青海油田高凝原油输送管线结蜡规律预测

The Forecast of the Paraffin Precipitation Law for the Pipeline Transporting High Pourpoint Crude Oil in Qinghai Oilfield

原油管道输送油品时,蜡沉积问题一直影响着管道的安全运行。基于蜡沉积机理,以青海油田花格管线为例,建立了预测实际管道中蜡沉积层厚度和蜡沉积速率的计算模型。结合环道模型沉积实验结果,采用多元线性逐步回归方法,计算得到不同工况下蜡沉积厚度及速率的变化曲线,分析了不同原油流速、冷却水温度、原油温度对管道结蜡的影响。实验结果表明:随着原油流速的增加及冷却水温度的升高,管道中同一位置处原油温度升高,蜡沉积速率降低,沉积厚度减小,管道中不易结蜡;在原油温度的变化过程中,某一个温度区间内最易形成蜡晶。

The problem of paraffin precipitation affects the running safety of the pipeline that transports oil products allthe time. Based on the principle of paraffin precipitation, and taking the lattice pipeline in Qinghai Oilfield as an example, a calculation model is established to forecast the thickness and speed of the paraffin precipitation in the realpipeline. Combining with the result of the circuit model experiment and using the method of multivariate linearstepwise regression, the changing curves of the thickness and speed of the paraffin precipitation in different working conditions are got by calculation, and the different flow rate of crude oil, temperature of cooling water and crude oil that influence pipeline paraffin precipitation are analyzed. The experiment results show that along with the increase of the flow rate of crude oil and the cooling temperature, the crude oil temperature of the same position in the pipeline goes up and the rate of the paraffin precipitation goes down, so that the thickness of precipitation decreases and the paraffin precipitation is difficult to form. Moreover, during the changing process of the crude oil temperature, paraffin crystal is most easily Formed in some temperature interval.