Abstract
According to the heavy oil reservoir geology and the characteristics of heavy oil of Zhongyuan oilfield, through the orthogonal experimental design method, the optimal recipe of the titled viscosity reducer system was obtained as follows: 0.05% nonylphenol polyethylene ether NP-10+0.1%amphoteric ionic surface active agent CS-B+0.1% sodium dodecylbenzenesulfonate ABS, in other words, when the mass ratio of NP-10,CS-B and ABS was 1:2:2, the viscosity-reducing effect of the system was the best. Moreover, the effects of pH value, water content, water salinity, bivalent cation concentration, temperature, et al, on the viscosity reduction of the heavy oil were investigated. The viscosity reduction rate of the heavy oil was up to 99% when the mass ratio of the heavy oil to the viscosity reducer solution was 7:3,in addition, the system was resistant to high temperature of 110℃, and tolerant to Ca2+ and Mg2+. In a word, the viscosity reducer was suitable for the heavy oil well of Zhongyuan oilfield.