Researchers in Skoltech have designed and conducted experiments measuring gas permeability under different conditions for ice-containing sediments mimicking permafrost. Their results can be useful both in modeling and testing techniques for gasoline generation in Arctic reservoirs and in tracing methane emission in high latitudes. The newspaper was printed in the journal Energy & Fuels.
Permafrost, though it sounds very stable and permanent, is actually quite diverse: Depending on the makeup of this frozen ground, pressure, temperature and so on, it could have varying properties, that can be incredibly important if you would like to construct something on permafrost, like an oil and gas area. Permafrost is also quite gassy: It might contain a great deal of natural gas in the form of hydrates, also its own permeability is a significant parameter both for research and for several tasks in the Arctic.
“Gas permeability affects migration and accumulation of natural gas in this frozen ground as well as atmospheric emissions. Knowledge of filtration properties of permafrost containing gas hydrates is also absolutely necessary for estimates of the possibility of extracting gas from hydrates,” says Evgeny Chuvilin, Leading Research Scientist in Skoltech and a coauthor of this paper.
Chuvilin and his coworkers chose to deal with the poorly studied issue of gas permeability variations in ice- and hydrate-soaked sand samples through freezing and thawing and as gas hydrates form and dissociate. For that, the team had to design and construct an experimental arrangement that would allow them to test various samples mimicking permafrost under different pressure and temperature conditions in addition to clay content.
“The data we got can be used in testing methods of gas extraction in permafrost areas, including from hydrates, and in mapping areas with high permeability in permafrost for methane emissions studies in the Arctic,” Chuvilin states.
Their study also showed a high probability of increasing permeability combined with dissociation of gas hydrates in permafrost–a likely scenario given the current warming trend in the Arctic. “We do not necessarily have to wait for an entire thawing of permafrost–even a slight shift of temperature is sufficient to trigger dissociation. And enhanced gas permeability that can follow will create conditions for methane emissions into the atmosphere, causing an Assortment of e