地应力对岩心渗透率伤害实验及机理分析

生产实际情况表明，有许多油气田对应力较为敏感。随着生产的进行，储集层压力下降，有效应力不断变化，引起油藏产能逐渐降低。为研究这一规律和变化规律，阐述了应用岩民测试有效应力对渗透率影响的实验原理，在对实验数据进行统计分析的基础上，拟合出有效应力与渗透经的函数关系（二次多项式）。应用毛细管渗流概念以有弹性厚壁筒厚理，研究了随着毛细管管壁内外压差变化时，毛细管内半径变化有其对毛细管渗流能力的影响，所得结论与实验结果一致。在实际生产中，应控制油藏压力快速大幅度下降，避免有效应力变化引起油藏渗流能力下降和减产。

Experimental and mechanism research about permeability damage with the change of stress

In practical production situation, many petroleum reservoirs are sensitive to the stress. The fluid pressure and effective stress will change in the course of production, and then it will induce the productivity decreasing. In this paper, the experimental principle of core analysis was described briefly. Based on the experimental data, the experimental results indicate that permeability will be damaged with the change of effective stress. At the experimental condition, the constructive relation about the effective stress and permeability was regressed as a quadratic equation, which was demonstrated by the thick canister elastic deformation mechanics and porous concept. Speedy and deep pressure decline should be avoided in case of the reservoir damage.