考虑储层初始有效应力的岩石应力敏感性分析

STRESS SENSITIVITY ANALYSIS OF RESERVOIR ROCK WITH PRIMITIVE EFFECTIVE STRESS

在原始地层条件下,储层要承受上覆岩层压力和侧限压力、孔隙压力等的共同影响,这些压力等效成初始有效压力(应力)。在考虑初始有效压力情况下对岩石的应力敏感性的分析表明,储层的物性参数(如孔隙度和渗透率等)仍然随着有效压力的增加而逐渐降低,并满足负指数衰减规律。与不考虑初始有效应力相比,渗透率的降低幅度要小一些,即岩石的应力敏感性要弱一些,但更符合实际地层情况下渗透率的变化规律,因此对指导实际生产更具现实意义。

Reservoirs are influenced by incumbency rock pressure, sideways pressure and porosity pressure at primitive stratum. This stress state is called primitive effective-stress. After the primitive effective-stress be considered, the law of stress sensitivity still follow the negative exponential attenuation. Compare to no consideration of primitive effective-stress, the descend degree of permeability is more little, so the stress sensitivity is weaker. But the law can suit to the fact, and have practical meaning for actual production.