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

Effect of clays, limestone, and gypsum on soluble oil flooding. [Flooding solutions are sensitive to divalent cations in interstitial water]

Conference ·
OSTI ID:7215983
Laboratory studies performed on unconsolidated sandpacks showed that soluble oil flooding solutions are sensitive to divalent cations in interstitial water. Small amounts (1 to 2 percent) of clay, gypsum, or limestone were added to a sandpack and the packs were waterflooded to residual oil saturation, soluble-oil flooded, and waterflooded with one PV of Dow Pusher 700 solution. Gypsum had the largest effect in reducing recoverability because of its high water solubility. Although limestone also contains calcium ions, its effect on recoveries is much less because of its relative insolubility. Clays decrease recoverability greatly when interstitial water is fresh or when the exchangeable cation is calcium. By increasing the sodium concentration in the interstitial water, the negative effect of dissolved calcium can be minimized.
OSTI ID:
7215983
Country of Publication:
United States
Language:
English