Optimization of Near-Surface Effects Correction and Velocity Modeling Using Adaptive Filtering of Structural Surfaces

摘要

The northern part of West Siberia region is notable for rapid lateral changes in seismic velocities caused by permafrost layer variations, gas deposits and overpressure zones, which ultimately distort the structural image. To increase the accuracy of depth imaging, development and implementation of new approaches, adjusted to the surface and subsurface conditions of the region, is required. This study describes the theory of optimization of velocity model construction methodology in the case of near-surface effects and the practical realization of the adaptive filtration of upper basic horizon method, which involves the use of smoothing filter with laterally variable radius. The radius is determined on the basis of best convergence with well data. The application of the method increased the accuracy of structural imaging by more than 25%.