Materials develop anisotropic properties because of
preferred ordering of minerals or defects, i.e. fractures or cracks. This
course focuses on the causes of elastic anisotropy in rocks. Understanding
what causes anisotropy allows you to use rather than ignore anisotropy.
Anisotropy has been ubiquitously observed in seismic data. The consequences
of anisotropy for amplitude and positioning of events in x, y, z space are
treated. Anisotropy is linked to mineral, kerogen, fractures and stresses.
You will develop an understanding of what is required to characterize anisotropy
from core, logs and seismic. You will also be presented with a review of
the current understanding of the magnitudes of anisotropy in rock and its
pressure dependence. Finally, developing an appreciation for anisotropic
expressions in seismic data will allow the new knowledge to be used in
an interpretative manner.
Topics to be covered:
1) Anisotropy and its causes
2) States of stress in various tectonic and geological environments
3) Influence of stress on seismic anisotropy
4) Detection and quantification of seismic anisotropy
5) Effects of anisotropy on seismic amplitudes
6) Review of the current understanding of shale anisotropy
7) Using rather than ignoring anisotropy