Crosswell reflection imaging
Guoping Li, Robert R. Stewart
A processing flow for crosswell seismic imaging with reflections is presented in this paper. It is composed of steps such as data gathering, wavefield separation, velocity analysis, moveout corrections, and stack in common reflection bin gathers. Four types of data domains, including common-shot, common-receiver, common-interval, and common-mid-depth gathers, are used for different processing purposes. Direct arrivals are removed in common-interval gathers. Reflection wavefield separation is performed in common-shot gathers. The data are corrected for vertical and horizontal moveouts in common-mid-depth gathers, with velocity information derived from a zero-interval gather. Reflection data are finally stacked in common reflection bin gathers to yield a final image. The whole processing procedure is very similar to CDP processing of surface seismic reflection data. The advantage of multi-fold coverage of crosswell seismic data is fully utilized. We will conceptually demonstrate the processing steps with a synthetic crosswell data example numerically generated from a constant-velocity medium.