Synthesis And Properties Of Pour-point Depressant For High-wax And High-viscosity Crude Oil

With the growing demand for oil in the world, effectively utilizing high-wax and high-viscosity crude oil becomes more and more important. In the late period of oilfield exploitation nowadays, high-wax and high-viscosity crude oil covers a larger proportion, which makes it important as well. This sort of oil is high-wax and high-viscosity, therefore its application in industry is limited. It follows that decreasing condensation point and viscosity of high-wax and high-viscosity crude oil out of industry, forms the difficulty and hot issue in the field of chemical research on oilfield.The new terpolymer poly(1-vinylimidazole-2- acrylamide-2-methyl propane sulfonic-octadecyl acrylate) (PVAS), composed of imidazole ring, sulfonic acid group and ester group, was synthesized by the method of dispersion copolymerization with using polyvinylpylrrolidone (PVP) as the dispersant and ethanol as the dispersion medium. The polymer was characterized by Fourier transform infrared spectroscopy (FTIR), H nuclear magnetic resonance (HNMR), thermal weight loss (TGA) and dynamic light scattering (DLS). Pour point depression of the high-wax and high-viscosity crude oil was measured by differential scanning calorimetry (DSC) and oil solidifying point tester. Furthermore, the best ratio of monomer, reaction temperature, reaction time and dosage of initiator were determined through the orthogonal test. The results indicated that the optimal conditions affecting the magnitude of pour point depression was that the amount of the PPD taken was 600ppm and the heated temperature was 80℃. Then the new functional polymer which derived from mixed imidazole ring, sulfonic acid group and ester group was synthesized by the solution polymerization and simulated by Materials Studio. It is shown that system molecules had a certain aggregation after the long time dynamical simulation. The main driving force for the aggregation of these compounds was π bonds and hydrogen bonds. Then, the properties of polymers’energy were studied during the process of molecular dynamical simulation.The terpolymer poly(PSMA-a), composed of maleic anhydride and octadecyl acrylate was synthesized with the method of dispersion copolymerization by using polyvinylpylrrolidone (PVP) as the dispersant and ethanol as the dispersion medium. Then the polymer was amidated by aminobenzene. The final polymer (PSMA) was characterized by Fourier transform infrared spectroscopy (FTIR) and thermal weight loss (TGA).In this thesis, the crude oil from Daqing Oilfield station was taken as the experimental subject, while the magnitude of pour point depression was measured by differential scanning calorimetry (DSC), oil solidifying point tester and viscosity tester. Afterwards, the best ratio of monomer, reaction temperature, reaction time and dosage of initiator was determined through the orthogonal test. Then the results of the experiment indicated that the best effect on the magnitude of pour point depression was achieved when the amount of the PPD taken in the experiment was 750ppm and the heated temperature was 80℃.