FRACTAL TEXTURE RESEARCH ON THE PORES IN RESERVOIR ROCKS AND ITS APPLICATION
He Wei and Zhong Fuxun(Geological Exploration and Development Research Institute)and He Chengzu and Feng Wenguang (Chengdu College of Technology).NATUR.GAS IND. V.20,no,2,pp.67～70,3/25/2000.(ISSN 1000 0976,In Chinese)
In the paper,a two parameter fractal geometric formula expressing pore distribution in porous media is derived according to fractal theory and a research method of analyzing pore wall roughness and the heterogeneity of pore diameter distribution is proposed through calculating pore fractal dimension by use of mercury injection data.In light of the research on low permeability reservoir deformation of the sandstone and carbonate gas reservoirs in Sichuan Basin by this method,it was found that no matter whether the carbonate rock was acidized by hydrochloric acid or the sandstone by mud acid,the capillary radii at entrance holes were obviously enlarged;however,the change in fractal dimension was different,i.e.the fractal dimension of the carbonate rock after having been acidized increased to various degrees and that of the sandstone after having been acidized had a little change or decreased to a certain degree.Therefore,the carbonate rock acidized is easy to form heterogeneous erosion channels and the sandstone acidized is more inclined to forming a homogeneous erosion.The fractal geometric research on reservoir rocks is able to become an important basis and new means of studying reservoir properties,diageneses and reservoir classification.