快速比色管测气井产出液中铁离子浓度方法的优化

Optimization of Method for Measuring Iron Ion Mass Concentration in Produced Fluid of Gas Well by Fast Colorimetric Tube

在油气田生产过程中,钢制管线由于高温、高压、电腐蚀、药剂等因素面临着被腐蚀的情况。截至2022年底,大牛地气田通过电磁探伤、生产分析共发现腐蚀严重和套管穿孔气井51口。目前现场使用腐蚀监测的方法主要有电磁探伤及挂片法,但2种方法均面临开展周期长的问题,不能普遍运用。在管壁腐蚀过程中,铁离子含量的变化可以反映出管线被腐蚀的情况,通过对重点井的长期监测,可以分析铁离子浓度的变化,掌握气井腐蚀情况。目前使用的3种铁离子检测方法主要有邻菲啰啉分光光度法、原子吸收光谱法以及快速比色管测铁法,快速比色管法由于其检测速度迅速、方便携带的特点较适用于现场检测[1],但现场水质较复杂,使用该方法检测时往往不能准确读数,所以需要提高其检测的准确率。

During the production process of oil and gas fields,steel pipelines are faced with corrosion due to high temperature,high pressure,electric corrosion,pharmaceutical and other factors.By the end of 2022,a total of 51 gas wells with severe corrosion and casing perforation were found in Daniudi gas field through electromagnetic flaw detection and production analysis.At present,the corrosion monitoring methods used on site mainly include electromagnetic flaw detection and hanging chip method,but both of them face the problem of long development period and cannot be widely used.During the process of pipe wall corrosion,the change of iron ion content can reflect the corrosion of the pipeline.Through long-term monitoring of key wells,the change of iron ion concentration can be analyzed to grasp the corrosion situation of gas wells.The three iron ion detection methods currently used mainly include o-phenanthroline spectrophotometric method,atomic absorption spectroscopy and rapid colorimetric tube iron measuring method.The rapid colorimetric tube iron measuring method is more suitable for on-site detection due to its rapid detection speed and portability.However,the on-site water quality is complex,and the readings are often not accurate when using this method for detection,so it is necessary to improve the accuracy of its detection.