Full text loading...
-
Laboratory Modeling of the Influence of the Grain Size in Seismic Velocity and Attenutation of Unconsolidated Sediments
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
The most common method used worldwide for reservoir characterization is seismic reflection, which is sensible to variations in lithology and fluid content. However, the seismic signals are also affected by pressure, pore geometry and bedding shape. Grain size, especially in unconsolidated sediments, can also influence the propagation of these seismic signals, once it can determine the pore size distribution, porosity, wave scattering and diffraction. This paper presents a physical modeling study of the variation in seismic responses due to differences in grain size. The experiments were conducted using ultrasonic signals to perform seismic surveys on a Plexiglass block with a wedge-type cavity to simulate a reservoir. Those surveys were conducted with the reservoir filled with four different contents, one containing only the fluid phase and the other three with glass beads representing an unconsolidated medium characterized by three different grain sizes saturated with the same fluid phase. The results showed how the seismic images, velocities and attenuation can be affected by the grain size.