Accumulation model of natural gas hydrate in the Beaufort-Mackenzie Delta Basin, the Arctic

The Beaufort-Mackenzie Delta is an Arctic basin which contains abundant conventional hydrocarbon and natural gas hydrate. It is also one of the earliest regions in the world to carry out producing test of natural gas hydrate. To study the coexistence relationship between the hydrate and conventional hydrocarbon in the basin has not only direct significance to energy resource exploration, but also important theoretical and practical significance to seabed stability assessment, global climate change and carbon cycle research. In this paper, geological factors and stability conditions for hydrate reservoir generation was systematically summarized based on the large number of data available. Furthermore, combined with the analysis of glacier evolution, it was concluded that the accumulation of natural gas hydrate in the basin is controlled by the leakage of the underlying petroleum system and the change in permafrost zone. It is revealed that the gas source of hydrate in the basin is mainly the thermogenic hydrocarbon gas coming from the buried petroleum system. The activities of tectonic elements, such as faults and folders, were positively correlated with the enrichment of hydrate, and the hydrate occurrence was mainly related to the sand bodies of the delta plain in the Iperk, Kugmallit and Richards sequences. The permafrost above the hydrate stabilization zone plays a key role in the accumulation of gas hydrate.