VELOCITY DETERMINATION OF THE NEAR-SURFACE LAYERS IN THE EARTH USING EXPLORATION 2D OR 3D SEISMIC DATA

摘要

Several methods for determining the near-surface layer velocity in the earth(can include theweathering layer velocity) from exploration seismic 2D or 3D data arepresented. These velocitymeasurements are to be used in time-correcting seismic data during dataprocessing in refractionstatics, datum statics, elevation statics derivation and application or anyother data processingscheme wherein the near-surface velocity is required. They can also be used asthe near-surfacepart of the velocity model for depth-migration of seismic data. The velocityof the near-surface isdirectly related to the character of the shot records themselves. Bystatistically measuring thischaracter from the shot records in an automated fashion, a large amount ofdata can be processedand the character measurement numerically converted to a velocity measurementusing benchmarkvelocities at the extreme high and low values of the statistical dataset.