Study On Upgrading And Viscosity-reducing Effects Of Ionic Liquids On Heavy Oil

In recent years,with the continuous exploitation of crude oil,the remaining unexplored oil will be worse,which makes the oil industry is facing enormous challenges.Because of the characteristic of heavy oil reservoirs,it is difficult to recover heavy oil with conventional mining technology,so some special technical measures should be taken to modify its viscosity reduction treatment,in order to reduce the difficulty of mining.Ionic liquid as a green solvent attracted wide concern in applied research in the heavy oil upgrading.Four kinds ionic liquids were synthesized in this study,which are1-butyl-3-methylimidazoliumchloride?[Bmim]Cl?,1-butyl-3-methylimidazoliumtetrachloroferrate?[Bmim]Cl·xFeCl₃?,Triethylamine hydrochloride nickel chloride?Et₃NHCl·x NiCl₂?and1-butyl-3-methylimidazolium perchlorate?[Bmim]ClO₄?,Their chemical structures were characterized by FTIR and ¹HNMR.The effects of the amount of the ionic liquids added,reaction time and reaction temperature on the viscosity reduction of heavy oil were studied.The SARA of heavy oil were studied.The content of the heavy oil light component is increased and the heavy component is reduced after the treatment with ionic liquid,so that the flowability is increased.The above four kinds of ionic liquids have good viscosity reduction effect,but the best ionic liquid is[Bmim]Cl·xFeCl₃.The optimum reaction conditions with heavy oil are as follows:mole fraction of FeCl₃is 0.35,concentration of ionic liquid is 0.25%,reaction temperature is80?,reaction time is 12h,viscosity reduction rate is 44.1%.At the same time,the saturated and aromatic increased from 31.65%and 17.3%to40.37%and 28.67%.The resin and asphaltene decreased from 38.82%and 11.03%to 24.46%and 5.36%.Additionally,a lot of other ionic liquids were studied,the effect are not as good as above four kinds ionic liquids.Through the study of a variety of ionic liquids,summarized as follows,under the same conditions,the ionic liquid with longer carbon chain has better effect on the viscosity reduction.It may be appropriate to add hydrogen donor toluene during the heavy oil upgrading with ionic liquid,the addition of the hydrogen donor can be used as a stabilizing agent.