湿气管道内腐蚀直接评价方法(WG-ICDA)可对管道风险段进行等级划分,实现对管道全线的分级治理,显著降低了检测成本,提升了管道的安全性能。但由于介质环境的差异性,内腐蚀直接评价方法对某些管道的适应性相对较差,难以准确划分高风险段。采用数值模拟研究了含硫湿天然气对管道内腐蚀的影响。结果表明:天然气管道内腐蚀受积液的影响较大,管内积液为H₂S/CO₂腐蚀创造了条件,是发生局部腐蚀的重要影响因素。较多的管内积液会形成连续的积液区,积液底部腐蚀较轻微,气液界面处腐蚀较严重;若管内积液较少,由于压力和温度的变化,积液分散无序,内腐蚀反而严重。基于此,对湿气管道内腐蚀直接评价方法中的间接评价过程进行优化,并应用于塔河油田某湿气管道。评价结果表明:提出的湿气管道内腐蚀直接评价方法能更准确地判别含硫湿气管道的腐蚀风险,有效保障现场湿气管道安全运行管理。

The direct evaluation method for corrosion in wet gas pipelines (WG-ICDA) can be used to classify the risk sections of pipelines, realize the hierarchical treatment of the entire pipeline, greatly reduce the cost of inspection, and improve the safety performance of the pipeline. However, due to the difference of the medium environment, the direct evaluation method of internal corrosion has relatively poor adaptability to certain pipelines, and it is difficult to accurately divide the high-risk sections. Therefore, numerical simulation was used to study the influence of sulfur-containing wet natural gas on pipeline corrosion. The results show that the corrosion in the natural gas pipeline was greatly affected by the accumulation of liquid. The accumulation of liquid in the pipeline created conditions for H₂S/CO₂ corrosion and was an important factor in the occurrence of local corrosion. High effusion in the tube, could form a continuous effusion zone, the bottom of the effusion corroded content of slight, and the corrosion at the gas-liquid interface was more serious. The less effusion in the tube, due to changes in pressure and temperature, the effusion was scattered and disorderly, and internal corrosion was instead severe. Based on this, the indirect evaluation process in the direct evaluation method of wet gas pipeline internal corrosion was optimized and applied to a wet gas pipeline in Tahe Oilfield. The evaluation results showed that the proposed direct evaluation method for internal corrosion of wet gas pipelines could identify the corrosion risk of sulfur-containing wet gas pipelines more accurately, and effectively guarantee the safe operation and management of on-site wet gas pipelines.