Development of oil inclusions under the action of chemical reagents on the reservoir

Abstract

Various conditions of formation of motionless closed hydrocarbon inclusions are considered: viscous instability of fluid displacement and inhomogeneous rock structure. Conditions of dynamic equilibrium of the inclusion in a water flow are given for one-dimensional and two-dimensional motion. Distributions of the oil content in inclusions of different shapes are numerically calculated. It is found that the amount of unrecovered oil depends on the ratio of the pressure gradients in the filtration flow of water pumped into the reservoir and the characteristic capillary pressure on the boundary of immiscible phases. It is demonstrated that the use of chemical reagents can substantially reduce the effect of capillary forces and promotes oil entrainment by the overall flow.