高压气井完井管柱系统的轴向流固耦合振动研究

摘要

The interaction between conveying fluid and tubing string on mutual boundaries in high pressure gas well was considered and the influence of flow induced vibrations on the gas-filled tubing string system was analysed. The numerical fluid-structure coupled model was presented, which was then decoupled by using the method of characteristic lines. The responses of liquid pressure, pipe stress and pipe vibration velocity to the to transient excitation of unsteady gas flow were predicted, based on the data of a specific high pressure gas well. The results show that: alternating dynamic stress and reciprocating motion caused by fluid-structure interaction will aggravate completion string's fatigue damage and wear damage.%目前针对石油完井管柱的研究没有考虑瞬变流诱发的管柱运动,而实际的管柱与管内流体存在相互影响、相互作用.对完井管柱系统流固耦合振动响应进行了初步分析与探索,给出了适用于气井完井管柱流固耦合分析的数学模型,提供了采用特征线法对耦合模型进行解耦以及采用插值方法进行数值求解的具体过程,并以现场数据为例,预测分析了天然气不稳定流动引起的流体压力、管柱应力、管柱振动速度的耦合响应过程.研究结果表明:天然气不稳定流动使管柱处于交变应力状态,并诱发管柱往复运动,这将加剧完井管柱结构的疲劳破坏与磨损破坏.该结果对预防完井管柱先期实效有实际工程意义.