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

Secondary recovery by miscible fluid displacement

Patent ·
OSTI ID:6705156

This is a method for improving the areal sweep efficiency of a miscible fluid displacement method of secondary recovery. A fluid, miscible with both the crude petroleum and a drive fluid, is injected into the formation and is then forced through the formation by a drive fluid. Miscible fluids are L.P.G., propane, butane, pentane, and petroleum distillates, while the driving fluid can be natural gas, methane, ethane, and mixtures of natural gas and water. A long chain polymer is added to the miscible displacement fluid to obtain favorable mobility ratios between the drive fluid, the displacement fluid, and the reservoir oil, while retaining miscibility of the fluids. The viscosity of the drive fluid is adjusted to provide a low mobility ratio between the drive and the miscible fluids. During displacement, the reservoir is kept under sufficient pressure to keep the miscible fluid in a liquid state (less than 3,000 psi). (5 claims)

Assignee:
TUL; EDB-81-025626
Patent Number(s):
US 3167118
OSTI ID:
6705156
Country of Publication:
United States
Language:
English