重力井

其次建立了平面等曲率井中钻柱屈曲的控制微分方程和对应的泛函，在建立模型时考虑了钻柱重力、井眼曲率和上端井斜角对钻柱屈曲的影响。

Secondly , the governing differential equilibrium equations and their corresponding functional for tubing buckling in constant-curvature plane wells are derived , and the effect of gravity , well curvatures and the deviation angles at the top end of tubing is included in the analysis .

与垂直井相比，由于重力作用水平井内流体流型更加复杂，对测量和解释产生影响。

Compared with vertical wells , horizontal wells have more complex pattern due to gravity fluid flow , it will impact on the measurement and interpretation .

由于重力作用，水平井的侵入带已不再是对称于井轴的圆柱体，将侵入带等效为圆柱体，仪器（井眼）位于偏心轴上来逼近实际模型。

In order to approach the actual model , we regarded the invaded zone as a cylinder in which the tool is located in an eccentric position .