The Effecf Of Celluclast And Zosteric Acid On The Corrosion And Scaling Of Oil Field Re-injection System

Due to containing high concentrations of microorganisms, chlorine ion, hardnessand alkalinity, the re-injection water in the oil field always causes corrosion and scaling.At present, most inhibitors of corrosion and scale are non-environmentally friendly anddifficult to be degraded. So it is necessary to search for the inhibitors which are efficient,harmless to the environment and easy to biodegrade.In this paper, cellulase and zostericacid were added respectively into the oilfield re-injection water system. And the effectof adding the above agents on the corrosion and scaling process was discussed. At thesame time, corrosive and scaling the products of the oilfield re-injection water systemwere analyzed.This paper firstly analyzed the basic quality of re-injection water and predicted thecorrosion and scaling tendencies in the actual and simulated oil field re-injection water.Then cellulase and zosteric acid were added to the reactors of practical and simulatingoil field re-injection water for continuous operation. The variation ofionic concentrations in the re-injection water and the products characteristics ofcorrosion and scaling were investigated later. Finally, the mechanism of cellulase andzosteric acid to inhibit the corrosion and scale were discussed.The results showed that: cellulase had the ability to inhibit corrosion and scaling inthe short term. It could delay the appearance of crystal-form corrosion products andchange the type of corrosion products. The average inhibition rate was76.05%. Themechanisms of its inhibiting corrosion might lie in forming a single molecularadsorption layer on the metal surface. In addition, it could lead scaling product crystal form to distortion in a certain degree. However the mechanism of inhibiting scaling forthe cellulase might attribute to forming chelates with the scale-forming ions by the-COOH and-OH groups in the enzyme molecule. Zosteric acid also could slow downthe corrosion of metal pipelines in a short time. When the concentration of zosteric acidwas7140mg/L, the inhibiting rates of corrosion and scaling were respectively60%and55.88%in40days. The possible corrosion inhibition mechanism of zosteric acid wasdue to forming molecular adsorption layer on the metal surface. While the mechanismof scale inhibition may be due to the zosteric acid molecule having-COOH group,which could chelate some scale-forming ions to achieve scale inhibition.