Velocity Estimation

Abstract

Good velocity estimates of velocity as a function of depth are of paramount importance in the interpretation of seismic data. The time-honored technique of shooting a well for velocity gives good estimates of the gross velocity layering. Fine detail is provided by continuous velocity logs. These two methods provide good, accurate information in the wells, but what can be done where there are no wells? Experience has shown that velocity functions such as a linear function with depth, V = V ₀ + az, where V₀ is the velocity at datum and a is constant, have some merit in velocity estimation (Slotnik, 1959). An intriguing idea, however, is using surface measurements to estimate the velocity from the normal moveout of seismic events.