Oil recovery process including treating permeate from a ceramic membrane to enhance oil recovery

摘要

A process for recovering oil is provided. The process entails recovering an oil-water mixture from an oil-bearing formation. Next, the process entails separating oil from the oil-water mixture and producing produced water having hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. A pre-treatment process is undertaken to remove hardness and other scale-forming compounds. This entails precipitating hardness and other scale-forming compounds. After the precipitation of hardness and other scale-forming compounds, the produced water is directed to a membrane separation unit for filtering the produced water and producing a retentate having suspended solids, hardness and other scale-forming compounds, free oil and emulsified oil. The membrane separation unit also produces a permeate stream substantially free of hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. Thereafter, the permeate stream is chemically treated to enhance the recovery of oil in the oil-bearing formation. After treating the permeate stream from the membrane separation unit, the treated permeate is injected into the oil-bearing formation.