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Effect of clays, limestone and gypsum on soluble oil flooding

Conference · · Soc. Pet. Eng. AIME, Pap.; (United States)
OSTI ID:7019395
It has been reported that the mineral composition of the reservoir affects oil recovery efficiency of the soluble oil-polymer flood. This study isolates the effect of particular mineral components often present in underground porous media on the soluble oil process. Small amounts (1 to 2%) of clay, gypsum or limestone were added to a sand pack and the effect of such minerals on oil recovery was observed. Experimental results showed that the soluble oil-flooding process is sensitive to any rock minerals which dissolve or otherwise markedly increase the divalent cation concentration in interstitial water. The relatively inert substances such as limestone do not materially affect the soluble oil process; whereas, gypsum has a considerable effect, because of its higher water solubility. Clays decrease oil recovery when interstitial water has low salinity, or when the exchangeable cation is calcium. The negative action of dissolved calcium on oil recovery can be minimized by increasing the sodium concentration in the interstitial water.
Research Organization:
Union Oil Co California
OSTI ID:
7019395
Report Number(s):
CONF-7404143-
Conference Information:
Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE-4750
Country of Publication:
United States
Language:
English