【作者】 赵淑楠；

【导师】 刘钧泉；

【作者基本信息】 华南理工大学 ， 安全技术及工程， 2010， 硕士

【摘要】 随着油田采油进入高含水期开采阶段,采油过程中会产生的大量的油田采出水。将采出水经简单处理后再回注,既可以减少环境污染,又能节约淡水资源,是提高油田的经济效益、保障油田可持续发展的一个重要途径。但是随着采出水处理系统的运行,腐蚀对该系统的危害也日益严重,许多注水管线、处理设施和回注井已多次因腐蚀而穿孔损坏,造成了严重的经济损失,甚至导致停产。针对油田产出水的腐蚀现状,本论文主要进行了以下几个方面的工作:1.对腐蚀穿孔的油田注水管线进行失效分析研究。通过对油田注水失效管线宏观腐蚀形貌、微观腐蚀形貌观察,能谱分析等方法,结合产出水水质分析结果,确定油田产出水主要腐蚀因素为溶解氧、二氧化碳、硫酸盐还原菌(SRB)、pH值、矿化度等。2.对油田产出水进行实验室静态挂片研究。静态挂片试验按挂片时间可分为两部分:短历时静态挂片正交试验和长历时主要腐蚀因素挂片试验。正交试验结果表明:主要腐蚀因素的腐蚀贡献率从大到小依次为:溶解氧>二氧化碳>pH值>矿化度等。长历时挂片试验结果表明:油田产出水的腐蚀速率随溶氧量的增大而增大,随二氧化碳含量的增大而增大,随pH值的增大而减小。3.对油田产出水的主要腐蚀因素进行电化学研究。电化学研究主要分为极化曲线和交流阻抗两个部分。电化学测试所得的主要因素对腐蚀速率影响结果和挂片试验结果基本吻合。通过对极化曲线的分析可知,A3钢在污水中的腐蚀的阳极反应主要是铁的溶解过程,阴极反应主要是吸氧腐蚀和析氢腐蚀过程。对调节油田污水含氧量的阻抗谱进行等效电路的模拟,等效电路Rs(QRt(R0L))与实际情况最为接近。4.根据油田污水挂片和电化学研究结果,对腐蚀防护措施进行了探讨,提出适宜于义和联合站的综合防腐方案主要有:水质改性技术,投加除氧剂、杀菌剂等化学药剂,应用涂层和衬里技术等。更多还原

【Abstract】 With the oil production going into the high water exploitation phase, oil production process will produce a large amount of produced water. The produced-water reinjection after simple handing not only reduce environment pollution but also save valued water resources, which is an important way in raising the economic benefit and assuring the sustainable development of oilfield. But with the coursing of the produced-water reinjection system in yihe multi-purpose station, the erosion of the system is serious increasingly. Because of corrosion, the pipes, installments and reinjection well have been damaged many times, which have given rise to much economic cost and even compelled the system to stop work. Aiming at the serious corrosion status of the oilfield produced water, the dissertation mainly includes works as below:1. The failure analysis about water injection pipeline which is corrosion perforation, by means of macroscopic corrosion morphology, micro-corrosion morphology, energy spectrum analysis etc. the author confirms that the main reason of yihe station’s produced water corrosiveness is the free carbon dioxide, the dissolved oxygen, Sulfate-reducing bacteria(SRB), pH value, the mineralization etc.2. The static hanging sheets study on oilfield produced water in the laboratory. Static handing experiments can be divided into two parts by handing time: the short duration static handing orthogonal experiments and long-lasting patch test hanging about the main corrosion factors. Orthogonal experimental results show the contribution rate order of corrosion the main corrosion factors: oxygen > carbon dioxide > pH value > mineralization degree etc. Long-lasting patch test hanging results show that the corrosion rate of oilfield produced water increases with the increase of dissolved oxygen; the corrosion rate also increases with the increase of carbon dioxide; the corrosion rate decreases with the increase of pH value.3. The electrochemical study on the main corrosion factors of oilfield produced water. Electrochemical study includes two parts: polarization curves and alternating current impedance. The results of the main factors affect to corrosion rate by electrochemical test are consistent with the hanging patch test results. Through the analysis of polarization curves we can see that the anodic reaction of A3 steel corrosion in the sewage is mainly iron dissolution process, the main cathode reactions are hydrogen corrosion and oxygen corrosion. Through the equivalent circuit simulation to the EIS of oilfield produced water, the results show that equivalent circuit Rs(QRt(R0L)) is the closest to the actual situation.4. According to the study result of oil product water, this paper raise some comprehensive anticorrosive measures fitting in with yihe multi-purpose station. Those measures mainly include water quality modification, adding oxygen scavenger and disinfectant, excluding gases in oilfield produced water, adopting catholic protection, applying metallic coating technology and so on.更多还原