Synthesis And Performance Characterization Of New Crude Oil Pour Point Depressant Based On Maleic Anhydride

The oilfield mostly produces high pour point crude oil in China. High pour point of oilleads to poor low-temperature fluidity and thus difficulty in exploitation and transportation.Studies had found that benzene methyl ether and maleic anhydride could form a system ofCharge Transfer complexes (CTC) which was similar to the system of phenol-maleicanhydride.Synthesis and performance of new crude oil pour point depressant (PPD) based onbenzene methyl ether-maleic anhydride (CTC) system was mainly investigated in thispaper.Three new crude oil pour point depressant were synthesized under mild conditions, withCTC,acrylate, vinyl acetate, styrene as polymerizable monomer and BPO as a initiator. Theywere CTC-acrylate copolymer (CS), CTC-acrylate-vinyl acetate copolymer (CSE),CTC-styrene-acrylate copolymer (CSV).At the same time, a new PPD called MSFQ whichhad surface active properties was synthesized with allyl polyether by solution polymerization.In addition, in order to slove the problem of yumen oil pipeline in winter, two kinds of flowagent were developed and industrial test had been completed successfully.(1)Synthesis conditions of four kinds of PPD (CS、CSE、CSV、MSFQ) were fullyoptimized under the index of solidifying point lower value, mainly focused on the influence ofreaction temperature, reaction time, dosage of initiator and so on.(2)The performance of depressing pour point of four PPD (CS、CSE、CSV、MSFQ)combined with T-1804in different mass ratio was also evaluated respectively in thispaper.The experimental results showed when CS was combined with T-1804A at the massratio of1:1and the dose of CS was900μg·g-1,the pour point of Changqing oil could bereduced by14℃;when CSEwas combined with T-1804C at the mass ratio of3:1and the doseof CS was1800μg·g-1,the pour point of Changqing oil could be reduced by16℃;when MSFQwas combined with T1804C at the mass ratio of1:1(2:1) and the dose of CS was 3000μg·g-1,the pour point of Changqing oil could be reduced by14℃.The solidifying pointlower value of combined PPD was better than a single PPD under the same condition.(3)The relation between energy change in the process of endothermic melting andSolidifying point lower value was also explored by using Differential Scanning Calorimeter.Results showed that after adding PPD, the melting point and melting process of the crude oilwere increased in varying degree,while the melting point and melting process of PPD werereduced which was close to wax crystal phase transition temperature gradually.According tothe result of DSC, it showed the low-temperature fluidity of crude oil was good when theabsorption peaks of PPD and wax crystal were highly overlap.(4)The optimum technological conditions of PPD for Jiudong crude oil was:n(MA):n(SA)=1:1, reaction temperature85℃, reaction time6h, initiator amount0.8wt%;Theoptimum technological conditions of PPD for Qingxi and Yaerxia crude oil were:n(MA):n(SA)=1:3, reaction temperature85℃, reaction time6h, initiator amount0.8wt%.Whenpreheating temperature of crude oil is45℃,with the dose of600μg·g-1, the pour point ofChangqing oil could be reduced to6℃and the pour point of Changqing oil couldbe reducedto8℃.