Experimental Study and Numerical Simulation of Overlying Layer Soil Failure Caused by Hydrate Decomposition
Lele Yang1, Jing Wang1, Yunhua Jiang1
1School of Marine Engineering and Technology, Sun Yat-sen University, Guangzhou 510275, China.
ACS Omega
|December 16, 2020
Summary
Hydrate decomposition from energy exploration can cause dangerous soil eruptions. This study analyzes Siberian pit data to understand how increased pore pressure from gas and water release triggers these events.
Area of Science:
- Geology and Geophysics
- Oceanography
- Environmental Science
Background:
- Hydrate decomposition, triggered by heat during energy exploration, releases gas and water, increasing pore pressure.
- This pressure buildup can lead to soil deformation, softening, and geological disasters like landslides, subsidence, and explosions.
- Natural phenomena such as Siberian pits and Bermuda craters highlight the risks associated with hydrate decomposition, potentially exacerbated by climate change impacts like ocean acidification.
Purpose of the Study:
- To investigate the mechanisms by which hydrate decomposition causes soil eruption and gas release.
- To analyze on-site data from the Siberian pit to understand pore pressure increases leading to soil eruption.
- To establish relationships between the thickness of the upper cladding layer, the pressure required for its destruction, and the resulting destruction length.
Main Methods:
- Analysis of on-site data from the Siberian pit.
- Numerical simulation to model the relationship between pore pressure, hydrate decomposition, and soil eruption.
- Investigating the influence of upper cladding layer thickness on destruction pressure and length.
Main Results:
- Established a correlation between increased pore pressure due to hydrate decomposition and subsequent soil eruption.
- Quantified the relationship between the thickness of the upper cladding layer and the pressure needed to cause destruction.
- Determined the length of destruction in the upper cladding layer as a function of pressure and layer thickness.
Conclusions:
- Hydrate decomposition is a significant driver of soil eruption and gas release, posing risks to marine environments and infrastructure.
- Understanding the mechanical properties of the upper cladding layer is crucial for predicting and mitigating eruption events.
- The study provides valuable insights for assessing geological risks associated with hydrate exploitation and climate change.
