A New Anelasticity Model for Wave Propagation in Partially Saturated Rocks

Elastic wave propagation in partially saturated reservoir rocks induces fluid flow in multiscale pore spaces, leading to wave anelasticity (velocity dispersion and attenuation). The propagation characteristics cannot be described by a single‐scale flow‐induced dissipation mechanism. To overcome this problem, we combine the White patchy‐saturation theory and the squirt flow model to obtain a new anelasticity theory for wave propagation. We consider a tight sandstone Qingyang area, Ordos Basin, and perform ultrasonic measurements at partial saturation and different confining pressures, where the rock properties are obtained at full‐gas saturation. The comparison between the experimental data and the theoretical results yields a fairly good agreement, indicating the efficacy of the new theory.