油田集输管道内流动流体结垢动力学研究

Fouling Kinetics Model of Flowing Fluid in Oil Gathering Pipeline

为揭示油田集输管道内的动态结垢过程,以CaCO_3为例开展了圆管内动态结垢机理研究。从流体流动过程出发,自制结垢动态分析仪,采用脉冲示踪法测试管内流体流动形态,用电导率法测定CaCO_3结垢反应速率常数,结合平均停留时间分布,建立结垢流体一维轴向分散模型。结果表明:CaCl_2、Na_2CO_3水溶液比去离子水(空白)的混返过程明显;圆管内流动过程中CaCO_3结垢的反应速率常数为0.025 L/(s·mol);根据所建立的结垢管内流体轴向分散模型得到CaCO_3垢的转化率为53.600%,与实验值的相对误差为5.438%。该模型可准确模拟圆管内流动流体结垢动力学过程,为防垢方案提供基础信息。

In order to reveal the dynamic process of scaling in oil gathering pipeline,CaCO_3 was typically introduced to explore the dynamic mechanism of scaling in circular pipes. Based on the fluid flow process,the flow patterns and reaction rate constant of CaCO_3 scaling were measured by pulse tracing method and electrical conductivity method using homemade scaling dynamic analyzer. With the average residence time distribution,the one-dimensional axial dispersion model of scaling fluid was established.The results showed that the back mixing phenomenon of CaCl_2 and Na_2CO_3water solution was more obvious than that of deionized water（blank）. The rate constant of CaCO_3 scaling during the process of flow in a circular tube was 0.025 L/（s·mol）. According to the established model,the conversion rate of CaCO_3 scale was 53.600%. The relative error between calculated value and experimental value was 5.438%,indicating an accurate prediction for the developed dynamic model,which should provide basic information for scale prevention design in circular pipe.