针对裂缝性储层应力敏感性的常规研究方法难以做到与实际相符且不能定量分析的问题,采用储层裂缝数值模拟方法,对克深气田裂缝性储层的应力敏感性进行了研究,并分析了应力敏感性的影响因素。研究结果显示:随着有效应力的增加,裂缝的孔隙度和渗透率均随之下降,表现出较强的应力敏感,且裂缝渗透率的应力敏感程度强于裂缝孔隙度,并可采用指数函数对应力敏感曲线进行拟合;储层裂缝孔渗参数的初始值越高,其应力敏感性越强,即相对高渗储层的应力敏感性要强于相对低渗储层;对于低渗透的裂缝性储层,储层岩石塑性越强其应力敏感程度越高;不同充填程度裂缝的应力敏感性由强到弱依次为未充填缝、半充填缝和全充填缝。
There are certain difficulties in practical research and quantitative analysis of stress sensitivity in fractured reservoirs usingconventional methods.The stress sensitivity and its influencing factors in fractured reservoirs are investigated by numerical simula-tion of the fractures in Kuqa depression Keshen gas field.Results show that both the porosity and permeability of fractures declinewith increasing effective stress,showing strong stress sensitivity.Fracture permeability has higher stress sensitivity than fractureporosity,and their stress sensitivity curves can be fitted using an exponential function.The reservoir with higher initial fracture per-meability has stronger stress sensitivity.That is,high-permeability reservoir has higher stress sensitivity than low-permeability res-ervoir;in the latter case,the reservoir with greater rock plasticity has higher stress sensitivity.In fractures with different extents offilling,stress sensitivity declines in the order of unfilled fracture,half-filled fracture,and full-filled fracture.