The effect of crack orientation on the nonlinear interaction of a P wave with an S wave

Abstract Cracks, joints, fluids, and other pore‐scale structures have long been hypothesized to be the cause of the large elastic nonlinearity observed in rocks. It is difficult to definitively say which pore‐scale features are most important, however, because of the difficulty in isolating the sour...

Full description

Saved in:
Bibliographic Details
Main Authors: J. A. TenCate, A. E. Malcolm, X. Feng, M. C. Fehler
Format: Article
Language:English
Published: Wiley 2016-06-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL069219
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Cracks, joints, fluids, and other pore‐scale structures have long been hypothesized to be the cause of the large elastic nonlinearity observed in rocks. It is difficult to definitively say which pore‐scale features are most important, however, because of the difficulty in isolating the source of the nonlinear interaction. In this work, we focus on the influence of cracks on the recorded nonlinear signal and in particular on how the orientation of microcracks changes the strength of the nonlinear interaction. We do this by studying the effect of orientation on the measurements in a rock with anisotropy correlated with the presence and alignment of microcracks. We measure the nonlinear response via the traveltime delay induced in a low‐amplitude P wave probe by a high‐amplitude S wave pump. We find evidence that crack orientation has a significant effect on the nonlinear signal.
ISSN:0094-8276
1944-8007