Synthesis And The Scale Inhibition Of High Efficient Scale Inhibitor For Calcium,Strontium,Barium Ions With High Concentration In The Oil Field

Scale inhibition becomes more important today along with the exploitation of the oil fields and the increases of the water contents. In all scale inhibition methods, using scale inhibitor is more economic and efficient. But most scale inhibitors are only effective to one or two kinds of scales. To increase the efficiency of the scale inhibitors, people often mix the scale inhibitors to make up the deficiency of single inhibitors.This research aims at synthesizing some scale inhibitors to prevent the scale formation in the oil fields, discussing their inhibition mechanism, and mixing them to get better inhibitor formula, which is effective to most of the scales in the oilfields.A green scale inhibitor, polyepoxysuccinic acid, was synthesized, and the reaction conditions influencing the scale inhibition performance of the polymer were investigated. FTIR spectra data showed that the product has the same groups with polyepoxysuccinic acid. The scale inhibition ability of polyepoxysuccinic acid was tested in the experiment. Results showed that polyepoxysuccinic acid had excellent inhibit effect on BaSO₄ and SrSO₄ scale. The mechanism of scale inhibition was also discussed.MA-AA-VA copolymer scale inhibitor was synthesized. The best synthesized parameters of the copolymer were studied in this article. And the structure of the product was characterized by FTIR spectra. Tests showed that the MA-AA-VA copolymer had good scale inhibit properties on the CaCO₃, CaSO₄ scales. The mechanism of scale inhibition was also discussed.The structure of the MA-AA-VA copolymer was modified to resolve the problem occurring in using through adding another monomer unit to the copolymer structure. Thus MA-AA-VA-HPA and MA-AA-VA -AM copolymer were synthesized. The scale inhibit ability tests showed that the two copolymers coufd make up the deficiency of the MA-AA-VA copolymer. And the scale inhibit properties was better than the MA-AA-VA copolymer.To increase the inhibition efficiency of inhibitors, polyepoxysuccinic acid and the co-polymer were mixed. The formula of the mixture with good inhibitionefficiency was gotten in this paper. The test of the scale inhibition properties of the mixture indicates that the mixture had excellent inhibition effect on the most of the scales existed in the oil field.The mechanism of scale inhibition was discussed through the SEM of the scale. The SEM photos showed that the mixed scale inhibitor has the following scale inhibit mechanism: to the CaCO3 scale mainly is lattice distortion function, charge dispersion function, chelating solubilization and small dose effect. To the SrSC>4 scale is lattice distortion function, charge dispersion function and small dose effect. To the BaSO4 scale is small dose effect and charge dispersion function.