Theoretical and experimental studies on the physical properties and acoustic characteristics of marine gas-bearing sediments

Abstract

Marine gas-bearing sediments are extensively distributed worldwide, and the gases entrapped within these sediments hold significant potential as hydrocarbon fuels, offering a partial solution to global fuel demands. However, the presence of gas notably influences the physical properties of these sediments. Consequently, comprehensive research into gas-bearing sediments is crucial, as it will provide the critical scientific foundations to support the diversification of global energy resources and contribute to sustainable development. Building upon the theory of acoustic wave propagation in gas-bearing sediments, this study modified the acoustic model by enhancing methodologies for identifying multiple key parameters and incorporating additional physical properties of the sediment as variables. Marine gas-bearing sediment with multiple physical properties were replicated in the laboratory, and their acoustic characteristics were systematically measured. Findings indicated a direct correlation between density and compressional wave velocity, whereas logarithmic grain size, bubble void fraction, and clay content were inversely proportionate to compressional wave velocity. Notably, the trend of compressional wave attenuation contradicted that of velocity. Through comparison of experimental data with theoretical calculations, the accuracy of the modified acoustic model was verified. Sensitivity analysis was performed through numerical methods, simulating acoustic characteristics under a range of conditions to investigate the effects of sediment physical properties. To streamline the model, a double-parameter model for the acoustic characteristics of marine gas-bearing sediments was developed using multiple regression analysis theory, thereby providing novel scientific insights that can significantly advance research in the domain of energy fuels.