Patent ID: 9701893
Date: 2017-07-11
CPC Classifications: C09K,E21B

Claim:
1. A process for mineral oil extraction by means of Winsor type III microemulsion flooding, the process comprising; injecting an aqueous surfactant formulation comprising at least three ionic surfactants, for the purpose of lowering the interfacial tension between oil and water to <0.1 mN/m, through at least one injection borehole into a mineral oil deposit, and withdrawing the mineral oil from the deposit through at least one production borehole, wherein the at least three surfactants each of which are different with regard to the alkyl moiety (R where R R the at least three different ionic surfactants of the general formula (I) each respectively includes an alkyl radical having 32 carbon atoms, 34 carbon atoms and 36 carbon atoms, wherein A is ethyleneoxy, B is propyleneoxy, D is butyleneoxy, l is from 0 to 99, m is from 0 to 99, n is from 0 to 99, X is an alkyl or alkylene group having 0 to 10 carbon atoms, M Y b is 1, 2 or 3, and a is 1 or 2,