Miscible-gasflood-induced wettability alteration; Experimental observations and oil recovery implications

Journal Article · Mon Jun 01 00:00:00 EDT 1992 · SPE Formation Evaluation (Society of Petroleum Engineers); (United States)

DOI:https://doi.org/10.2118/20186-PA· OSTI ID:5158671

Yeh, S W; Ehrilch, R; Emanuel, A S ^[1]

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1. Chevron Oil Field Research Co. (US)

This paper presents visual cell and coreflood data pertaining to the influence of water saturation on miscible gasflood residual oil (water blocking). In visual cell studies, we equilibrate miscible gases and oils at reservoir conditions with an intervening water phase. We find that the solvent-induced deposition of separated solids causes initially water-wet quartz surfaces to become oil-wet. A number of miscible coreflood diplacements as high water saturation are considered, and the extent of water blocking is determined for Berea sandstone and reservoir cores. Displacements of fluid systems with wettability alteration and those of refined oil systems without wettability alteration are reported. We find that water-blocking measurements with pure hydrocarbons overestimate miscible flood S{sub or} regardless of the porous medium (Berea or reservoir sandstone or a reservoir carbonate) and the flood (CO{sub 2} or hydrocarbon miscible). We further find that water blocking is significantly more severe in Berea sandstone than in reservoir rock. We assert that water-blocking measurements with refined oil systems in Berea sandstone greatly overestimate water blocking in reservoirs, partially because refined oils cannot reproduce miscible-flood-induced wettability alteration.

• OSTI ID: 5158671
• Journal Information: SPE Formation Evaluation (Society of Petroleum Engineers); (United States), Journal Name: SPE Formation Evaluation (Society of Petroleum Engineers); (United States) Vol. 7:2; ISSN 0885-923X; ISSN SFEVE
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DATA
ENHANCED RECOVERY
FLUID INJECTION
GEOLOGIC DEPOSITS
INFORMATION
MINERAL RESOURCES
MISCIBLE-PHASE DISPLACEMENT
OIL FIELDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SATURATION
SEDIMENTARY ROCKS
WATER SATURATION
WATERFLOODING