Comparison of VSP and sonic-log data in non-vertical wells in a heterogeneous structure

Petr Bulant & Ludek Klimes

Summary

In order to compare the results of sonic-log measurements and of vertical seismic profiling (VSP), the sonic-log velocities are used to estimate the corresponding travel time in the geological structure, which is then compared with the VSP travel time.

In this paper we show how to calculate the sonic-log travel time in the geological structure from the sonic-log velocities while taking into account the effects of the non-vertical propagation of seismic waves due to the source offset and due to the heterogeneous velocity in the structure, together with the effects of well trajectory differing from strictly vertical. We also estimate the errors due to the commonly used assumption of vertical propagation.

Whole paper

The expanded abstract is available in PostScript (1 216 kB !) and GZIPped PostScript (175 kB).

Expanded Abstracts of 10th Int. Congress of SBGf (Rio de Janeiro) (CD-ROM), Brazilian Geophysical Society, 2007, SBGF0004_07 (5 pp.).
SW3D - main page of consortium Seismic Waves in Complex 3-D Structures .