Reliable Interval Q-factor Estimation from VSP Data

The purpose of this paper is to present a new method for interval Q-factor estimate using near-offset VSP data. This method is based on objective function minimization of the difference between actual layered Q estimates and those calculated through interval Qs. To calculate interval Qs, we use Q estimates for all receiver pairs that provide reasonable Q values. To estimate layered Q between two receiver levels, we utilize an exponent approach which provides more accurate Q values than the spectral ratio method. Application of this method to real data demonstrates good correspondence between Q estimates and vertical velocity changes.