川东北某高含硫油气田现场使用的两种尺寸BG110SS钢油管在服役1a后发生腐蚀,采用宏观观察、化学成分分析、物相分析、扫描电镜及能谱分析等方法,分析了油管腐蚀的原因。结果表明:BG110SS钢油管外壁以均匀腐蚀为主,内壁以严重的局部点蚀为主,φ88.90mm油管的腐蚀程度比φ73.02mm油管的更加严重;点蚀主要是油田高含硫环境、Cl^-富集和吸氧腐蚀的共同作用下导致的,S^2-、HS^-和CO₂渗透至基体表面,加剧了基体腐蚀,在环境、载荷等多因素耦合作用下,导致油管腐蚀逐渐发展。

Corrosion occurred on BG110SS steel tubing with two sizes after one year of service in a high sulfur oil and gas field in northeastern Sichuan. The causes of corrosion of tubing were analyzed by means of macroscopic observation, chemical composition analysis, phase analysis, scanning electron microscopy and energy spectrum analysis. The results showed that homogeneous corrosion was dominant on the outer wall of BG110SS steel tubing, and severe local pitting corrosion was dominant on the inner wall. The corrosion degree of the tubing with size of φ88.90 mm was more serious than that of the tubing with size of φ73.02 mm. Pitting corrosion was mainly caused by S^2-, HS^- and CO₂ permeating to substrate surface under the combined action of high sulfur environment, Cl^- enrichment and oxygen absorption corrosion, which aggravated the substrate corrosion. Under the coupling action of environment, load and other factors, corrosion gradually expanded on the tubing.