A NOVEL CALCULATION METHOD FOR TIGHT SANDSTONE PERMEABILITY USING ROCK CONDUCTIVITY

摘要

The prediction of tight sandstone permeability is difficult due to the combined effects of regional tectonic setting, complex pore structure, formation anisotropy, strong heterogeneity and bound water. In order to solve this problem, this paper establishes a calculation model for the permeability of tight sandstone reservoirs from the micro-scale level, combined with the Hanai-Bruggeman equation and the Kozeny-Carman equation. The model well considers the effects of formation rock conductivity (Cs), particle conductivity (Cg), formation water conductivity (Cw) and cementation index (m) on rock permeability. The influence of rock conductivity on permeability was analyzed. The results showed that the permeability increases with the increase of rock conductivity. When the tight sandstone has a low conductivity, it has little effect on the permeability. On the contrary, the impact is greater. Finally, the model was applied to a low porosity and low permeability tight sandstone reservoir, which achieved good application results. The average absolute error of the reservoir permeability prediction was 0.035 mD. This study has certain reference value for the fine evaluation of tight sandstone reservoirs.