Abstract: A karst-vuggy reservoir is serious in reservoir heterogeneity, hence to fully understand or pay more attention to its developing situation is of significance for the reservoir development. The vertical and lateral heterogeneous structural characteristics specifically appeared in a karst-vuggy reservoir are analyzed, and the major factors affecting and controlling its heterogeneity are studied, considering its specific porosity-permeability structure and correlation. In addition, a number of techniques for describing this kind of reservoir heterogeneity are evaluated, such as random simulation, fractal geometry and cloudy transformation in reservoir modeling. It is shown that random simulation play an important part in reflecting reservoir heterogeneity such as space distribution estimation of porosity, simulation of permeability value connectivity and quantitative estimation of uncertainty of carbonate reservoir, etc.; the model developed with fractal geometry is higher coincidence to real conditions than the model developed with conventional methods; while cloudy transformation technique can be used for more clearly and truly reflecting permeability and its distribution in vuggy reservoir zone.

Key words: carbonate rock, karstification, reservoir, heterogeneity, porosity, permeability, feature, evaluation