海底原油管道蜡沉积预测研究

Prediction Study of the Wax Deposit in Submarine Crude Oil Pipelines

国内某海底原油管道长期未进行清管作业,在没有预测管线结蜡厚度的情况下进行清管,可能会导致卡球、蜡堵事故。为了预测管道蜡层分布情况,降低清管作业的卡球、蜡堵风险,采用普适性蜡沉积模型,对各油品在不同季节、不同地段的蜡沉积速率进行了预测,并与现场清管数据进行对比验证。统计分析该管道的运行环境、操作条件和油品物性,计算油品沿程温降;结合各油品的析蜡特性,确定可能产生蜡沉积的油品种类。结果表明:此条管线海底部分管道的蜡沉积速率远高于地面部分管道,约为地面部分管道蜡沉积速率的10倍;在海底管道的出海处,蜡沉积情况最为严重;蜡沉积总量预测结果与现场数据吻合良好,二者相差17.9%,证明了预测结果的准确性,为清管作业提供了依据。

A domestic submarine pipeline has witnessed long time without pigging,and pigging without predicting the wax thickness of pipelines wax thickness may lead to plugging and wax blockage. In order to predict pipeline wax distribution and reduce the risk of plugging and wax blockage,the wax deposit rates of all kinds of oils in different seasons and positions are predicted by adopting the universal wax deposit model,and the predicted rates are compared with field pigging data. The running situation,operation conditions and oil physical properties of the pipeline are analyzed,and the oil temperature falling along the line is calculated. The oil types that may produce was deposit are determined according to the wax precipitation characteristic of oils. The results show that for this pipeline,the wax precipitation rate of its submarine part is much higher than that of ground part,about 10 times. The precipitation peaks at the mouth of the submarine pipeline. The prediction result of total wax deposition is consistent with field data,with an error of 17.9%,which proves the correctness of the prediction result and provides basis for pigging.