%0 Journal Article
%A SUN Zhigang
%A ZHANG Chao
%A SUN Qiang
%T A Study on Fractal Quantitative Characterization Method of Low Permeability Sandstone Pore in DLH Oilfield
%D
%R 10.11885/j.issn.1674-5086.2020.11.04.03
%J Journal of Southwest Petroleum University(Science & Technology Edition)
%P 105-116
%V 45
%N 1
%X In view of the difficulty of conventional characterization methods to accurately characterize the complexity and irregularity of pore space distribution in low-permeability sandstone reservoirs, a fractal dimension calculation method is proposed to realize the quantitative characterization of pore characteristics of low-permeability sandstone reservoirs. Based on the analysis of the difference between different fractal dimension calculation methods, the MIFA method is preferably used to solve the fractal dimension of low permeability sandstone reservoirs (between 2.042 and 2.324), with the best correlation. The displacement pressure, average pore throat radius, coefficient of variation, and mean coefficient are determined as the comprehensive characterization parameters of the complexity and heterogeneity of reservoir pore throat distribution. Based on the solution of the fractal dimension of mercury injection at a constant rate, it is found that the heterogeneity of low-permeability sandstone reservoirs presents the following characteristics:small and medium pore throats are larger than small pore throats, and throat distribution is larger than pore distribution. There is certain correlation between the fractal dimension of low-permeability sandstone reservoirs and the experimental results of starting pressure gradient and stress sensitivity damage rate. The larger the fractal dimension, the stronger the heterogeneity of the pore throat distribution and the larger the starting pressure gradient is needed and the damage to the stress sensitivity will increase. The calculation of the fractal dimension of low-permeability sandstone reservoirs can be used for qualitative prediction and judgment of laboratory experimental results, and also as an important criterion for the application of relative permeability curves in reservoir engineering.
%U http://journal15.magtechjournal.com/Jwk_xnzk/EN/10.11885/j.issn.1674-5086.2020.11.04.03