大港油田注水管线腐蚀机理研究  

Injection Pipe Corrosion Mechanisms Investigation in Dagang Oilfield

作　　者：冯庆贤[1] 要建楠 冯博舒 

机构地区：[1]中国石油天然气股份有限公司大港油田分公司,天津300280 [2]中国石油化工股份有限公司北京燕山分公司,北京102500

出　　处：《全面腐蚀控制》2014年第11期61-65,共5页Total Corrosion Control

摘　　要：大港油田的油藏温度和地层水的性质差异较大,虽然采取了很多的措施减缓注水系统管线腐蚀,但是南部地区的腐蚀速率仍较中北部高许多,因此找出问题所在很有必要。对油田所属9个注水站现场取样分析了水的性质,用静态和动态的方法分析了未灭菌和灭菌状态下腐蚀速率与盐度和硫酸盐还原菌(SRB)数量的关系。结果表明,南部地层水矿化度较高,硫酸根含量达到50-150mg/L,SRB数量不足102个/mL,但腐蚀速率较标准值高71%,中部和北部油田却相反:无菌条件下腐蚀速率高73%,注入水适合微生物生长,pH值和氧化还原电位变化规律却不同。南部油田水因矿化度高,电化学腐蚀占主导地位,此外,微生物的腐蚀也是比较明显的。电镜分析表明,腐蚀产物主要是铁、硫化物和碳酸钙。通过SRB数量和腐蚀速率实验得到了SRB对腐蚀影响,提出了控制SRB数量降低腐蚀速率的指标。The differences of temperature and formation water characteristics among each reservoir were significant in Dagang oilfield. Although many measures have been taken in an attempt to control steel pipeline corrosion, the corrosion rate in the south block of oilfield was several times higher than that of the middle and north blocks. Further studies, therefore, were needed to clarify the case. The ion and microorganism concentrations of the water in nine central stations were analyzed by sampling of aberration-free point. Under nonsterile and aseptic conditions, the relations among corrosion rate, salinity and SRB numbers were studied by static and dynamic methods. The results showed that, the salinity of formation water in the south block was the high （35g/L）, and its SO42-content ranged from 50 to 150mg/L. In the south block of oilfield, the SRB number was less than 102cell/ml, but the corrosion rate was 71 percent higher than standard value. The case in the middle and north block of oilfield was inverse：the corrosion rate was 73 percent higher than that of the aseptic condition;production water was fit for microbial growth;the change law of pH and Eh was different. In the south block of oilfield, electrochemical corrosion was the main factor due to the higher salinity. In addition, microbiologically influenced corrosion was significant. The electron microscope analysis showed that, corrosion products were mainly iron and sulfur compounds, and calcium carbonate. The influence of SRB on corrosion was obtained by experiment between SRB numbers and corrosion rates. A preliminary strategy was proposed to control and reduce SRB numbers, as well as to reduce corrosion.

关 键 词：水矿化度 动态模拟试验 静态模拟试验 指标 

分 类 号：TE988[石油与天然气工程—石油机械设备]