非均匀介质中微侧向测井仪器的三维有限元数值分析

NUMERICAL SOLUTION OF MICROLATEROLOG DEVICES BY 3 D FINITE ELEMENT METHOD IN INHOMOGENEOUS MEDIA

在这篇文章中，分析了一个具有井眼的非均匀介质中似稳电流场的边值问题。采用了三维有限元的直接解法求解三维似稳电流场；给出了微侧向测井仪器的电极表面电流分布、假几何因子以及８英寸井眼的泥饼校正曲线；求出了在具有倾斜地层条件下，微侧向测井仪器对界面的响应。数值结果与发表的文献非常吻合，从而证明了这种方法的正确性。因此，它为新的仪器研制和微侧向测井解释提供了可靠的数据和理论依据。

This paper analyzes the quasi static current field boundary value problem in inhomogeneous media with a borehole. First, the direct solution of finite element method is adopted to solve the three dimensional quasi static current fields. Secondly, the current distribution on the electrodes of the microlaterolog devices, the pseudo geometrical factors and mudcake correction curves for a hole 8 inches in diameter are calculated. Thirdly, the responses of the microlaterolog devices are presented under the deviation of a borehole. The numerical results are very similar to the data published previously in references, and thus confirm the validity of the program. So, the reliable data is provided for the design of new sondes and the development of the computer aid logging interpretation software.