射流清管技术的应用探讨与分析

为了对射流清管技术的应用进行探讨与分析，通过对清管器运动过程进行受力分析，建立射流清管器运动模型，探讨射流清管技术的关键参数，并针对射流清管技术的工程应用进行分析，提出风险应对策略。研究表明：射流清管技术的关键参数包括压降系数、旁通率、清管器与管壁的摩擦力。压降系数反映射流孔结构对压降的贡献，主要是结构参数的函数。直通结构、折流板结构和内部阀门结构的压降系数可由各组合部分线性累加计算。旁通率的优选是射流清管技术的核心，旁通率对清管器速度的影响并非理想的线性关系，增加旁通率会在一定程度上增强清管器运动的黏滑效应。当前的研究均未考虑液体润滑对摩擦力的影响且未能耦合摩擦力的沿程变化特点。本文最后对射流清管技术进行了展望，指出摩擦力沿程变化、内部阀门压降系数的研究是优化射流清管模型的重要方向，旁通率、清管器速度以及积液运移三者的耦合关系将是未来的研究热点。

Discussion and analysis of application of bypass pigging technology

For the purpose of discussing and analyzing the application of bypass pigging technology, the key parameters which have significant influence on the pig motion were analyzed by establishing the bypass pigging model through force analysis on the pig. Counter measures of eliminating the bypass pigging risks were put forward by discussing certain engineering applications. The study showed that the key parameters of bypass pigging technology included pressure loss coefficient, bypass fraction and friction between pig cups and pipe walls. The pressure loss coefficient which was the function of pig structural parameters reflected the contribution of the bypass port to the pressure drop. The pressure loss coefficient for a bypass pig with a structure of a conventional bypass port, or a deflector in the front, or an internal valve can be calculated by summing the proportion of different parts in the pig linearly. Optimizing the size of bypass fraction for a specific field condition was the core of bypass pigging technology. The variation of pig velocity in different bypass fractions turned out to be nonlinear and the pig's stick-slip behaviors intensified with the increase of bypass fraction. The effects of liquid lubrication on the reduction of the friction were always neglected by current researches which also failed to couple the variation of friction along the pigging process. Finally, the future development trend was prospected. The study on the variation of friction along the pigging process and pressure loss coefficient of a structure with an internal valve was of great significance for optimizing the bypass pigging model. Coupling the connection among bypass fraction, pig velocity and transport of liquid loading will be the future hot research topic.