Gas miscible displacement enhanced oil recovery. Technology status report

Technical Report · Tue Oct 01 04:00:00 EDT 1985

OSTI ID:5923738

Poor reservoir volumetric sweep efficiency is the major problem associated with gas flooding and all miscible displacements. This problem results from the channeling and viscous fingering that occur due to the large differences between viscosity or density of the displacing and displaced fluids. Simple modeling and core flooding studies indicate that breakthrough can occur at just 30% pore volume injection of gas, while field tests have shown breakthrough occurring much earlier. The differences in fluid densities lead to gravity segregation. The lower density carbon dioxide tends to override the residual fluids in the reservoir. The process would be considerably more efficient if a larger area of the reservoir could be contacted by the gas. Current research has focused on the mobility control problems of carbon dioxide in enhanced oil recovery (EOR) applications. Two mobility control methods have been investigated recently. These are the use of polymers for direct thickening of high-density carbon dioxide and mobile ''foam-like dispersions'' of carbon dioxide and aqueous surfactant. Success in the search for carbon dioxide soluble polymers has been limited. Polymers that dissolve into high-density carbon dioxide have been found, but the increase in viscosity has been far less than that required for mobility control. Further work is needed to determine if adequate polymers can be synthesized for successful direct thickening of carbon dioxide. Mobile foam-like dispersions of carbon dioxide have been investigated. This concept involves altering the flowing viscosity of the gas so that viscous fingers are suppressed, and displacement is sustained in a piston-like manner. Previously unswept regions should be contacted as well as the watered-out regions of the reservoir. Both direct and indirect research concerning mobility control are discussed in Section 3.0 of this report. 10 refs. 1 tab.

• Research Organization: USDOE Morgantown Energy Technology Center, WV
• OSTI ID: 5923738
• Report Number(s): DOE/METC-86/0225; ON: DE86001022
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ADDITIVES
BENCH-SCALE EXPERIMENTS
CARBON DIOXIDE INJECTION
COLLOIDS
CONTROL
DISPERSIONS
DRILL CORES
ENERGY SOURCES
ENHANCED RECOVERY
FIELD TESTS
FLUID INJECTION
FOAMS
FOSSIL FUELS
FUELS
MISCIBLE-PHASE DISPLACEMENT
MOBILITY
OIL WELLS
PETROLEUM
PHASE STUDIES
POLYMERS
RECOVERY
RESEARCH PROGRAMS
SURFACTANTS
SWEEP EFFICIENCY
TECHNOLOGY ASSESSMENT
TESTING
WELLS