초록 ▼

A process for the tenside flooding of reservoirs of medium and high salinities, comprises injecting an emulsion of an oil phase, an aqueous phase, and carboxymethylated oxethylate by flooding before and/or after a solution or dispersion of carboxymethylated oxethylate. In each case, the tenside and/

A process for the tenside flooding of reservoirs of medium and high salinities, comprises injecting an emulsion of an oil phase, an aqueous phase, and carboxymethylated oxethylate by flooding before and/or after a solution or dispersion of carboxymethylated oxethylate. In each case, the tenside and/or the emulsifier is selected so that the phase inversion temperature of the system of reservoir oil/flooding water/tenside/optional additives or reservoir oil/flooding water/emulsifier/optional additives, respectively, lies about 0°to 10°C. above the reservoir temperature. This method reduces tenside retention as compared with the state of the art.

대표청구항 ▼

A method for reservoir oil extraction from an oil-bearing rock formation of medium or high salinity comprising successively injecting therein at least two tenside-containing liquids, and then recovering said reservoir oil, wherein the tenside in each case is a carboxymethylated oxethylate, and at le

A method for reservoir oil extraction from an oil-bearing rock formation of medium or high salinity comprising successively injecting therein at least two tenside-containing liquids, and then recovering said reservoir oil, wherein the tenside in each case is a carboxymethylated oxethylate, and at least one of said liquids is an emulsion comprising an oil phase, an aqueous phase, and a carboxymethylated oxethylate tenside as the emulsifier which is selected so that the phase inversion temperature of the system of (reservoir oil/flooding water/emulsifier/any injection liquid additives) lies 0°-10°C. above the reservoir temperature, and at least one of said liquids is a solution or dispersion of a carboxymethylated oxethylate tenside in flooding water, wherein this tenside is also selected so that the phase inversion temperature of the system (reservoir oil/flooding water/tenside/any additives) lies 0°-10°C. above the reservoir temperature, and wherein all of said tensides are effective amounts of a mixture of 0-90 wt.% of oxethylates of the formula R－(OC2H3(CH3))m(OC2H4)nH and 100-10 wt.% of carboxymethylated oxethylates of the formula R－(OC2H3(CH3))m(OC2H4)nOCH2COOM wherein R is a hydrocarbon aliphatic group of 6-20 carbon atoms, an alkylphenyl residue of 3-18 carbon atoms in the alkyl group, a dialkylphenyl residue of 1-18 carbon atoms per alkyl group, the total number of carbon atoms in both alkyl chains being 5-30, or a trialkylphenyl residue of 1-18 carbon atoms per alkyl chain wherein the total number of carbon atoms in the three alkyl chains is 6-40; m is 0-20; n is 1-20; M is an alkali or alkaline earth metal ion or ammonium.