Waxy crude oil pipelines are pigged periodically to scrape the adhered wax deposit from the pipe wall and remove it from the pipeline. If wax deposition on the pipe wall is not too severe and there is not much change in pipeline throughput due to wax deposition in winter, a pigging operation in winter is inadvisable because a “paraffin blockage” may occur during pigging due to a lower operating temperature. Seasonal pigging of this pipeline is advisable if the crude oil is piped at ambient temperature in summer and the wax deposit on the pipe wall accumulated during winter is eroded by the oil flow. The pipeline should be pigged during high temperatures in summer rather than in winter. A semi-empirical wax deposition model developed by our laboratory is used to predict the wax deposit distribution along the pipeline in different seasons and the volume of pre-pigging deposit on the pipe wall, and a seasonal pigging program is recommended. An experimental method consisting of determination of the gel point of wax-contaminated oil ahead of the pig is developed to calculate the volume of wax deposits removed by the pipeline pigging operation under actual field conditions to test the model. The wax content in the crude oil is determined from the gel point. The relative discrepancy between the predicted and the field experimental pigging operation data is 12.3%.

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季节性清管管道中石蜡沉积的研究

含蜡原油管道定期清管，以刮除管壁上附着的蜡沉积物，并将其从管道中清除。如果管壁结蜡不是很严重，冬季因结蜡对管道吞吐量变化不大，则不建议冬季进行清管作业，因为清管时操作温度较低，可能会出现“石蜡堵塞” . 如果夏季原油在常温下输送，冬季堆积在管壁上的蜡沉积物被油流侵蚀，则建议季节性清管。管道应在夏季高温时清管，而不应在冬季清管。利用我实验室开发的半经验蜡沉积模型预测不同季节沿管道的蜡沉积分布和管壁预清管沉积量，并推荐季节性清管方案。开发了一种由确定清管器前蜡污染油的凝胶点组成的实验方法，以计算实际现场条件下管道清管作业清除的蜡沉积物的体积，以测试模型。原油中的蜡含量由凝胶点确定。预测和现场实验清管作业数据之间的相对差异为 12.3%。开发了一种由确定清管器前蜡污染油的凝胶点组成的实验方法，以计算实际现场条件下管道清管作业清除的蜡沉积物的体积，以测试模型。原油中的蜡含量由凝胶点确定。预测和现场实验清管作业数据之间的相对差异为 12.3%。开发了一种由确定清管器前蜡污染油的凝胶点组成的实验方法，以计算实际现场条件下管道清管作业清除的蜡沉积物的体积，以测试模型。原油中的蜡含量由凝胶点确定。预测和现场实验清管作业数据之间的相对差异为 12.3%。