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

Secondary recovery method

Patent ·
OSTI ID:6678626
A method of secondary recovery of hydrocarbons involves the use of a thickened injection fluid. The fluid consists of an intimate mixture of water, hydrocarbon solvent, and colloidal silica. The fluid is miscible with hydrocarbons in the reservoir and aqueous fluids and provides a decreased mobility ratio to enhance sweep efficiency. An advantage to using the fluid is that while it is miscible with oil at the leading edge of the slug; it is also miscible with the fluid which follows it such as water. This double miscibility results in a gradual viscosity gradient at the trailing edge of the fluid slug. This viscosity gradient prevents a sharp viscosity difference and, therefore, there is little tendency for the trailing fluid to finger into the slug. (10 claims)
Assignee:
Texaco Inc.
Patent Number(s):
US 3780808
OSTI ID:
6678626
Country of Publication:
United States
Language:
English