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Title: MINERAL-SURFACTANT INTERACTIONS FOR MINIMUM REAGENTS PRECIPITATION AND ADSORPTION FOR IMPROVED OIL RECOVERY

Technical Report ·
DOI:https://doi.org/10.2172/835274· OSTI ID:835274

Significant surfactant loss by adsorption or precipitation on reservoir minerals can cause chemical flooding processes to be less than satisfactory for enhanced oil recovery. This project is aimed towards an understanding of the role of reservoir minerals and their dissolved species in chemical loss by precipitation or adsorption of surfactants/polymers in enhanced oil recovery. Emphasis will be on the type and nature of different minerals in the oil reservoirs. Macroscopic adsorption, precipitation, wettability and nanoscopic orientation/conformation studies for aggregates of various surfactant/polymer mixtures on reservoir rocks systems is planned for exploring the cause of chemical loss by means of precipitation or adsorption, and the effect of rock mineralogy on the chemical loss. During this reporting period, the minerals proposed in this study: sandstone, limestone, gypsum, kaolinite and pyrite, have been characterized to obtain their particle size distribution and surface area, which will be used in the analysis of adsorption and wettability data. The effect of surfactant mixing ratio on the adsorption of mixture of C{sub 12}-C{sub 4}-C{sub 12} Gemini surfactant (synthesized during last period) and sugar-based nonionic surfactant n-dodecyl-{beta}-D-maltoside (DM) has been studied. It was discovered that even trace amounts of Gemini in the mixture is sufficient to force significant adsorption of DM. DM adsorption on silica increased from relatively negligible levels to very high levels. It is clear form analysis of the results that desired adsorption of either surfactant component in the mixtures can be obtained by controlling the mixing ratio, the total mixture concentration, pH etc. Along with these adsorption studies, changes in mineral wettability due to the adsorption of Gemini/DM mixtures were determined under relevant conditions to identify the nano-structure of the adsorbed layers. With increasing total surfactant adsorption, the silica mineral undergoes a wettability change from hydrophilic surface to hydrophobic and then revert to hydrophilic surface. The hydrophilic-hydrophobic transition point is determined also by surfactant mixing ratio. The corresponding solution behavior of mixed systems has been studied, and interaction parameters between the component surfactants have been determined, in comparison with the surfactant interactions at solid/liquid and liquid/liquid interfaces. Mineral surface modification due to the adsorption of mixed surfactants of DM and Gemini under optimal conditions, can be employed to control the mineral wettability to facilitate oil liberation in improved oil recovery processes.

Research Organization:
Columbia University (US)
Sponsoring Organization:
(US)
DOE Contract Number:
FC26-03NT15413
OSTI ID:
835274
Resource Relation:
Other Information: PBD: 30 Oct 2004
Country of Publication:
United States
Language:
English