A numerical study on the effect of cross-bedding heterogeneity geometry on oil recovery via condensing and vaporizing gas drive processes

This article uses compositional simulation to investigate the impact of different geometries and permeability contrasts within cross-bedded laminations on oil recovery from multicontact miscible gas injection. Each of the following was tested, keeping all other inputs unchanged: permeability contrast, laminae thickness, laminae angles, and exclusion of bottomset region. The impact of wettability is also discussed by comparison with results from the literature. All the properties investigated were found to have a significant impact on recovery: oil recovery increased with laminae thickness and decreased with the permeability contrast and laminae angle. Recovery increased when the bottomset was omitted from the model. In general, these results are consistent with findings from the literature for simulations of first contact miscible displacements and waterfloods through cross-bedded porous media. The results demonstrate that cross-bedding heterogeneities may have a significant impact on oil recovery despite their small length scale. Moreover, it is important to take alternative geometrical and flow properties of these heterogeneities into account when evaluating the range of possible outcomes from a chosen recovery scheme.