Seismic Frequency Variations of a Reservoir: Lessons from a Spring
Robert W. Wiley*, Peter Wilson, and Scott Peters
Apex Spectral Technology, USA
*[email protected]
In studying wave propagation and attenuation in the Earth, it is often convenient to use simplified models. One of these models is a mass, spring and dashpot to model oscillation and attenuation. By analyzing the motion of a spring
using
different forced oscillations, we studied the effect of the
system
’s characteristics on the transmitted frequency. In particular, we observed that if the forced oscillations are above the
system
response, the predominant output will be at the
system
characteristic. For lithologic layers, the
system
characteristics depend, in part, upon the Poisson’s ratio, matrix and the fluid velocities. With reservoirs having different fluid velocities and often different Poisson’s ratios from the surrounding rock; this implies that hydrocarbon reservoirs could have a measurable spectral character based upon their unique
system
or rock properties and that these characteristics could be estimated with seismic data.
AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain