| 摘要 |
<p>A fast, efficient and accurate pseudo 2-D inversion scheme (Fig. 4) for resistivity determination of an anisotropic formation (Fig. 3) uses data from a tool (3DEX) (10) comprising three transmitters (101, 103, 105) and three corresponding receivers (107, 109, 111) sampling the formation in a plurality of spatial directions. An initial model (311) of the formation including invasion zones is obtained using a conventional multifrequency and/or multispacing logging tool. A pseudo 2-D inversion scheme combines an accurate full 2-D forward solution (313) of the synthetic responses of the earth model with a 1-D approximation (323) of the sensitivity matrix (317) of the horizontally layered anisotropic background model. The timesaving compared to a regular 2-D inversion scheme can be tremendous.</p> |
