Open Surface Flotation Method for Extracted Crude Oil.
U S Patent Number 4 402 552 1983 Sep; :
A method for the separation of extracted viscous crude oil from oil sand and oil shale consists of introducing hot water at the top surface of the reservoir while steam is injected into a gallery running through the reservoir. The hot water and steam may contain a surfactant. The buoyancy of the crude oil creates an artificial water drive so that the oil rises to the top of the reservoir. The separated oil may be removed from the reservoir and the remaining material disposed of. (See also U.S. Pat. 4,302,051, Nov. 24, 1981, Which seems to be identical to this patent.)
U.S. Patent Number 4,402,552, September 6, 1983; Chem. Abstr. 97:P130,449s