Title | Date | Subject | Description | ||
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1 | Recovery of petroleum from viscous asphaltic petroleum containing formations including tar sand deposits | 1977-08-16 | petroleum recovery; bitumen; tar sand deposits; patent; high asphaltic petroleum | Petroleum materials may be effectively recovered from subterranean, viscous, asphaltic or bituminous formations such as tar sand deposits by first injecting into the tar sand formation a paraffinic hydrocarbon at a temperature below 300.degree. F which precipitates asphaltic material from the asphal... |