元坝高含硫气田地面系统腐蚀主控因素研究

元坝气田天然气中高含H2S、CO2,随着气田出水量增大、矿化度升高,地面系统腐蚀环境越来越复杂。为找出影响元坝气田地面系统腐蚀的主控因素,建立了以CO2分压、H2S分压、液气比、pH值、矿化度、Cl-含量、缓蚀剂残余浓度为自变量,腐蚀速率为因变量的灰关联分析方法。通过数据挖掘,分析了各种因素对腐蚀的影响程度。结果表明,当前元坝气田地面系统腐蚀的主控因素为H2S分压、液气比和CO2分压,故可适当优化缓蚀剂添加方案,调整批作业清管周期,合理降低缓蚀剂清管作业成本。研究成果为元坝气田地面系统的完整性管理提供了技术依据。

Study on main control factors of surface system corrosion in Yuanba high sulfur gas field

The natural gas in Yuanba gas field contains high H2S and CO2.With the increase of water output and the increase of mineralization,the corrosion environment of surface system becomes more and more complex.In order to find out the main control factors that can affect the ground system corrosion of Yuanba gas field,this article establishes a grey correlation analysis method which takes CO2 partial pressure,H2S partial pressure,liquid-gas ratio,pH value,salinity,Cl-concentration,and corrosion inhibitor residual concentration as independent variables,and corrosion rate as dependent variable.The influence degree of various factors on corrosion is analyzed by data.The results show that the main control factors of the ground system corrosion in Yuanba gas field are CO2 partial pressure,H2S partial pressure and liquid-gas ratio.Therefore,it is possible to appropriately optimize the corrosion inhibitor addition program,adjust the batch operation cycle,and reasonably reduce the cost of corrosion inhibitor pigging operation.The research results provide a technical basis for the integrity management of the ground system in Yuanba gas field.