Effects of CO2 miscible flooding on oil recovery and the alteration of rock properties in a carbonate reservoir

摘要

This study experimentally investigated the impact of CO2 miscible flooding on oil recovery and alteration of rock properties in two carbonate cores consisting of more than 98% calcite: Edwards white representing a homogenous medium mainly consisted of micropores, and Indiana limestone representing a heterogeneous medium mostly composed of macropores. Several methods were applied to investigate the alteration of rock properties by CO2-water-carbonate minerals interactions: 1) Core flooding to measure overall changes, 2) MICP and X-ray CT to analyze small pores and large pores, respectively, 3) SEM, PCM, and ICP to verify physical and chemical reactions.