Microemulsoes usable for the recovery of oil fields to a high temperature, containing water with high salinity, and its application

摘要

A microemulsion comprises a mixture of water containing an excess of 60 g/l of mono- and divalent salts, a hydrocarbon, an amphoteric surfactant of the formula: IMAGE wherein m is a whole number ranging from 1 to 5, inclusive, n is a whole number ranging from 1 to 22 inclusive, X- is a member selected from the group consisting of COO-, SO3 and a sulphonated ethylene polyoxide, and R1 and R2 are hydrocarbon groups containing from 1 to 22 carbon atoms and a co- surfactant comprising at least one C1 to C10 alcohol. This microemulsion may be used for recovering petroleum in beds containing water of high salinity.