Study On The Synthesis Of Oil-displacement Surfactantpetroleum Sulfonates

In this paper petroleum sulfonates used for ASP oil recovering in Daqing Oil Field were synthesized by kettle sulphonated process with daqing oil distillates and SO₃ as raw material, the optimum synthetic conditions were studied systematically, the interfacial activity and the oil displacement abililty of the petroleum sulfonates were studied indoor. The results show: the compositon and properties of the oil distillates affect the properties of petroleum sulfonates, for the oil distillates from different devices at different time, the synthestic condition should be slightly adjusted; for the 200SN and 400SN two distillates, goal acid value of the sulphonated oils should be respectively controlled in 20³5mgNaOH/g and 40⁵5mgNaOH/g; for 200SN oil distillate, the best yield was received with SO₃/distillate is 0.10, SO₃ concentration is 6% at 55℃, and under this condition the acid value of the sulphonated oil is 32.66mgNaOH/g and the product yield is 15.32%, for 400SN oil distillate, the best yield was received with SO₃/distillate is 0.11, SO₃ concentration is 10% at 55℃, and under this condition the acid value of the sulphonated oil is 39.21mgNaOH/g and the product yield is 17.52%; petroleum sulfonates producted under optimum synthetic conditon has good interface activity, when oil sulfonates concentration is 0.05⁰.4%(wt), Na₂CO₃ concentration is 0.4 ¹.4%, HPAM concentration is 1200ppm, the interfacial tension between weak base ASP system and crude oil from the fourth oil mining factory of the daqing oil field is less than 5x10^-4mN/m, and the weak base ASP system has good interfacial tension stability for three month or more; indoor simulation displacement experiment indicated that by alternating injection way with ternary and binary slugs can make the oil recovery by 15% (OOIP) above.