中原油田三相分离器垢下腐蚀行为及防护措施研究

发布时间：2018-06-01 05:00

本文选题：三相分离器 + 20#钢　；参考：《重庆科技学院》2015年硕士论文

【摘要】：随着中原油田进入特高含水开采期，导致三相分离器出现了不同程度的垢下腐蚀现象，分离器本体腐蚀穿孔频发，大大降低了分离器的使用寿命，甚至引发重大安全生产事故。目前，中原油田三相分离器垢下腐蚀原因尚不明确，相关研究尚不系统全面。因此开展分离器垢下腐蚀行为及防护措施研究具有重要的学术价值和工程应用意义，，为监测并控制分离器垢下腐蚀提供参考理论依据。本文通过现场调查分离器结垢部位和垢样XRD、SEM分析、实验室垢下腐蚀影响因素和腐蚀特性试验、缓蚀阻垢剂优选评价试验和牺牲阳极材料优选评价试验，得到了中原油田三相分离器垢下腐蚀机理及防护措施实施方案。主要研究内容和结论如下： (1)通过现场调查油田正在使用的51台分离器后发现：在分离器内部构件直管段、变径处、转弯处以及分离器筒体的中下部容易集结成垢，发生垢下腐蚀。XRD分析显示垢样主要成分为CaCO3、SiO2和少量CaSO4、BaSO4、SrSO4，垢下腐蚀产物主要成分为：Fe2O3、FeCO3、FeS等。 (2)确定CO2电化学腐蚀、Cl－导致的点蚀和SRB细菌腐蚀是造成分离器垢下腐蚀的主要原因。利用高温高压反应釜模拟分离器工矿环境，研究了温度、CO2分压、Cl－含量、流速、SRB五个因素对垢下腐蚀速率的影响特性。正交试验结果显示，五个因素对分离器本体垢下腐蚀速率影响程度的大小依次为：SRB含量＞CO2分压＞Cl－浓度＞工作介质温度＞工作介质流速。 (3)通过常压静态初选试验、高温高压动态评价试验、模拟分离器工况环境动态评价试验，从12种缓蚀阻垢剂中优选出了ZY-7、ZY-10两种缓蚀阻垢剂，投加浓度为200mg/L时缓蚀阻垢率均超过80%，可以应用于中原油田分离器垢下腐蚀防护现场；通过牺牲阳极材料优选评价试验，优选出Al-Zn-In三元铝合金作为分离器牺牲阳极保护材料，现场应用试验表明，其平均保护度达到94.76%，现场试验结果达到防腐要求。在此基础上，提出了中原油田分离器垢下腐蚀防护措施实施方案。
[Abstract]:With Zhongyuan oilfield entering into the period of super high water cut, the three-phase separator appears different degree of scale corrosion phenomenon, the separator body corrosion perforation frequently occurs, greatly reduces the separator service life, even causes the important safety production accident. At present, the reason of corrosion under scale of three-phase separator in Zhongyuan Oilfield is not clear, and the related research is not systematic. Therefore, it is of great academic value and engineering application significance to study the corrosion behavior and protective measures under scale of separator, and to provide a theoretical basis for monitoring and controlling the corrosion under scale of separator. In this paper, the factors affecting corrosion under scale in laboratory and corrosion characteristic test, the optimum selection and evaluation test of corrosion inhibitor and sacrificial anode material are studied by field investigation of scale forming site of separator and scale sample by XRDX SEM. The corrosion mechanism under scale of three-phase separator in Zhongyuan Oilfield and its protective measures are obtained. The main contents and conclusions are as follows: 1) through the field investigation of 51 separators in use in the oil field, it is found that scale is easily accumulated in the straight pipe section of the internal component of the separator, at the variable diameter, at the corner, and in the middle and lower parts of the separator cylinder. The results of scale corrosion. XRD analysis showed that the main components of scale samples were CaCO3SiO2 and a small amount of CaSO4, BaSO4, SrSO4, and the main components of corrosion products under scale were:% Fe2O3FeCO3Fe3FeS and so on. (2) the pitting corrosion caused by CO2 electrochemical corrosion and the corrosion of SRB bacteria are the main causes of the corrosion under the scale of the separator. By using high temperature and high pressure reactor to simulate the industrial and mineral environment of separator, the effects of temperature and CO _ 2 partial pressure (CO _ 2) content and SRB on the corrosion rate under scale were studied. The results of orthogonal test show that the influence of five factors on the corrosion rate of the separator is in the order of: SRB content > CO2 partial pressure > Cl-concentration > working medium temperature > working medium flow rate. Through static primary test of atmospheric pressure, dynamic evaluation test of high temperature and high pressure, dynamic evaluation test of simulated separator working condition, two kinds of corrosion and scale inhibitor ZY-7 and ZY-10 were selected from 12 kinds of corrosion and scale inhibitor. When the concentration of 200mg/L is added, the corrosion and scale inhibition rate is more than 80%, which can be used in the field of corrosion protection under scale of separator in Zhongyuan Oilfield, and the Al-Zn-In ternary aluminum alloy is selected as the sacrificial anode protection material through the optimal selection and evaluation test of sacrificial anode material. The field application test shows that the average protection degree is 94.76 and the field test results meet the requirements of anticorrosion. On this basis, the implementation scheme of corrosion prevention measures under scale of separator in Zhongyuan Oilfield is put forward.
【学位授予单位】：重庆科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE983

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