Effects of Gravity and Viscous Crossflow on Hydrocarbon Miscible Flood Performance in Heterogeneous Reservoirs

Abstract

ABSTRACT Injected solvent composition is a key parameter in the design of hydrocarbon miscible floods. Economic optimization of a field flood requires consideration of the effect of solvent composition on flood performance at the reservoir-scale. In this study, a compositional simulation approach was used to study the effects of permeability heterogeneity, fluid crossflow, and phase behavior on displacement performance in two-dimensional, finegrid (x-z) cross-sections. Results of secondary and tertiary solvent flood simulations in various rock property fields indicate that floods with solvent enrichment at or below that required for development of multicontact miscibility in one-dimensional flow can perform as well or better than floods with richer solvents. A significant change to the current practice of solvent enrichment selection is suggested based on analysis of the simulation results.