【摘要】 以钻井环空多相非稳态流理论为基础,根据气-液两相流体在井筒流动过程中遵循的基本方程,利用有限差分的数值解法进行求解,刻划了井内流体的各种运动特性以及瞬态压力平衡关系,提出了利用井口回压对井内各流动参数进行控制,找出了井口回压和气体侵入量对井内各种流动参数的影响关系和规律,得出一些指导欠平衡钻井的有益的结论,对进一步深化和完善欠平衡钻井和井控理论研究以及现场应用具有重要的现实意义。更多还原

【Abstract】 Based on the theory of unstable multiphase flow in annulus and gas & liquid flowing equation, the paper describes the flowing characteristics of fluids and relationship of instantaneous pressure balance in the well bore by using finite differentiation numeric methods. Further more, the paper finds the influence of the well head back pressure & gasinflux on the various flowing parameters of hole and draws some useful conclusions that can not only be used to direct the study on UBD and well control but also provide an important reference for field applications.更多还原