Mobilization of oil ganglia

Abstract

Abstract Following secondary recovery processes in conventional light oil reservoirs, more than half the original oil in place may remain trapped as a discontinuous phase. During the previous recovery processes these oil ganglia have been pinched off by capillary forces and remain immobile while the continuous phase which surrounds them is able to flow freely. Furthermore if a portion of this oil is mobilized in a tertiary recovery process the conditions required to apply Darcy's equation to the flow of either phase are violated. These are also problems which are encountered during in ‐ situ recovery techniques in tar sands where the mobilization of the heavy oil occurs as a discontinuous phase. In this paper the relevant flow equations are derived. Also a parameter is deduced which directly determines the criterion for mobilization.