SURPRISING TRENDS ON TRAPPED HYDROCARBON SATURATION WITH WETTABILITY

摘要

We use a three-dimensional mixed-wet random network model representing Berea sandstone to extend our previous work on relative permeability hysteresis during wateralternate-gas (WAG) injection cycles(Suicmez et al.,2007).We compute trapped hydrocarbon saturation for the following displacement sequences: primary drainage followed by gas injection to different initial gas saturations,S_(gi),followed by water injection until all the gas and oil is trapped.We study four different wettability conditions;water-wet,weakly water-wet,weakly oil-wet and oil-wet.We demonstrate that the amount of oil and gas that is trapped shows a surprising trend with wettability which cannot be captured using previously developed empirical trapping models.