New insights into P -wave attenuation characteristics and mechanisms in methane hydrate-bearing sands
Year: 2025
Type: article
Abstract: SUMMARY Accurately mapping the distribution of natural methane hydrates is crucial for understanding their role in climate change and predicting the risks associated with hydrate dissociation. Attenuation shows great potential for remote hydrate detection, yet its behaviour and underlying mechanisms are still not well understood. We conducted laboratory experiments to synthesize high-saturation methane hydrate in unconsolidated sands and measure attenuation based on ultrasonic waveforms. The resulting attenuation showed an unexpected decreasing trend during hydrate formation, contradicting previous studies in sands, where attenuation generally increases with hydrate saturation. Theoretical modelling suggests that attenuation is jointly controlled by hydrate and free gas. The gas reduction in pores due to hydrate formation substantially suppresses the attenuation induced by gas-bubble oscillation, and is therefore thought to be responsible for the observed attenuation reduction. By comparison, hydrate effects are relatively weak and strongly frequency-dependent. The discrepancy between our results and previous studies arises primarily from the distinct attenuation behaviour across different ranges of gas content. Our samples fall within a relatively low gas content range, where attenuation is particularly sensitive to gas, highlighting its impact. These findings contribute new insights into the attenuation characteristics and mechanisms due to the coexistence of hydrate and gas in sediments.
DOI: 10.1093/gji/ggaf492
Authors: Tao Liu, Junguang Nie, Jiqiang Ma, Jianhua Geng
Institutions: Tongji University, State Key Laboratory of Marine Geology
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $3,416
Awards: G1679480213, G4542866158
OpenAlex ID: W4416950634