| The drag reduction agent (DRA) is widely used in the field of long-distance oil pipeline for it can reduce the friction resistance in turbulent flow, improve transmission capacity, increase the flow rate and reduce the energy consumption. The DRA that we have studied at home and abroad is based on the research to improve the flow behavior of oil, it can't change the properties of the oil and the function is relatively single. The effect of the friction reduction is not ideal when only DRA is added into the heavy oil transportation pipes. Therefore we can improve the performance of the original DRA through the formulation of viscosity reducer and drag reduction agent. It can ameliorate the properties of the oil to meet the requirements of heavy oil transportation pipeline.Combining with studies of the drag reduction mechanism, prerequisites for viscosity reduction molecular design are concluded through the theoretical model and molecular simulation design approach:first, it should be oil-soluble; and then, be non-cationic surfactant. On the one hand, a special functional group is introduced into the branch of polymer drag reduction or viscosity reducer with this special functional group is added into the crude oil system. This kind of special functional group can form hydrogen bonding with the hydroxyl and carboxyl of colloid and asphaltene preferentially, and the bottom of the material with special functional group should be non-polar. On the other hand, asymmetry between nucleophilic polymer and electrophilic polymer adsorpted on the surface of colloid and asphaltene is created both in number and kind by using the diversity and asymmetry of their hydrogen bonding. Consequently, the development process of network with plane stack structure is influenced. It can prevent or weaken the formation of the structure.Viscosity reducer for heavy oil with good effectiveness is synthesized in this thesis. In the research of viscosity reduction polymer synthetisation via solution polymerization method, on-line infrared facility is used overall the process for the first time to analyse the absorbency change of various functional groups over time during the reaction process. On-line infrared spectrum analysis indicates that the absorbency of ester, phenyl, anhydride etc. is barely changed with time and functions of the original functional groups remain unchanged. While the breaking of C=C bond caused by the ternary polymerization has a specific time frame which corresponds to the control region of ternary addition copolymerization to justify the key parameter (time) of the synthetic process. HAAKE VT550 viscometer is used on viscosity reducing effect evaluation in the emulsion polymerization synthesis of octadecyl methacrylate-styrene-methacrylic acid terpolymer. According to the analysis of Daqing heavy oil, when the added amount of methyl octadecyl acrylate-based terpolymer is 300ppm and the temperature at 35℃, the viscosity reduction rate is 52.2%; and for Shengli heavy oil, when the temperature is 30℃and the viscosity reducer amount is 500ppm, the apparent viscosity turns out to be 69.8%.In the thesis, comprehensive properties of the drag reduction agent are studied via HAAKE VT550 viscometer and indoor loop evaluation system for drag reduction. Drag reduction rate calculated by theory for the ring road under the conditions of using the heavy oil as transport medium is 6.69%, which meets the requirements of the project. |
PDF Full Text Request