电感耦合等离子体原子发射光谱(ICP-AES)法测定气井产出液中金属元素

Determination of Metal Elements in Gas Well Produced Fluid by ICP-AES

气井产出液中金属元素组成和含量的测定,对于集输系统缓蚀剂的配伍性研究和应用,以及判定下游天然气净化厂脱硫装置发泡、堵塞、腐蚀产生的原因均具有指导意义,因此建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定气井产出液中钾、钠、钙、镁、铁、钡元素的含量。实验确定了最佳分析谱线、样品前处理步骤和酸度等分析条件。利用膜过滤、有机溶剂萃取分离油脂和酸处理3个步骤对工业样品进行前处理,实现了6种元素同时检测。各元素在1~100μg/mL内呈良好线性关系,检出限不高于0.08μg/L,加标回收率达到97.1%~105%,重现性相对标准偏差(RSD)<3.5%;和国家标准溶液比对,方法的相对误差<4%。方法重现性和准确度均满足分析要求。方法成功地检测了气田水、酸化返排液中钾、钠、钙、镁、铁、钡组分含量,具有良好的可靠性和实用性。

The determination of the composition and content of metal elements in the produced liquid of gas wells is of guiding significance for the compatibility research and application of corrosion inhibitors in the gathering and transportation system,as well as for determining the causes of foaming,blockage and corrosion in the desulfurization unit of the downstream natural gas purification plant.Therefore,an inductively coupled plasma atomic emission spectrometry was established to determine the contents of potassium,sodium,calcium,magnesium,iron and barium in gas well produced fluid.The optimum analytical spectral line,sample pretreatment steps,and acidity were determined.The industrial samples were pretreated by three steps:membrane filtration,oil separation by organic solvent extraction,and acid treatment.The linear range of the method is 1—100μg/mL,the maximum detection limit was 0.08μg/mL,the recovery was 97.1%—105%,and relative standard deviation(RSD)was less than 3.5%;compared with the national standard solution,the relative error of the method is less than 4%.The repeatability and accuracy of the method meet the analytical requirements.The contents of potassium,sodium,calcium,magnesium,iron,and barium in gas field water and acidizing flowback fluid were successfully determined by this method.This method has good reliability and practicability.