oa Multi-Mode Seismic Imaging Of Forward And Back Scattered Seismic Waves In A Cross-Borehole Physical Model

Seismic cross-borehole data are extremely complex because they usually<br>contain compressional, shear, and converted mode body waves, plus tube waves.<br>The complexity is compounded by the fact that many of the seismic events are<br>forward-reflected and forward-scattered, while conventional seismic<br>interpretation usually assumes back reflection.<br>At Colorado School of Mines, we have developed a cross-borehole<br>processing and interpretation system which: 1. Separates p-waves from swaves,<br>2, Compensates for travel time errors due to phase distortion, and then,<br>3. Converts the recorded data into images of the subsurface reflectors and<br>scatterers. Four image outputs are obtained, one each for p-p, p-s, s-p, and s-s<br>reflections/diffractions.<br>The examples shown will demonstrate that imaged cross-borehole data are<br>vastly easier to understand and interpret geologically than the original recordings.