Patent ID: 6868037

Claim:
A method for measuring velocity pertaining to the weathered and/or subweathered layers in the earth using travel times of a plurality of different waves, generated by a drill bit while drilling a borehole using a drill string, said method comprising the steps of: recording vibration data by locating seismic energy from the drill bit as the drill bit penetrates through rock layers in the near surface of the earth near the borehole using three-component seismic sensors deployed on the ground surface and the drill string; cross-correlating the vibration data recorded on sensors mounted on the drill string and the ground surface; identifying, in the cross-correlated vibration data, reflected, refracted and converted waves so as to measure a travel time of each identified wave; performing a joint tomographic inversion of the travel times of the vibration data using each measured travel time to develop a near surface replacement model; and applying the near surface replacement model to correct surface seismic data in three dimensions.