摘要 |
Method for increasing recovery of crude oil from a reservoir having an oil-bearing porous subterranean formation with a permeability of greater than 10 millidarcies, the formation including rock having pores with crude oil and connate water having a multivalent cation content present within the pores. The crude oil in the formation has an API gravity of less than 30°, a viscosity greater than 1 centipoise, and undissolved solids suspended therein. Injection water having undissolved solids suspended therein, a total dissolved solids content of 30,000 ppm or less and a multivalent cation content such that a ratio of the multivalent cation content of the injection water to the multivalent cation content of the connate water is less than 0.9, is injected into the formation, to produce an emulsion within the formation. The emulsion has an undissolved suspended solids content of at least 0.05% by weight of emulsion. |