| Description |
xi, 64 leaves : illustrations (some color) ; 29 cm |
| Summary |
"Recovering more oil from existing oil reservoirs using enhanced oil recovery methods holds the key for meeting future energy demands. Even though wettability is a cornerstone in oil recovery, few studies have focused on increasing oil recovery in sandstone reservoirs through wettability alteration. The objective of this thesis is to prove that altering the wettability of a sandstone rock to preferentially water-wet condition will reduce the remaining oil saturation and thus increase the percentage of recovered oil. Two commercial surfactants were selected after studying both the phase behavior and the interfacial properties of 30 surfactants with oil and 1.00% sodium chloride brine systems. Both surfactants then were tested for their ability to alter the wettability of sandstone rocks. This alteration was measured based on the contact angles of different surfactant solutions on oil-treated glass chips. In all cases, the surfactant solutions were able to alter the wettability of the oil-treated glass chips from weakly water-wet to strongly water-wet. The ability of both selected surfactants to increase the percentage of recovered oil then was examined using oil-treated sands. The oil recovery tests from both oil-wet and water-wet sand showed that both surfactants can change the wettability of oil-wet sand to water-wet and increase oil recovery. Both surfactants also were shown to significantly improve oil recovery from oil-wet sandstone through spontaneous imbibition. Considering that up to half of all sandstone reservoirs are possibly oil-wet, the results of this work could enhance oil recovery from oil-wet, water-flooded, mature sandstone reservoirs"--Abstract, leaf iii. |
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