초록 ▼

A process for removing residual oil from the near wellbore area of a subterranean formation adjacent an injection well of a waterflood operation to improve water injectivity comprising injection through said well into said area seawater containing a surfactant having the formula: RO(C3H6O)7(C2H4O)2Y

A process for removing residual oil from the near wellbore area of a subterranean formation adjacent an injection well of a waterflood operation to improve water injectivity comprising injection through said well into said area seawater containing a surfactant having the formula: RO(C3H6O)7(C2H4O)2YX wherein: R is a mixture of alkyl groups containing from 12 to 15 carbon atoms, Y is sulfate group, and X is a monovalent cation. After the treatment to improve water injectivity, the formation is waterflooded.

대표청구항 ▼

A process for enhancing the injectivity of an injection well and thereby accelerating the recovery of oil by a waterflood process from an oil-bearing subterranean formation penetrated by at least one injection well and at least one production well wherein the near wellbore area of the formation pene

A process for enhancing the injectivity of an injection well and thereby accelerating the recovery of oil by a waterflood process from an oil-bearing subterranean formation penetrated by at least one injection well and at least one production well wherein the near wellbore area of the formation penetrated by the injection well has a low formation permeability to water as compared to the formation\s absolute permeability, said method comprising: (a) injecting into the formation through an injection well, seawater containing a surfactant in an amount effective to sweep the residual oil from the formation pore spaces in the near wellbore area and to thereby improve the water injectivity of said injection well, wherein the surfactant has the formula: RO(C3H6O)7(C2H4O)2YX wherein: R is a mixture of alkyl groups containing from 12 to 15 carbon atoms, Y is sulfate, X is a monovalent cation; and thereafter injecting seawater into the formation through the injection well.