Preliminary model of hydrocarbon reservoir related microtremors
Published in
71st EAGE Conference & Exhibition — Amsterdam, The Netherlands
Date of publication
08 June 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 show common spectral anomalies. A preliminary model is presented which can explain the source mechanism of those microtremors. 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 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 consistent with this conceptual model.
