控压钻井气侵流动分析模型研究与应用

控压钻井(managed pressure drilling,MPD)发生气侵时,可通过实时动态压力控制在保持井底压力恒定的情况下实现气侵有效控制与安全排溢,气侵安全控制的关键是实时准确地井筒流动分析。通过理论分析建立了考虑侵入流体在不同类型钻井液中溶解析出影响的井筒气液两相流模型,考虑动态回压影响,给出了不同控压钻井模式下模型求解的初始及边界条件。基于有限差分法充分考虑不同控压模式下的压力动态调节对气体滑脱、相态变化的综合影响,给出了该模型的求解流程。运用全尺寸模拟井筒气侵测试数据对模型进行了验证分析,运用该模型对页岩气水平井控压钻井气侵控制进行了计算分析。结果表明,该模型具有较高的精度,能够很好地为控压钻井气侵控制与分析提供技术支持。

Research on Multiphase Hydrodynamic Model for MPD Kick Control and its Application

Managed pressure drilling (MPD) technique can stop and remove a kick without shut-in procedure while keeping the bottomhole pressure as constant while a kick was detected. And the key for a successful kick removal operation depend on accurate knowledge of wellbore flow analysis. A multiphase hydrodynamic model for kick control of MPD was proposed, in which the gas solubility in different drilling fluids was take into account. Furthermore, the boundary and initial conditions of this model for different MPD mode was proposed based on considering the dynamic WHP influence. Moreover, a comprehensive solution procedure was proposed, in which the influence caused by real-time adjusting of WHP for gas migration and phase change was take into account too. The proposed model has been verified with experimental data collected from scientific experimental well of SINOPEC, there is an excellent match between the calculated and measured data. Furthermore, the proposed model has been used for the shale gas horizontal MPD calculation. Therefore it can be seen that the proposed model can be applied to provide more convenient fast and precise dynamic parameters monitoring for control kick while MPD.