为了掌握无法进行内检测的海底管道的内腐蚀情况,以南海某湿气管道为例,通过多相流软件模拟海底管道的实际流动状态,采用NORSOK模型计算海底管道的腐蚀速率,采用湿气管道内腐蚀直接评价方法(WG-ICDA)预测了管道腐蚀的高风险位置,并引入灰色关联分析法判断海底管道内腐蚀的主要影响因素。结果表明:该海底管道为轻度腐蚀,立管段、低洼区域管段及管道前110 km范围内的管段为腐蚀高风险位置;确定再评价时间间隔为8 a;多相流模拟与腐蚀挂片试验的结果基本一致,证明了WG-ICDA具有一定的可靠性;压力、CO₂分压、温度和液膜速率是海底管道内腐蚀的主要影响因素。

In order to grasp the internal corrosion of submarine pipelines that cannot be tested internally, taking a wet gas pipeline in the South China Sea as an example, the actual flow state of the submarine pipeline was simulated by multiphase flow software, and the NORSOK model was used to calculate the corrosion rate of the submarine pipeline. Wet gas internal corrosion direct assessment methology (WG-ICDA) for pipelines was used to predict the high risk position of pipeline corrosion, and grey correlation analysis method was introduced to judge the main influencing factors of submarine pipeline internal corrosion. The results showled that the submarine pipeline was mildly corroded. The stand pipe section, low-lying pipe section and pipe section within the first 110 km of the pipeline were high-risk locations for corrosion. The re-evaluation time interval was determined to be 8 a. The results of multiphase flow simulation and corrosion coupon test were basically consistent. It was proved that WG-ICDA had certain reliability. Pressure, CO₂ partial pressure, temperature and liquid film velocity were the main factors affecting the internal corrosion of submarine pipelines.