Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Method of enhanced oil recovery employing nitrogen injection

Patent ·
OSTI ID:6931189
Disclosed is a process for the recovery of oil from a subterranean oil reservoir by miscible displacement. An initial light hydrocarbon slug is injected into the reservoir at a rate which results in fingering of the hydrocarbon through the reservoir oil to produce a light hydrocarbon-reservoir oil mixture. Thereafter, a predominantly nitrogen containing gas is injected into the reservoir at a rate resulting in a flow velocity which is less than the velocity of the previously injected light hydrocarbon. Injection of the nitrogen containing gas strips the previously injected light hydrocarbon from the oil to form a transition zone of conditional miscibility. The miscible zone is then displaced through the reservoir by injection of a suitable driving agent. By injecting the light hydrocarbon slug, the path length through the reservoir needed to establish the conditionally miscible transition zone at the reservoir conditions of temperature and pressure can be materially decreased.
Assignee:
Texaco Inc.
Patent Number(s):
US 4418753
OSTI ID:
6931189
Country of Publication:
United States
Language:
English