Laboratory study of improving petroleum recovery by changing the wettability between the solid/liquid interface

The wettability of the solid powders (silica gel or Kaolin) was measured wi th the modified Washburn equation indicated as contact angles. The wettabil ity changes for SDBS aqueous solutions on the surface of a silica gel or Ka olin powder were studied. The average aggregation number of the micelle in SDBS aqueous solution was measured by the fluorescence quenching method. Th en the oil recovery of n-dodecane on the silica gel or the Kaolin surface w as tested. The relationship between the wettability of the powder surface, the critical micelle concentration (CMC) of SDBS aqueous solution, and the mimic oil recovery of the resident oil an time powder surface has been expl ored. It has been found that the minimum contact angle (most hydrophilic co ndition) and the maximum oil recovery occurred near the critical micelle co ncentration (CMC) of SDBS while the interfacial tension between the SDBS so lution and n-dodecane was far from ultra-low condition (less than or equal to 10(-3) mN . m(-1)).