新型气田缓蚀剂的制备及其性能评价

Preparation and performance evaluation of a new corrosion inhibitor for gas field

为提高气井腐蚀防护效果,研发了一种新型缓蚀剂。选用CO_(2)饱和的NaCl-H_(2)O体系,优选缓蚀剂主剂;采用正交试验方法,筛选缓蚀剂助剂。分别采用挂片腐蚀、高温高压动态腐蚀、动电位极化实验方法测试了新型缓蚀剂性能。结果表明:研发的咪唑啉衍生物缓蚀剂主剂H-E无沉淀、无悬浮物、无分层现象,缓蚀效率以及抗点腐蚀能力优于其他四种缓蚀剂主剂。20%缓蚀剂主剂+10%阻垢剂+4%分散剂+3%协同增效剂+63%水合成的新型水溶油分散型气井缓蚀剂缓蚀性能最佳;缓蚀剂助剂影响因素主次顺序为协同增效剂>阻垢剂>分散剂。新型缓蚀剂浓度达到100 mg/L时,缓蚀率已高于95%,继续添加缓蚀剂至120 mg/L,缓蚀效率变化不大。新型缓蚀剂在液相中的抗腐蚀性能明显优于在气相中的表现。新型缓蚀剂属于以抑制阴极过程为主的混合型缓蚀剂,具有较好的气井缓蚀效果。

In order to improve the corrosion protection effect of gas well,a new corrosion inhibitor was developed.The main corrosion inhibitor was selected by using NaCl-H_(2)O system saturated with CO_(2),and the assistant corrosion inhibitor was selected by orthogonal test.The performances of the new inhibitors were tested by hanging plate corrosion test,high temperature and high pressure dynamic corrosion test and potentiodynamic polarization test.The results show that the main inhibitor of imidazoline derivative,H-E,has no precipitation,no suspended solids and no delamination,and its inhibition efficiency and anti-pitting ability are better than those of the other four main corrosion inhibitors.The corrosion inhibition performance of the new water-soluble oil-dispersed gas well corrosion inhibitor synthesized by 20%corrosion inhibitor main agent+10%scale inhibitor+4%dispersant+3%synergist+63%water is the best.The order of influencing factors of the assistant corrosion inhibitor is synergist>scale inhibitor>dispersant.When the concentration of the new inhibitor reaches 100 mg/L,the inhibition efficiency is higher than 95%.When the inhibitor is added to 120 mg/L,the inhibition efficiency changes little.The corrosion resistance of the new inhibitor in liquid phase is obviously better than that in gas phase.The new type of corrosion inhibitor belongs to the mixed corrosion inhibitor which mainly suppresses the cathodic process,and has good corrosion inhibition effect in gas wells.