Research On The Synthesis Of Epoxysuccinic Acids Scale Inhibitor

In the exploitation process of oil and gas field,as temperature and pressure change,inorganic salts can easily deposit in reservoir,shaft,driverpipe or oil tube.Scale will block oil pipelines and bring bad effects on normal production which can lead to production halts.PESA is a green environment-friendly corrosion and scale inhibitor without phosphorus or nitrogen.It has good scale inhibition and dispersion performance on barium,strontium and silica scale as the result of the carboxyl and ether groups in its molecular structure.Also it has excellent synergistic effect when compounded with other scale inhibitor.Epoxysuccinic acid was synthesized using maleic anhydride as raw material,hydrogen peroxide as oxidizer and tungstate as catalyst.The yield of epoxysuccinic acid was indirectly obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product.The content of maleic acid was determined by bromine addition method which was brief,fast and feasible.The relative error is less than 3.6%and the recovery is more than 94%.The concentration of tartaric acid was determined by spectrophotometric method with ferric 5-nitrosalicylate complex.This method is not affected by other interfering components in system.The relative standard deviation is less than 1.5%and the accuracy and precision is high.The results show that the optimum synthetic process are as follows:reaction temperature 70?,reaction time 1.5h,catalyst dosage 3.5%,molar ratio of sodium hydrate to maleic anhydride 2:1,mass ratio of hydrogen peroxide to maleic anhydride 1.4:1.Methanol recrystallization method can purify epoxysuccinic acid.The product is proved to be epoxysuccinic acid by TGA,IR,1H-NMR.PESA was synthesized using calcium hydroxide as initiator with anionic polymerization mechanism.By single factor and orthogonal experiments,the optimum reaction conditions were obtained as follows:reaction temperature 90?,reaction time 3h,dosage of alkali 12.24%,dosage of initiator 2.86%.Through range analysis,the order of their effectivenesses to the scale inhibition rate of PESA was as follows:dosage of alkali>dosage of initiator>reaction temperature>reaction time.Infrared spectroscopy demonstrates that the product had the same groups(methylene,carboxyl,ether)with PESA.Finally,the applicability in oil field of PESA was researched by simulating the conditions of oilfield water using scaling time,heating method,ion concentration as the object of research.