Conceptual model of hydrocarbon reservoir related microtremors
Published in
SEG Houston 2009
Date of publication
28 October 2009
Abstract
Passive seismic low-frequency (between about 1 Hz and 6 Hz) data has been acquired at several locations around the world. Spectra calculated from this data, acquired over fields with known hydrocarbon accumulations, frequently show similar spectral anomalies. A preliminary model is presented to explain the potential source mechanism of microtremors generating the spectral anomalies. Poroelastic effects due to wave induced fluid flow and oscillations of different fluid phases are significant processes in the low-frequency range which can modify the earth’s omnipresent seismic background spectrum. These processes only occur in partially saturated rocks. We assume that hydrocarbon reservoirs are partially saturated whereas the surrounding rocks are fully saturated. Real data observations are in general agreement with this conceptual model.
