智能井井下流入控制阀结构设计及密封性能分析

Structural Design and Sealing Performance Analysis of Inflow Control Valve Used in Intelligent Well Downhole

流入控制阀是智能井技术的核心,在油气井高温高压等复杂的环境中,流入控制阀的密封效果直接影响阀的正常工作。依据智能完井工况,设计流入控制阀的结构及其金属密封结构。利用有限元分析软件ANSYS建立金属密封结构的有限元模型,分析最大过盈量、密封圈接触面的锥度、密封圈内部槽的几何尺寸、井下压力状态等敏感性参数对密封结构密封性能的影响。结果表明,随着金属密封圈最大过盈量的增加,最大接触应力降低而最大等效应力增加,而随着接触面锥度的增大接触面长度变长,接触压力和最大等效应力均呈下降趋势;内槽锥度对金属接触对影响较小,对密封圈的等效应力影响较大,内槽锥度增大,等效应力大幅增加。综合考虑应力的影响,应选择合适的最大过盈量,密封圈接触锥度不宜太大,且应尽量减小内槽面的锥度。

Inflow control valve is the core of intelligent well technology. In the complex environment of high temperature and high pressure of oilfield well,the sealing effect of the inflow control valve directly influence the normal operation of valve. According to the working condition of intelligent well,its metal seal structure and flow control valve structure were designed. The finite element model of metal seal structure was established by using the software of ANSYS,and the effect on the sealing performance of sealing structure by the sensitivity parameters was analyzed,including the maximum interference value,the taper of sealing ring contact area,the geometry size of sealing ring inner groove and the downhole pressure.The results show that with the increasing of maximum interference value of the metal seal,the maximum contact stress is reduced and maximum equivalent stress is increased. Along with the increasing of contact taper,the length of contact surface is increased,while contact pressure and maximum equivalent stress show the downward trend. The inner groove taper of sealing ring has less influence on metal contact,but great influence on equivalent stress of seal ring,and with the increasing of inner groove taper,the equivalent stress is increased greatly. Considering the influence of stress comprehensively,the suitable maximum interference value should be chosen,the contact taper of seal ring should be not too large,and the taper of the inner groove surface should be reduced as much as possible.