Abstract
We have collected low-noise crosswell data in a high-velocity carbonate environment with a spatial sampling interval of 2.5 ft (0.76 m). This sampling reveals a variety of coherent events not previously identified in coarsely sampled gathers. Nearly every event in our field record can be explained using simple approximations for the geology, source, and receivers without accounting for the presence of the boreholes.We have used synthetic records as a guide in a moveout-based analysis of the field data. Our analysis shows that much of the full wavefield energy, i.e., scattered waves, in our data are converted modes arising from the direct P- and S-waves. This observation suggests that for crosswell reflection imaging, the focus of acquisition and wavefield separation techniques should be on the suppression of once-converted modes.
