Dispersion and Attenuation of Wave Velocity in Fluid-Saturated Rocks : Experimental Investigations
J. Fortin, J. Borgomano and S. Chapman
Event name: 81st EAGE Conference and Exhibition 2019 Workshop Programme
Session: WS01 Attenuation: Challenges in Modelling and Imaging at the Exploration Scale
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 450.31Kb )
Price: € 20
For fluid-saturated rocks, comparing ultrasonic measurements (1 MHz) in the laboratory and seismic (100 Hz) or logging (10 kHz) measurements in the field is not straightforward due to dispersion of the elastic-wave velocities. If there are several theoretical models, there is a lack of data. We developed an apparatus for measurements over a large-frequency range, by the combination of forced oscillations (0.004 to 100 kHz in apparent frequency) and ultrasonic measurements (1 MHz) at various effective pressures. Our experimental results typically show two cut-off frequencies: i) one related to a drained/undrained transition; and ii) one related to squirt flow.