多分量感应测井井眼及侵入影响因素分析

Numerical Simulation of Multi-component Induction Logging Tool Response with FDM

采用频率域有限差分方法实现了三维地层条件下的多分量感应测井响应模拟,该算法基于各向异性介质条件下的1组标量-矢量位方程实现Maxwell方程的求解。考察了井眼倾斜、井眼尺寸、电导性泥浆及电阻性泥浆对测井响应的影响。结果显示在大斜度井中共轴信号(z-z)比共面信号(x-x,y-y)对界面更加敏感;井眼泥浆影响最严重的是x-x分量,并且共面信号受井眼泥浆影响规律复杂多变;电导性泥浆对多分量感应测井响应影响比较明显,而电阻性泥浆在一定条件下造成的影响也不可忽视。

We achieve multi-component induction logging response simulation under the conditions of three-dimensional formation with frequency domain finite difference method （FDM）, and the algorithm is based on a set of scalar-vector potential equation under the conditions of anisotropic medium for solving Maxwell＇s equations. Also, we examine the effect on logging response from the borehole dip, borehole size, resistive and conductive mud. The simulation results show that the coaxial signal （z-z） is more sensitive to the interface than the coplanar signal （x-x, y-y） in the highly deviated wells~ it is the x-x component that is most affected by borehole mud, and the coplanar signal is affected complicatedly by borehole mud~ multi-component induction logging response is affected by conductive mud more obviously, and the impact from resistive mud can not be ignored under certain conditions.