1. Effects of Mandrel, Borehole, and Invasion for Tilt-Coil Antennas
- Author
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Erik Jan Banning, Mark S. Haugland, Richard Martin Ostermeier, and Teruhiko Hagiwara
- Subjects
Engineering ,Mandrel ,Fuel Technology ,Tilt (optics) ,Electromagnetic coil ,business.industry ,Borehole ,Energy Engineering and Power Technology ,Geology ,Geotechnical engineering ,business - Abstract
Summary Several recently published studies discuss the concept of inductive resistivity-logging devices with oblique transmitting and/or receiving coils. Both wireline induction and logging-while-drilling (LWD) propagation resistivity-tool concepts have been considered. Directional resistivity measurements and improved anisotropy measurements are among the benefits promised by this type of device. Analyses based on point-magnetic dipole antennas were used to illustrate these potential benefits. The effects of a metallic mandrel, borehole, and invasion were not considered because of the absence of a suitable forward model. This paper characterizes mandrel, borehole, and invasion effects for a variety of candidate tilt-coil devices with antenna array parameters similar to those of the previous studies. The characterization is based on calculations from a new forward model that includes tilted transmitting and receiving coils of finite diameter embedded in a concentric cylindrical structure. Important details of the forward model used in the calculations are also provided.
- Published
- 2003