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U.S. Department of Energy
Office of Scientific and Technical Information

Flooding process using a substantially anhydrous soluble oil

Patent ·
OSTI ID:7215942

A substantially anhydrous soluble oil (4 percent water) followed by 0.01 PV fresh water (less than 1 percent TDS or 0.1 percent polyvalent ions), thickened water (Pusher 500), then brine recovered more residual oil than either the microemulsion (44.5 percent water) or the soluble oil without the fresh water slug. The soluble oil followed by fresh water forms emulsions which expand the volume of the slug, and microemulsions which increase viscosity in situ. The surfactant slug contained petroleum sulfonates, Illinois crude, butyl cellosolve, and water. Packs of Nevada sand were saturated with brine (2 percent sodium chloride, 0.5 percent calcium chloride, 0.3 percent magnesium chloride), flooded with Illinois crude (7 cp), and water flooded with brine. Alternating soluble oil and fresh water slugs recovered 88.3 percent residual oil.

Assignee:
Union Oil Co. of Calif.
Patent Number(s):
US 3500922
OSTI ID:
7215942
Country of Publication:
United States
Language:
English