초록 ▼

Hydrocarbons are recovered from a subterranean hydrocarbon-bearing formation penetrated by an injection well and a production well by displacing hydrocarbons toward the production well using an aqueous drive fluid such as water or brine containing dissolved therein: (a) a small amount of a nonionic

Hydrocarbons are recovered from a subterranean hydrocarbon-bearing formation penetrated by an injection well and a production well by displacing hydrocarbons toward the production well using an aqueous drive fluid such as water or brine containing dissolved therein: (a) a small amount of a nonionic surfactant formed by reacting an alcohol having not more than 6 carbon atoms or phenol first with butylene oxide and then with ethylene oxide and (b) a small amount of an anionic sulfate or sulfonate surfactant. Optionally the drive fluid may be saturated with natural gas, nitrogen and/or carbon dioxide at the injection pressure. A polymeric thickening agent also may be included in the drive fluid, if desired.

대표청구항 ▼

A process for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation penetrated by an injection well and a production well which comprises: (A) injecting into the formation via an injection well an aqueous drive fluid comprising water or brine containing therein: (a) from about 0.

A process for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation penetrated by an injection well and a production well which comprises: (A) injecting into the formation via an injection well an aqueous drive fluid comprising water or brine containing therein: (a) from about 0.05 to about 6.0 weight percent of a nonionic surfactant of the formula: RO(R′O)m(CH2CH2O)nH wherein R is selected from the group consisting of an alkyl of 1 to 6 carbon atoms, phenyl and tolyl; R′is a 1,2- or 2,3-butylene radical; m is an integer from 1 to 40 and n is an integer of 10 or greater such that the resulting surfactant contains not less than 50 weight percent of oxyethylene units, and (b) from about 0.03 to about 5 weight percent of an anionic sulfate or sulfonate surfactant, (B) forcing the said fluid through the formation, and (c) recovering hydrocarbons through the production well.