Abstract: The presence of orientational differences in reservoir rock permeability, called anisotropy, is related to the arrangement of particles that form rocks. Meanwhile, there exists asymmetry in permeability, which is, like anisotropy, related to that of particles, too. According to the basic characteristics in rock permeability , quantitative descrption methods .of these by using different permeability parameters are presented,thus providing useful basis for in-depth study of the reservoir rocks and their oil/ gas percolation.

Key words: Reservoir rock, Perneability, Anisotropy, Asymmetry, Quantitative analysis