The interaction of phase behavior and flow, in the presence of dispersive mixing, is examined for one-dimensional four-component enriched-gas displacements. Numerical and analytical solutions demonstrate that oil recovery may be substantially increased by gas enrichment above the minimum enrichment for miscibility (MME). The level of increase is dependent on the level of dispersive mixing and the size and shape of the two-phase region. A critical gas enrichment (CGE) above the MME is defined that separates the multicontact miscibility (MCM) region into two regions: MCM1, when the gas lies within the region of tie-line extensions, and MCM2, when the gas lies outside. For enrichments below the CGE (in MCM1), oil recovery can increase significantly with enrichment. Above the CGE (in MCM2), oil recovery is not as sensitive to enrichment for the cases studied. Displacements in the MCM1 region exhibit a combined condensing and vaporizing mechanism, whereas displacements in the MCM2 region are purely condensing.
All Science Journal Classification (ASJC) codes
- Energy Engineering and Power Technology
- Geotechnical Engineering and Engineering Geology