Surface activity and thermodynamic properties of some green surfactants from wastes in formation water at reservoir conditions

In this work an attention has been paid to prepare some anionic and nonionic surfactants based on aliphatic and aromatic moieties to evaluate their application in enhanced oil recovery (EOR). The aliphatic surfactants derived from Jatropha and waste cooking oil but the aromatics derived from alkyl benzene sulfonic acid. The nonionic surfactants were prepared by tans esterification of acids with different types of poly ethylene glycols and anionic surfactants prepared by saponification. The designated formula of the aromatic surfactants was RC6H4SO3 (en)(x) OH and R phi SO3Na where aliphatic surfactants designated as RCOO(en)(n) OH and RCOONa. The structures of these surfactants were confirmed by FT-IR. The surface activity and thermodynamic properties for three surfactants groups have been investigated. The Surface and interfacial tension were measured in high salinity formation water (200,000ppm) at different temperatures (25, 35, 45 and 55 degrees C) and 1000 psi. From surface tension measurements, CMC, pi(cmc), Gamma(max), A(min), Pc-20 were calculated. The thermodynamic parameters of micellization and adsorption were also calculated. The data discussed on the basis of structural effect. The EHJ23 (RCOO(en)(23)OH) gave a high value of structural effect(22.18 KJmol(-1)) which met the most negative value of Delta G(ads) (-37.61 KJmol(-1)) . The results explained that the (Delta G(ads)) negatives values were more than the values of (Delta Delta(Gmic)), which means that surfactants prefer to adsorb at interface before forming micelles. These surfactants exhibited ultra-low interfacial tension (IFT) at 55 degrees C and 1000 psi between 8 x 10(-2) to 2 x 10(-4) mNm(-1) which gave indication that, these surfactants can be used in EOR applications.