processo para recuperação de óleo a partir de uma formação contendo petróleo, composição para uso na recuperação de óleo a partir de uma formação contendo petróleo e derivados sulfonado de uma ou mais olefinas internas

A process for recovering oil from an oil-bearing formation comprises introducing into said formation an aqueous composition comprising at least one sulfonated derivative of one or more internal olefins, said internal olefins being characterized by having low amounts of tri-substitution on the olefin bond, said sulfonated derivative being obtained by sulfonating a composition comprising internal olefins of the formula: R1R2C CR3R4 wherein R1, R2, R3 and R4 are the same or different and are hydrogen or straight- or branched-chain, saturated hydrocarbyl groups and the total number of carbon atoms of R1, R2, R3 and R4 is 6 to 44 with the proviso that at least about 96 mole percent of R1 and R3 are straight- or branched-chain, saturated hydrocarbyl groups and at least about 96 mole percent of R2 and R4 are hydrogen. Further provided are compositions for use in recovering oil from an oil-bearing formation which comprise the sulfonated derivatives of one or more internal olefins having low amounts of tri-substitution on the olefin bond.