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Effect of clays, limestone, and gypsum on soluble oil flooding

Journal Article · · J. Pet. Technol.; (United States)
DOI:https://doi.org/10.2118/4750-PA· OSTI ID:7301344
Clay and gypsum greatly reduce the oil recovery of the soluble-oil polymer flood, while limestone has virtually no effect. Gypsum dissolves in flooding solutions and liberates calcium ions which affect the soluble oil flood in two ways: (1) precipitate some of the petroleum sulfonates, and (2) reduce the viscosity of polyacrylamide solution, which causes an increase in mobility and reduces oil displacing capacity. Montmorillonite clays reduce oil recovery and have more effect as the water becomes less saline. Calcium clays reduce the effectiveness of the soluble oil-polymer floods by (1) adsorbing surfactant, (2) adding Ca/sup + +/ to the flooding solution by cation exchange and thereby precipitating calcium sulfonate, and (3) adsorbing polymer and increasing mobility of the polymer solution. Limestone has no appreciable effect because it is relatively insoluble in the flooding solutions.
OSTI ID:
7301344
Journal Information:
J. Pet. Technol.; (United States), Journal Name: J. Pet. Technol.; (United States) Vol. 27; ISSN JPTJA
Country of Publication:
United States
Language:
English