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

Recovery of oil by low-pressure miscible gas injection

Patent ·
OSTI ID:6217856
An oil miscible gas, such as carbon dioxide, is injected into a subterranean oil reservoir to maintain a reservoir pressure near the critical pressure of the gas. Under predetermined conditions of temperature and pressure, the miscible gas-crude oil mixture exhibits a 3-phase vapor-liquid phenomena which enhances the recovery of oil from the subterranean reservoir. A miscible gas-rich liquid phase is formed between the oil-rich liquid phase and miscible gas-rich vapor phase and exhibits a density and viscosity intermediate between that of the oil and gas regions. This phenomenon creates a unique fluid distribution and mobility relationship which provides for a significant increase in the efficiency of the displacement of the oil from the gas-swept reservoir. (6 claims)
Assignee:
Cities Service Oil Co.
Patent Number(s):
US 3623552
OSTI ID:
6217856
Country of Publication:
United States
Language:
English