Nonlinear interaction of seismic waves in the lab: A potential tool for characterizing pore structure and fluids

Malcolm, Alison and Gallot, Thomas and Burns, Dan and Brown, Stephen and Fehler, Mike (2014) Nonlinear interaction of seismic waves in the lab: A potential tool for characterizing pore structure and fluids. SEG Technical Program Expanded Abstracts 2014, 2014. pp. 2743-2748. ISSN 1949-4645

[English] PDF - Published Version Available under License Creative Commons Attribution Non-commercial. Download (757kB)

Abstract

As more and more resources are extracted from unconventional reservoirs, an understanding of the microstructure of reservoir rocks is of increasing importance. Many conventional techniques struggle to sense variations in the micro-structure and pore-fluids of rock samples. The nonlinear coupling of two elastic waves is known to be sensitive to these parameters, however, and so is a natural candidate to improve our understanding of these structures. Here, we develop an experimental technique to sense the nonlinear interaction of two propagating waves: a strong S-wave pump that changes (minutely) the elastic properties of the sample and a weaker P-wave probe that senses those changes. By measuring the delay in the P-wave probe traveltime induced by the S-wave pump, we show that this signal is significant in a Berea sandstone sample and absent in Aluminum and Plexiglass samples. The polarization of the S-wave (particle motion aligned or perpendicular to the P-wave probe) has a large impact on the measured response; this is evidence that the signal we measure is sensitive to the micro-structure of the rock. We show that the method is sensitive to fluids by imaging the variations in two specific nonlinear parameters, caused by the introduction of fluid into a Berea sandstone sample.

Actions (login required)

View Item