posted on 2024-02-24, 16:08authored byJinnan Zhang, Huiru Sun, Yang Ge, Ziming Yang, Kehan Li
Methane
hydrate is considered as a new environmentally
friendly
energy to meet future society development. To achieve safe and efficient
hydrate production, it is critical to understand the hydrate accumulation
characteristics in different deposits, considering the geological
feature differences. In this study, the hydrate distribution characteristics
in the gas-excess and water-excess deposits were visually investigated
by using magnetic resonance imaging technology. Moreover, the effect
of the initial gas pressure on hydrate formation behaviors and stability
was analyzed. The results showed that methane hydrate first formed
in the water–gas interface for the water-excess deposit, and
then, the hydrate formation front gradually expanded into the water
phase accumulation area. Moreover, the methane hydrate distribution
was mainly determined by the initial distribution of water and gas
in the porous media. For the water-excess deposit, the spatial distribution
of methane hydrate showed an obvious heterogeneity, and the mass hydrate
accumulated at the bottom of the deposit. However, a uniform distribution
of methane hydrate in the gas-excess deposit was observed. Furthermore,
methane hydrate that formed in the higher initial gas pressure and
the water-excess environment had good stability during the water flow
process, which prolonged the duration of the hydrate decomposition
process. The findings attempt to provide valuable information and
guidelines for understanding the gas hydrate system.