A practical land data preconditioning scheme for AVO inversion based on absorption compensation in time-frequency domain

Abstract

The time-frequency domain divergence and absorption compensation (TFCOMP) is an algorithm to compensate the differences of spherical divergence and absorption among different shots in time-frequency domain. This paper presents a practical land data preconditioning scheme for AVO inversion based on TFCOMP algorithm. Firstly, the selection of pilot shot is not arbitrary but depends on if it is near enough with a well-drilling location. Thus the velocity, density and attention parameters (Q) for the pilot shot can be estimated from logging data and VSP data with enough accuracy. Secondly, visco-acoustic plane wave equation is used to compensate the spherical divergence and attenuation of the pilot shot along relevant ray paths. Thirdly, the trend of divergence and attenuation of all non-pilot shots are adjusted as the same with the trend of pilot shot in time-frequency domain. Since the compensation of pilot shot is based on accurate velocity, density and Q information, the data after TFCOMP processing will not only show a good consistency in wavelet, amplitude and frequency but also preserve its AVO characteristics correctly. The above scheme can be seen as a practical land data preconditioning scheme for AVO inversion