摘要
在徐深气田的开发过程中,发现多起气井油管钢穿孔和管柱断裂事故,分析原因主要是由CO2局部腐蚀造成。为准确反映管柱穿孔失效的实际状况,开展了局部腐蚀敏感区间预测研究。通过模拟徐深气田典型井下腐蚀工况,对常用N80油管钢进行了高温高压腐蚀模拟实验,根据腐蚀形貌及局部腐蚀敏感性的分析,探索出环境因素(温度和CO2分压)对CO2局部腐蚀的影响,以及N80钢局部腐蚀的敏感温度-CO2分压组合区间,建立了CO2局部腐蚀敏感区间的预测模型。通过对比徐深气田实际失效油管与模拟实验试样腐蚀形貌,验证了N80钢CO2腐蚀类型和局部腐蚀敏感区间预测的准确性。
With the increasingly exploiting the gas field, several corrosion related failure cases,such as perforation and fracture of tubing steel did occurr in Xushen gas fields, which was thought to be the result of CO2 induced localized corrosion. In order to reveal the nature of those failure cases, the corrosion behavior of N80 steel a commonly used material for pipelines, in a high temperature and high pressure environment was studied, which arms to simulate the CO2 induced localized corrosion in the actual gas well processing practice, thereby to figure out the relation of the sensitivity to corrosion of the tubing steel with the relavant processing parameters. By characterizing the corrosion morphology and the sensitivity to localized corrosion and summing up the effect of environmental factors(temperature and CO2 partial pressure) on the CO2 induced localized corrosion of N80 steel, a corrosion map could be constructed to describe the relation of corrosion types of the N80 steel with the processing parameters temperature and CO2 partial pressure etc., thereafter, a prediction model for configuring a range of environment parameters, within which the N80 steel would be sensitive to the CO2 induced localized corrosion. Finally, it is noted that the prediction of corrosion types and the range of parameters responsible to the CO2 induced localized corrosion of N80 steel show a good agreement with the observation of the practical failure cases in Xushen gas fields.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2015年第2期188-193,共6页
Corrosion Science and Protection Technology
关键词
徐深气田
油管钢
CO2局部腐蚀
敏感区间
预测模型
Xushen gas field,tubing steel,CO2 localized corrosion,sensitive range,prediction model
