Abstract
A new induction logging tool which has two coils whose axis is tilted from a borehole axis, resulting unsymmetrical configuration around a borehole is proposed. This configuration increases a sensitivity at one direction. This unsymmetrical sensor is mechanically rotated around a borehole axis and measures the electrical resistivity distribution. Comparing to other directional logging tools investigated before, the presented tool has a simple structure, but has a good directivity. Fundamental characteristics of this tool was theoretically investigated. The Born approximation, i.e., a conventional geometrical factor which has been widely used for the analysis of a induction logging system was generalized to tilt coil arrangements and was applied. The effect of tilt angle, coil separation and operation frequency were studied. A prototype model of the presented tool was fabricated and tested in a formation model. This model has inclined boundaries of formations having different conductivities. The measurement shows that this tool has a directional sensitivity as is expected from the theory. It was found from the theoretical analysis and experimental measurements that this system can measure the true resistivity of each formation as the conventional induction logging systems, and additionally it can make deep azimuthal resistivity measurement.
| Original language | English |
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| Publication status | Published - 1994 Jan 1 |
| Event | SPWLA 35th Annual Logging Symposium 1994 - Tulsa, United States Duration: 1994 Jun 19 → 1994 Jun 22 |
Other
| Other | SPWLA 35th Annual Logging Symposium 1994 |
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| Country | United States |
| City | Tulsa |
| Period | 94/6/19 → 94/6/22 |
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Energy Engineering and Power Technology