Pei H.-H.,Petroleum Engineering College |
Zhang G.-C.,Petroleum Engineering College |
Ge J.-J.,Petroleum Engineering College |
Liu X.-L.,Petroleum Engineering College |
And 3 more authors.
Aimed at high salinity formation water and high bottom temperature in Tahe oilfield, an bis-quaternary ammonium salt surfactant DFA-12 was synthesized as viscosity reducer by the reaction of tertiary amine (RN (CH3) 2) and ethylene dibromide (Br (CH2)2).The optimal synthesis conditions were obtained as follows, the molar ratio of RN(CH3)2 to Br(CH3)2 was 2.602: 1,the reaction temperature was 90% and the reaction time was 24 h, and the purity of objective product reached to 98.53%. The results of emulsification experiments of the system obtained by mixing the super heavy crude oil (SHCO) from Tahe oilfield with the emulsifier solutions at mass ratio of 7:3,showed that DFA-12 had stronger salt tolerance than the other surfactants,which could still emulsify the SHCO in the brine of 214739.9 mg/L By Compound DFA-12 wi • th other surfactants, and the optimal formulation of the emulsifying viscosity reducer for the SHCO was determined; 0.25%DFA-12 +0.25% HES (amphoteric surfactant) +0.1% DFP (polymer). The viscosity of the SHCO is determined at 90% and the viscosity reducing rate is calculated on the basis of the viscosity of the SHCO, being of more than 98%. Source