AN INVESTIGATION INTO DISCREPANCIES BETWEEN SONIC LOG AND SEISMIC CHECK SPOT VELOCITIES

Abstract

Well data, and in particular Sonic Logs, are the basis for calibration of seismic data leading to improved reservoir delineation. Sonic data are adjusted to match seismic times by comparison to check shots. Recent improvements in Sonic Logging tend to show that, on average, Sonic velocities are faster than seismic velocities. The main reason appears to be frequency dependance of velocities.