The presence of orientational differences in reservoir rock permeability, called anisotropy, is related to the arrangement of particles that form rocks.

• 储集层岩石的渗透率性质存在方向上的差异，此即各向异性性质，该性质与组成岩石颗粒的排列有序程度有关，排列有序程度越强，各自异性越严重；