Submitted: Permafrost Trapped Natural Gas in Svalbard, Norway

Thomas Birchall, Malte Jochmann, Peter Betlem, Kim Senger, Andrew Hodson and Snorre Olaussen (all UNIS) have submitted and reviewed the article “Permafrost Trapped Natural Gas in Svalbard, Norway”, pending acceptance in the journal Marine and Petroleum Geology. The submitted article has been made available for members of the ARCEx consortium.

Abstract

Permafrost has become an increasingly important subject in the High Arctic archipelago of Svalbard. However, whilst the uppermost permafrost intervals have been well studied, the dynamic processes at its base have been largely overlooked. Nearly a century of coal, hydrocarbon and scientific drilling through the permafrost interval shows that accumulations of natural gas trapped at the base permafrost is alarmingly common. They exist throughout Svalbard in several stratigraphic intervals and show both thermogenic and biogenic origins. The sizes of the accumulations are highly uncertain but one case demonstrably produced several million cubic metres of gas over eight years while gas encountered on the island of Hopen is likely located in the gas hydrate stability zone. Geologically recent hydrocarbon migration must have occurred, as the formation of permafrost over the past few thousand years is the critical moment for these natural gas accumulations. In terms of sealing properties, the permafrost is relatively ice-saturated and impermeable in lowland settings whilst it is more complex and potentially dry in the highlands. There is evidence of sealing permafrost in some coastal settings, particularly in the east. In valleys, sub-permafrost aquifers show much greater flow rates than previously envisioned.

Keywords: Permafrost; Top seal; Natural Gas; Cryosphere; Greenhouse Gas; Arctic; Greenhouse Gas; Hydrates