海底管道缓蚀剂油水分配性测试方法研究及应用

Research and application of oil-water distribution testing method of corrosion inhibitor for submarine pipeline

海底管道长距离输送油气水混合流体过程中,油气水存在分离现象造成海底管道底部含水率偏高,由于二氧化碳、硫化氢等腐蚀性气体易溶于水,管道底部受腐蚀影响更为严重。不同缓蚀剂在管道油相、水相中的溶解分配情况与缓蚀剂特性及输送流体的含水率有关,发挥管道腐蚀保护作用的缓蚀剂主要是溶解在水中的缓蚀剂。高压釜动态失重腐蚀测试和电化学腐蚀测试是海底管道缓蚀剂缓蚀效果室内评价的常用方法,此两种实验方法均未考虑缓蚀剂在油相和水相中的溶解性对防腐效果的影响。为完善现有缓蚀剂评价方法,充分考虑缓蚀剂油水分配性对其效果评价的影响,使室内实验评价条件更接近管道实际运行工况,本项目开展了缓蚀剂油水分配性测试方法研究,并将此方法应用于缓蚀剂评价试验,大大提高了缓蚀剂评价工作的准确性,为海底管道安全运营提供了有力保障。

During long-distance transportation of oil-gas-water mixtures by submarine pipelines,high water content presents to the bottom of submarine pipelines due to the separation of gas-oil-water.As corrosive gases such as carbon dioxide and hydrogen sulfide are easily soluble in water,the bottom of pipelines is more seriously affected by corrosion.The dissolution and distribution of different corrosion inhibitors in oil and water phases of pipelines are related to the characteristics of corrosion inhibitors and the water cut of conveying fluids.The key part of corrosion inhibitor is that dissolved in water phase.Dynamic weightlessness corrosion test and electrochemical corrosion test by high-pressure reaction vessel are common methods for laboratory evaluation of corrosion inhibition.However this method is not considered the effects of solubility of corrosion inhibitors in oil and water phases.In order to improve the evaluation methods of corrosion inhibitors for closing to the operating conditions of pipeline,this paper carried out a research focused on the effect of corrosion inhibitors of different distribution characteristics in oil and water phase.By improving evaluation method of corrosion inhibitors,the accuracy has been increased greatly,providing powerful guarantee for submarine pipelines operation.