HYDROCARBON RECOVERY PROCESS.

摘要

A method for increasing the recovery of crude oil from a reservoir comprising at least one oil-bearing porous subterranean formation having a permeability of greater than 10 millidarcies wherein (a) crude oil and connate water are present within the pore space of the formation rock, and (b) the crude oil that is present in the formation has an American Petroleum Institute (API) gravity of less than 30°, a viscosity under reservoir conditions of greater than 1 centipoise, and undissolved solids suspended therein, the method comprising: (A) injecting an injection water into the formation wherein the injection water has undissolved solids suspended therein, a total dissolved solids content (TDS) of 30,000 ppm or less, and a ratio of the total multivalent cation content of the injection water to the total multivalent cation content of the connate water of less than 0.9; and (B) producing within the hydrocarbon-bearing formation an emulsion comprising a discontinuous aqueous phase and a continuous oil phase (hereinafter "water-in-oil" emulsion) wherein the total amount of undissolved solids suspended in the injection water and of undissolved solids suspended in the crude oil is sufficient for the emulsion to have an undissolved suspended solids content of at least 0.05 % by weight (0.5 kg/m3) of emulsion.