Full wavefield imaging of the near surface by joint migration inversion

Abstract

Complex near-surface areas pose major problems in the imaging process for land seismic data, especially because the near-surface area can be very heterogeneous. In addition, the responses from shallow reflectors are not properly measured in order to estimate an accurate velocity model. In this paper we present an approach based on Joint Migration Inversion (JMI) for the velocity estimation and imaging. JMI automatically derives a physically consistent near-surface propagation model using the full wavefield, where the near-surface effects are encoded in the higher-order scattering effects. This approach uses all measured reflection events simultaneously and includes transmission effects and all multiples generated in both the near surface and below. Synthetic examples under realistic near-surface conditions are given to show the effectiveness of the approach.