Estimationof Gas Void Fraction in Gas-Bubble-Contained Sand with Difference Frequency Acoustic Wave

Abstract

When two primary acoustic waves of different frequencies are incident on gassy sediments, nonlinear acoustic waves can be strongly generated at the difference frequency of the primary frequencies. The nonlinearity parameter of gassy sediment is related to the gas void fraction provided the primary frequencies are lower than bubble resonance frequencies1). In this study, the nonlinearity parameter of gas-bubble-contained sand was evaluated by using a theory of the parametric acoustic array for difference frequency acoustic wave. Gas void fraction of the gas-bubble-contained sand was estimated from the evaluated nonlinearity parameter.