Azimuthal anisotropy of near surface in the Urubchen-Tokhomo Zone – an obstacle to studying cracked reservoirs

Azimuthal anisotropy of near surface as studied with P- and S-waves data is widely spread in the<br>Urubchen-Tokhomo Zone in the Eastern Siberia, and the degree of this anisotropy is very high.<br>It is characterized with rapid lateral changes not only in quantity but in symmetry direction as<br>well, being correlated to the surface topography. This causes considerable problems to analysis<br>of the deeper reservoir intervals, especially with surface techniques, and requires special investigation<br>of the near surface as well as creating new processing techniques.