Abstract:

There are relatively few standards and specifications related to the engineering construction, equipment manufacturing, and material selection of high sulfur natural gas purification units, and most of them adopt or refer to the standards of the petroleum refining industry. Since the Natural Gas Purification Plant of Puguang Gas Field was put into operation in 2009, high sour gas corrosion, as well as the coupling corrosion of multiple factors such as sour gas, manufacturing defects, and material defects, have caused multiple leaks of equipment and facilities, becoming the main problem that restricts the safe, efficient, and long-term operation of the plant. Through statistical analysis of abnormal events over the years, equipment inspection and maintenance records, and pressure vessel pipeline inspection records, the key corrosion areas, influencing factors, and corrosion mechanisms of high sulfur purification units are summarized. It is found that wet hydrogen sulfide corrosion, high-temperature sulfur corrosion, sulfur dioxide corrosion, and underdeposit corrosion are the main corrosion forms; the distribution patterns of corrosion are summarized from region, category, and inducement, corrosion in desulfurization and sulfur recovery systems accounts for over 80%; typical corrosion cases based on factors such as hydrogen sulfide, liquid sulfur, and manufacturing defects are analyzed in detail, and corrosion prevention and control measures are proposed for high sulfur natural gas purification units.

Key words: high sulfur natural gas, purification unit, corrosion characteristic, corrosion pattern, leakage, sour gas, high-temperature sulfur, manufacturing defects

摘要：

相关高含硫天然气净化装置的工程建设、设备制造、材料选型等标准规范较少，多采用或借鉴石油炼制行业标准。普光气田天然气净化厂自2009年投产至今，因高酸性气体腐蚀，以及酸性气体、制造缺欠、材料缺陷等多因素耦合腐蚀，引发装置设备或设施多次泄漏，成为制约工厂安全、高效、长周期运行的主要问题。通过统计分析历年异常事件、设备检维修台账、压力容器管道检测台账等，归纳了高含硫净化装置重点腐蚀区域、影响因素、腐蚀机理，得出湿硫化氢腐蚀、高温硫腐蚀、二氧化硫腐蚀、垢下腐蚀为主要腐蚀形式；从区域、类别、诱因等不同角度归纳了腐蚀分布规律，脱硫、硫磺回收系统腐蚀占比达80%以上；重点剖析了基于硫化氢、液硫、制造缺欠等因素的典型腐蚀案例，提出了高含硫天然气净化装置腐蚀防控措施，为同类酸性气田装置、设备腐蚀监检测和防控提供了借鉴。

关键词: 高含硫天然气, 净化装置, 腐蚀特征, 腐蚀规律, 泄漏, 酸性气, 高温硫, 制造缺欠