Experimental Study On Catalyzed Upgrading And Viscosity Reduction Of Oxidized Heavy Oil

Increasing the efficiency of exploitation of heavy oil by injected air catalytic oxidation technology which is an effective gas flooding technology.The heat of oxidation was produced by the catalytic oxidation reaction generate between air and heavy oil in a low temperature.The heat of oxidation can increase oil temperature and flue gas mixed with residual air to generate the drive effect synergy.The oxygen in air can be reduced to 5%by this technology which guarantee the safety of gas drive.The shortcomings were exist in low temperature air injection production technology.Oxidized heavy oil was produced in this process which will increase the viscosity of heavy oil.The study found that for most oil,oxidized heavy oil viscosity were increased in different level which is not conducive to the crude oil gathering,so upgrading heavy nearly well ground is promising.Based on Chengbei oil as the research object,through indoor simulation of air injection exploitation process in low temperature.The property of Chengbei heavy oil which before and after the oxidation were analysised.Chengbei oxidized heavy oil was upgrading by the way of catalytic thermal upgrading and catalytic hydrothermal upgrading with using the self-made oil soluble transition metal catalyst.The viscosity,SARA and average molecular weight of Chengbei oxidized heavy oil were analysis before and after upgrading.In the thermal catalytic upgrading experiments,the viscosity of heavy oil reduce from 1813 mPa·s down to 122 mPa·s,the viscosity reduction rate is 93.27%when the catalyst amount is 0.1wt%,upgrading temperature and time are respectively 30min and 380 ? by using manganese naphthenate as catalyst.In the catalytic hydrothermal upgrading process,the viscosity of heavy oil reduce down to 591 mPa·s,the viscosity reduction is up to 67.40%when the catalyst amount is 0.1 wt%,upgrading temperature is 240?,upgrading time is 24h and the amount of water is 25wt%by using nickel naphthenate as catalyst.Oxidized heavy oil catalytic upgrading is a technique that induce the heavy oil high molecular fracture by chemical induction,such as complex macromolecules including long straight chain and aromatic ring side chain,O and S atom impurity atoms heteroatom chain and heterocyclic structure.The relationship between the changes of structural parameters and oil viscosity reducing are study through the comparative property of Chengbei oxidized heavy oil and Chengbei oxidized heavy oil modified oil,such as acid value,the elemental composition and IR spectra and 1H-NMR.The fractions between 30? to 400 ? are increase significantly after Chengbei oxidation heavy oil thermal catalytic transnature.The research show that the light fractions of modified oil increased and heavy component content decreased.The asphaltene content increased significantly indicating the existence of two reaction direction.The one is macromolecular group pyrolysis into small molecule radicals,another is transform into the new and larger molecular groups through the free radical aggregate with each other.Resin and asphaltene infrared spectra and the acid value of oil determination showed that alcohol hydroxyl,polar of the oil,phenolic hydroxyl and carboxylic hydroxyl glial significantly reduced after oxidized heavy oil catalytic hydrothermal modifiedthe.The result show that hydrogenation,desulfurization,denitrogenation and deoxidization reaction may occur in the process of the Chengbei oxidized heavy oil upgrading.The structural parameters studies have shown that,the fA of resin and asphaltene have decreased from 0.3527 and 0.4344 to 0.2658 and 0.3424,the HAU/CA of resin and asphaltene have increased from 0.9141 and 0.8458 to 1.3054 and 1.2999,the BI of resin and asphaltene have decreased from 0.3115 and 0.3559 to 0.3003 and 0.3367 after modification.The results show that the colloidal system of asphaltenes and resins and other polymer is destroyed.Reactions such as hydrogenation,fracture occurrence and ring opening make its structure transformation from aromatic carbon to naphthenic carbon and alkyl carbon,which makes the property of the oxidized heavy oil improve greatly.