井眼稳定性计算方法

Wellbore Stability Calculation Procedure

选用合理的钻井液密度可以减小因井眼力学原因而造成的井眼不稳定性。以纵波、横波、密度、自然伽马等测井曲线为基础资料进行计算地层力学所需参数 ,计算地层达到临界破裂的最大钻井液密度曲线和井壁达到临界坍塌的最小钻井液密度曲线 ,以得到安全钻井液密度窗口。分别介绍了这些参数的理论计算方法。给出了 2口井的应用实例 ,说明其计算方法是准确的 ,具有一定的应用价值。

Wellbore Stability Calculation Procedure.WLT, 2001, 25(4): 311～314 Litho mechanics and earth stress parameters are very important in wellbore stability calculation procedure. Proper drilling fluid density may reduce borehole unstabitity resulted from borehole mechanics. The maximum and the minimum drilling fluid density at critical formation cracking and critical borehole collapse respectively are obtained on the basis of calculating litho mechauics parameters. Values between the above two densities are the limited range of safe drilling fluid density. Calculation cases of two wells are given, which proves the procedure presented in this paper is accurate and worthy of uses.