Patent ID: 8407007
Filing Date: 2013-03-26
Classification: G01V

Abstract:
1. A method of evaluating an earth formation, the method comprising: deploying an array of seismic receivers in a borehole and recording seismic signals in the array of receivers responsive to an activation of at least one seismic source on the surface of the earth at at least one location offset from the borehole; estimating, using at least one processor, from travel times of seismic waves from the at least one location that have been reflected at an interface in the earth formation and the surface of the earth to the plurality of receivers, a velocity model including velocities of vertically propagating seismic waves in a plurality of intervals, and an anellipticity parameter related to a normal moveout velocity of compressional waves for the plurality of intervals; and using the estimated velocity model for producing an image of the earth formation above the array of seismic receivers.