Study On Synthesis And Performance Of Polyepoxysuccinic Green Scale Inhibitor

With the exploitation of crude oil,most oilfield development in China has entered the middle and late stages,the water content continues to increase,and the scaling problem seriously affects the normal production of oilfield water injection development.Among many anti-scaling and descaling measures,the addition of scale inhibitors is the most effective and economical method,so the research on scale inhibitors is particularly important.In this paper,the method of epoxidation followed by polymerization is used to synthesize the green scale inhibitor polyepoxysuccinic acid step by step.The epoxidation reaction uses maleic anhydride as the main raw material for synthesis.Under the action of catalyst sodium tungstate and oxidant hydrogen peroxide,The epoxidation reaction takes place to obtain the intermediate epoxy succinic acid,and the synthesis conditions are optimized with the yield as the research object;the polymerization reaction uses the epoxy succinic acid synthesized under the optimal reaction conditions as the raw material,Ca(OH)2 as an initiator,conduct ring-opening polymerization to obtain polyepoxysuccinic acid,and evaluate its scale inhibition performance;6 common scale inhibitors including PBTCA,HEDP,BHMTPMPA,EDTMPS,ATMP,and TH-3100 were evaluated the scale inhibition performance of the compound is optimized with PESA,and the compound scale inhibitors of BHMTPMPA,PBTCA and PESA with better effect are selected for evaluation.(1)Using single factor and orthogonal experimental methods,the effects of various factors in epoxidation and polymerization on the yield of epoxy succinic acid and the scale inhibition rate of polyepoxy succinic acid were studied.The research results show that:in the process of epoxidation,the optimal reaction condition is reaction time 1.5 h,reaction temperature 65?,sodium hydroxide to maleic anhydride molar ratio 1.5:1,catalyst dosage 0.003 mol,in this reaction condition the yield of epoxy succinic acid synthesized below can reach 92.3%.In the polymerization process,the optimal reaction conditions are reaction time 3 h,reaction temperature 90?,system pH=12,molar ratio of Ca(OH)2 to maleic anhydride is 1:12,under this reaction condition,when polymerization When the dosage of epoxy succinic acid is 6 mg/L,the scale inhibition rate reaches 90.3%.(2)The static scale method was used to investigate the relationship between the scale inhibition effect of polyepoxysuccinic acid and the amount of scale inhibitor,hardness,alkalinity,and scale formation time of the system.The results show that when the dosage of scale inhibitor is 5 mg/L,the scale inhibition rate can reach 90%;it exhibits excellent scale inhibition performance in terms of hardness and temperature resistance,but insufficient in alkali resistance.(3)Compounding PESA with 6 commonly used scale inhibitors,the results show that the compounding effect of BHMTPMPA and PBTCA is better.When PESA:PBTCA=2:3,the scale inhibition rate reaches 98.6%,when PESA:BHMTPMPA=2:1,the scale inhibition rate reached 98.1%;the evaluation of the compound scale inhibitors of BHMTPMPA and PBTCA and PESA showed that the scale inhibitors of PESA and PBTCA when the dosage of scale inhibitor was 3 mg/L The rate reaches about 95%.When the dosage of the compound scale inhibitor of PESA and BHMTPMPA is 3 mg/L,the scale inhibition rate is more than 90%.Among them,the compound scale inhibitor of PESA and PBTCA has the advantages of hardness,alkali resistance and temperature resistance.Excellent performance.