海上生产水回注管材腐蚀与缓蚀剂评价研究——以南海西部油田为例  

Study on Corrosion of Pipe for Offshore Production Water Reinjection and Corrosion Inhibitor Evaluation Taking Western Oilfields in South China Sea as An Example

作　　者：秦立峰 QIN Lifeng(CNOOC Zhanjiang Branch,Zhanjiang 524057,China)

机构地区：[1]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《热加工工艺》2024年第23期115-121,129,共8页Hot Working Technology

基　　金：中海石油(中国)生产性科研项目(CCL2022ZJFN0568)。

摘　　要：针对海上油田生产水回注开发过程中管道腐蚀程度难以定量描述、腐蚀严重难以控制等问题,以南海西部油田为例,基于油田工况参数,使用高温高压反应釜开展腐蚀实验,分析了3种井筒管柱钢的腐蚀情况,并合成了一种季铵盐缓蚀剂,进行了缓蚀效果评价。然后通过电化学测试、等温吸附模型和SEM等手段确定了钢材腐蚀类型并研究了缓蚀剂作用机理。结果表明:井筒管柱钢钢在生产水回注时产生严重腐蚀,且点蚀速率较高。在加入合成的缓蚀剂后所有钢材的均匀腐蚀速率均小于0.12 mm/a,有效减缓了钢材腐蚀。生产水对钢材的腐蚀为CO_(2)/H_(2)S腐蚀,合成的季铵盐缓蚀剂为抑制阴极反应为主的混合型缓蚀剂,其在钢表面的吸附行为符合Langmuir吸附等温式,吉布斯自由能为负值,表明该吸附过程为自发过程。该缓蚀剂通过在钢材表面形成保护膜而隔绝了腐蚀介质与钢材的接触,从而有效抑制了腐蚀,可保障海上油田注水开发时管柱的安全。In view of the problems that the corrosion degree of pipeline is difficult to be quantitatively described and seriously difficult to control in the process of production water reinjection development in offshore oilfields,taking the western oilfields in the South China Sea as an example,the corrosion experiments were carried out by using high temperature and high pressure reactor based on oil field working condition parameters.The corrosion of three wellbore pipe steels was analyzed.A quaternary ammonium salt corrosion inhibitor was synthesized,and the corrosion inhibition effect was evaluated.Then the corrosion type of the steels was determined by electrochemical test,isothermal adsorption model and SEM,and the action mechanism of corrosion inhibitor was studied.The results show that the wellbore pipe steels produce serious corrosion during production water reinjection,and the pitting corrosion rate is high.After adding the synthetic corrosion inhibitor,the uniform corrosion rate of all steels is lower than 0.12 mm/a,which can effectively slow down the corrosion of steels.The corrosion of the steel by production water is CO_(2)/H_(2)S corrosion.The synthesized quaternary ammonium salt inhibitor is a mixed inhibitor mainly inhibiting cathodic reaction,its adsorption behavior on the steel surface conforms to Langmuir adsorption isotherm,and the Gibbs free energy is negative,indicating that the adsorption process is spontaneous.By forming a protective film on the steel surface,the corrosion inhibitor isolates the contact between the corrosion medium and the steels,which can effectively restrain the corrosion and ensure the safety of the pipe during the water reinjection development in the offshore oil field.

关 键 词：海上油田 生产水回注 腐蚀 缓蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]