流体欠平衡钻井压力控制

摘要

In this paper,the pressure control in underbalanced drilling is studied and discussed.The theoretical basis of control method is expounded.In pressure of influence underbalanced drilling,such as drilling fluid column pressure,annulus pressure,underbalance pressure,wellhead back pressure and formation pressure etc.,the formation pressure is basic pressure.Because all pressure calculations are built on the basic pressure.On the basis of the formation pressure,rational underbalance pressure and drilling fluid density are determined.Meanwhile,application method of pressure control is presented.%对欠平衡钻井中的压力即欠压值的控制进行了研究和探讨，并对控制方法的理论依据进行了论述。认为在影响欠平衡钻井的钻井液静液柱压力、环空压耗、欠压值、井口回压、地层压力中，地层压力是首先要搞清楚的最基础的压力，最好先求出地层压力而不必急于进行欠平衡钻进，因为一切欠平衡的压力计算都是建立在这个基础压力之上的；再根据地层压力确定合理的欠压值，确定所用的钻井液密度。以最优的钻井成本，能实现最容易和最安全的钻井施工来衡量欠压值选得是否合理。举例介绍应用方法。