Study On Synthesis And Viscosity Reducing Mechanism Of Viscosity Reducer For High Wax And High Viscosity Crude Oil

China's unconventional crude oil such as oil with high wax and high viscosity has become an important strategic energy reserve with a large amount of conventional crude oil been mined and consumed,which is attributed to the rapid development of China's social economy and the large consumption of petroleum products.However,characteristics of high viscosity and density,and poor mobility of unconventional crude oil seriously impede its smooth exploitation and effective use.As a result,research on heavy oil viscosity reducer is of great significance.In this paper,high wax crude oil of Daqing and high viscosity oil of Xinjiang and Shengli is the research objectives.Based on the summary of mechanism of action,the exploration of molecular structure,and the analysis of the physical and chemical properties of oil samples,high wax crude oil viscosity reducing agent of SOMN and high viscosity crude oil viscosity reducing agent of SMN were designed and synthesized.SOMN was synthesized by Nonylphenol polyoxyethylene ether esterifying with polymer of Octadecyl acrylate-?-Octadecene-Maleic anhydride,and SMN was synthesized by Nonylphenol polyoxyethylene ether esterifying with polymer of Styrene-Maleic anhydride.Effect on the viscosity reduction performance of their synthetic conditions were studied,such as ratio of polymerization monomers,amount of initiator BPO,reaction temperature,and reaction time.Both of SOMN and SMN were characterized and analysed by IR.Both of them got good viscosity reduction effect: at the test temperature of 35?,viscosity reduction rate of SOMN reached to 64.8% dosed with 0.6%(w/w);at the test temperature of 50?,viscosity reduction rate of SMN reached to 68.5% dosed with 0.8%(w/w).In this paper,the mechanism of SOMN acting with wax was determined by methods of viscosity-temperature curve which reflected the thermosensitivity of oil,and microscopic observation of the changes of shape,size and morphology of paraffin crystals.The mechanism of SOMN was determined that the precipitation,induced by SOMN,of wax was in the formation of a large number of highly dispersed needle-like wax crystals,and the formation of the three-dimensional network structure formed by the interconnection of wax crystals was prevented by the steric hindrance effect,formed by SOMN,on the surface of wax crystals.The mechanism of SMN acting with asphaltenes was determined by methods of viscositytemperature curve which reflected the thermosensitivity of oil,the dispersing mechanism of SMN working on the overlaying structure of asphaltenes was determined by methods of ultraviolet-visible spectral analysis,and microscopic and scanning electron microscopic observation of asphaltenes,and the method of resin-asphaltene adsorption curve determined that SMN had the effect of increasing the contact area between asphaltenes and resins and enhancing the effect of solvent dispersion of resins on asphaltenes.