Exploring stress-dependent acoustic velocity hysteresis in rocks

A preliminary study

Absztrakt

Knowledge of acoustic wave velocity in rocks is essential for geophysical studies, as it helps identify geological structures that may contain hydrocarbon accumulations. Acoustic velocity is strongly influenced by pressure and the presence of pore volume. This paper integrates experimental data with theoretical modeling to investigate stress-dependent acoustic velocity hysteresis in rocks and to analyze how stress affects acoustic velocity during loading and unloading. The study focuses on quasi-static elastic properties and introduces a new petrophysical model that explains acoustic hysteresis through pore closure and opening, thereby affecting P-wave propagation. The model is consistent with the observed data and provides a coherent framework for understanding the interactions among stress, pressure, and acoustic behavior. To validate the model, a sandstone sample was tested under incremental pressures, and the model parameters were determined using a linearized inversion method. The calculated and measured velocities showed close agreement, confirming the model’s applicability.