Numerical analysis of near-borehole and anisotropic layer effects on the response of multicomponent induction logging tools
Numerical analysis of near-borehole and anisotropic layer effects on the response of multicomponent induction logging tools
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DOI：
10.1190/1.1649382
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发表时间：
2004-01
期刊：
影响因子：
3.3
通讯作者：
M. Tompkins;D. Alumbaugh;D. Stanley;Xinyou Lu
中科院分区：
文献类型：
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作者：
M. Tompkins;D. Alumbaugh;D. Stanley;Xinyou Lu
我们提出的有限差分模拟结果，提供了新的洞察多组分感应测井工具的行为时，在各向异性层，钻孔，和侵入区的存在。我们使用四个独立的模型来研究多组分工具的性能以及典型的磁场响应。此外，关于地层倾角、层几何形状和电导率的模型变化提供了关于地质变化对多分量响应的影响的数据。模拟表明，同轴工具配置感测的深度的两倍的源-接收器偏移，虽然这个深度减少到源-接收器偏移与共面配置。横向各向同性层的存在下的数值响应提供的证据表明，各向异性可以有一个可测量的影响同轴和共面磁场，这些影响增加层倾角的增加。敏感性分析证实了这些数值结果。不同的井眼和侵入区的电导率和直径的工具响应的调查表明，共面工具的方向是更敏感的近井眼的变化比同轴配置。提出了一种频率差分技术来减轻多分量数据中不必要的钻孔引起的偏差;然而，缺点包括信号强度降低和可能的地质信号破坏。
We present finite-difference simulation results that lend new insight into the behavior of multicomponent induction logging tools when in the presence of anisotropic layers, boreholes, and invasion zones. We use four independent models to investigate multicomponent tool properties as well as typical magnetic field responses. In addition, model variations with respect to formation dip angle, layer geometry, and conductivity provide data about the effects of geological variation on the multicomponent responses. Simulations suggest a coaxial tool configuration senses a depth of twice the source–receiver offset, although this depth is reduced to the source–receiver offset with coplanar configurations. Numerical responses in the presence of transversely isotropic layers provide evidence that anisotropy can have a measurable effect on both coaxial and coplanar magnetic fields; these effects increase as layer dip increases. Sensitivity analyses substantiate these numerical results. An investigation of tool responses to varying borehole and invasion zone conductivities and diameters demonstrates that the coplanar tool orientation is much more sensitive to near-borehole variations than the coaxial configuration. A frequency-differencing technique is presented to mitigate unwanted borehole-induced bias in multicomponent data; however, drawbacks include decreased signal strength and possible geological signal destruction.