关键词: 致密储层, 有效应力, 应力敏感性, 渗透率, 孔喉结构, 油田开发

Abstract: The relationship between permeability and net stress of tight reservoir was experimentally studied,and a method to evaluate permeability-stress sensitivity was established on the basis of the original net stress of reservoir rather than the low net stress.This method can correctly reflect the change of pore structure,and the quadratic polynomial curve can capture the nuances of the stress sensitivity.The permeability damage caused by the elastic and plastic distortion is permanent and irreversible.The pore structure tested by scanning electron microscope and rate-controlled mercury penetration showed that porosity was weakly affected by permeability-stress sensitivity,while the size and shape of throat determined the degree of permeability-stress sensitivity.The theoretical calculation shows that there is a cone of permeability depression near the well bottom.The stress sensitivity has some influence on oil production.

Key words: tight reservoir, net stress, stress sensitivity, permeability, pore structure, oilfield development