect. Based on extended finite element method( XFEM) the crack propagation in porous media flow solid coupling numerical model has been established,considering the extension of fracture initiation,porous media flow and fracturing fluid loss and other factors. According to the actual construction and geological parameters in an oilfield,surface pressure is calculated and compared,whose results show that the calculated surface pressure curve is in good agreement with the measured results,which verifies the accuracy of the model. The study of parameters such as different stress conditions,fracturing fluid viscosity and different displacement,and different permeability affecting on artificial fracture morphology with this model has been carried out to determine the master parameter impacting the fracture morphology.