转向剂形成人工应力遮挡的实验研究及有限元分析

针对水力压裂过程中采用的人工应力遮挡控制缝高技术,通过室内物理模拟实验,在转向剂浓度一定的条件下考虑携带液与地层压差、渗流量、时间等因素,采用电测法对人工岩芯表面应变进行了测试;利用非线性有限元方法对裂缝尖端应力进行计算,研究了转向剂形成人工应力遮挡的作用效果。结果表明采用转向剂可以建立3~4MPa的人工应力遮档,对采用转向剂的压裂设计和施工参数提出了建议。

Experimental Study and Finite Element Analysis of Artificial Stress Barrier Formed by Diverting Agent

Aimed at hydraulic fracture height control technology by artificial stress barrier,electro-metrical method was performed for physical model in order to test surface strains of artificial rock core under a constant concentration of diverting agent and factors such as carrying fluid,strata pressure difference,seepage quantity and time etc were considered in the experiment.Stress distributions around hydraulic fracture tips were calculated by using non-linear finite element method.The effect of artificial stress barrier formed by diverting agent was also investigated.The results show that artificial stress barrier with 3~4MPa utilizing diverting agent can be set up.Hydraulic fracturing design and construction parameters are proposed in use of diverting agent.