Physical Modelling on Gas Migration Behaviour and Its Impact on Seabed Stability
Physical Modelling on Gas Migration Behaviour and Its Impact on Seabed Stability
Significant amounts of free gas exist within marine clay sediments. An in-depth investigation into the mechanisms of gas trapping, migration, and their impact on seabed stability is crucial for enhancing the service performance of marine geotechnical engineering facilities. In this study, a physical modelling apparatus to simulate gas migration in submarine soft clay was developed, which primarily comprised a dual-cylinder plunger pump capable of long-duration, high-precision gas injection (flow rate range: 0.0001-100 mL/min, accuracy: 0.0001 mL/min) and a model box. The model seabed was prepared using Malaysian kaolin clay. Gas injection tests were conducted at a constant flow rate (10 mL/min) on two model seabeds with different strengths. Pore pressure transducers and volumetric water content sensors were employed to monitor real-time pore pressure responses and gas distribution changes within the seabed. The critical pressure for gas invasion, the rise velocity of gas bubbles, and the spatial distribution characteristics of pore pressure induced by gas migration were monitored, and the long-term existence of a stable gas cavity was observed. Moreover, the potential gas-induced evolution of seabed surface features, such as domes and pockmarks following gas eruptions, was explored. These findings facilitate our understanding of gas behaviour in marine clay and associated engineering hazard mechanisms.
Siliu Wang; Yuan Chen; Yiwen Long; Deqiong Kong; Bin Zhu
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 6: Onshore and offshore foundation systems
https://doi.org/10.53243/ICPMG2026-151