塔河油田注气井管道腐蚀特征及规律

 塔河油田为海相沉积形成的碳酸盐岩油田,地层液具有高矿化度、高Cl^-、高含CO₂、高含H₂S 特点,而注气井注气、焖井及生产过程中,含有溶解氧,使得腐蚀环境更加恶劣.通过分析油田碳酸盐岩油藏注气井地层采出液水、管道生产运行工况以及在注气工艺的调研基础上,应用X 射线衍射(XRD)分析、扫描电镜、能谱分析及点腐蚀影像(VMS)分析等测试分析手段,研究注气井井下及地面管道腐蚀产物及形貌特征,通过在注气井井底油管、井口及采油树内管道及地面生产管道内挂入3 种在用材质的监测挂片,研究注气、焖井及生产过程中不同监测部位的管道的腐蚀速度、形态及规律,研究规律为:从井底、井口到地面管道,随着监测周期加大,腐蚀坑的加深及加大,腐蚀速率增大;由注气过程、焖井过程向生产过程腐蚀程度逐步变大,纵向腐蚀能力增强;注气及生产过程中的35CrMo、P110S 及P110 3 种管道在用材质的耐蚀性变差.通过分析建立了注气、焖井以及生产过程中控制油田注气井井底、井口及地面管道腐蚀特征及规律的机理模型.

Tahe Oilfield Gas Pipeline Corrosion Characteristics and Rules

Carbonate oilfield in Tahe oilfield for marine sedimentary formation, formation fluid with high salinity, high Cl^-, high CO₂, high H₂S characteristics, and the injection gas well gas injection, soaking and production process, containing dissolved oxygen, make the corrosion environment even worse. Through mining based liquid water analysis, pipeline operation condition analysis and gas injection technology research for gas injection wells of carbonate rock reservoir, analysis, application of XRD diffraction intensity of scanning electron microscope, energy spectrum analysis and point corrosion image analysis VMS test analysis methods, study on the reaction of corrosion products and morphology of downhole and surface pipeline characteristics, through the pipeline in gas injection well tubing downhole, wellhead and Christmas tree and ground production pipeline hang into the three in material for monitoring coupon, to study the gas injection, soaking and production process in different monitoring sites of pipeline's corrosion rate, morphology and rule of law, to: from the bottom, wellhead to the ground pipeline, with the increase of corrosion pit monitoring period, deepen and strengthen, the corrosion rate increased; the process of gas injection, soak process to the process of corrosion degree gradually become larger, longitudinal corrosion capability is strong; gas injection and production process of 35CrMo, P110S and P110 three kinds of pipeline with corrosion resistance material change difference. And the analysis of mechanism model and a gas injection, soaking and production process control of injection well bottom, wellhead and ground pipeline corrosion characteristics and rules.