Development And Evaluation Of Xinjiang Heavy Oil Reducing Agent

Heavy oil resource is rich in our country, and exploitation of heavy oil is significant in alleviating the shortage of thin oil resources. Heavy crude oil contains high levels of resin and asphaltene, but relatively low levels of paraffin. Because of the high viscosity, high density and poor fluidity of heavy oil, the exploitation and transportation of heavy oil has become more difficult. In addition, the general pour point depression have almost no effect on the viscosity of heavy oil. According to the separation of the four components of Tahe, the asphaltene, resin and paraffin contents are respectively23.62%,32.57%and4.57%. High content of asphaltene and resin make the density reaches0.961g/cm3, and the viscosity at40℃is up to120000mpa.s, which are typical characteristics of the heavy oil. On the basis of the literature research,and consideration of the characteristics of Tahe heavy oil, we put forward the main to break up the strong association between heavy oil molecules, the secondary is adsorption eutectic of copolymer molecular chain and paraffin, which hinder its low-temperature precipitation. In this thesis, octadecyl acrylate, styrene, maleic anhydride and acrylamide were used as raw material to synthesize three different kinds of different copolymers.We studied to the action rule between additives and heavy crude oil, thus to develop new viscosity reducer with certain application prospect.At first, the reactions condition of synthesis of octadecyl acrylate had been optimized by single factor experiments. The96%yield of the monomer can be achieved following the conditions,molar ratio of acrylic acid to octadecyl alcohol of1.2,1.2%(wt%) toluene-p-sulfonic acid,4g anhydrous magnesium sulfate,1.0%(wt%) hydro-quinol and at115℃for2h. Octadecyl acrylate (OA), styrene (St) and maleic anhydride (MA) were used as monomers to synthesize ternary polymer POMA. The optimal reaction condition is at molar ratio of5:1:1OA/MA/St,1.2%(wt%) initiator and at80℃for5h.The viscosity is reduced up to37%by using compound POMS. OA, St, MA, AM were used as monomers to synthesize ternary polymer POMA and quadripolymer POMSA in the same way. Meanwhile, we studied the effect of the factors of molecular weight of polymer, additive dosage, mixing light ratio and test temperature, on the efficacy of viscosity reduction.At last, by using IR and UV spectrum analysis, we explore the action mechanism between three different viscosity reducers and Tahe heavy oil. The viscosity reducer can form a stronger association with asphaltene and resin of heavy oil, thus the orderly layered associative state of asphaltene is broken up.