Gas migration through soft seabed sediments
Seabed sediments contain both large and small amounts of gas. In a soft seabed sediment evidence of this gas can be seen as “pockmarks”, which most likely are scars from gas migrating upwards and through the seabed, either by the sudden emission of free gas or as a result of slow, steady gas seeps. Free gas in seabed sediments can lead to problems when drilling oil wells, and can even lead to shallow blow-outs. In some cases this may result in stability problems for the platform the well was drilled from.
To increase the understanding of the geotechnical side of the mechanisms that might play a role in the migration of gas, a preliminary study of the phenomenon was started as a co-operation with Statoil in the spring of 2005. As part of this study experiments with free gas migration in synthetic and transparent clay were carried out by a master student at the Norwegian University of Science and Technology (NTNU). A short film of these experiments can be found here.
In the fall of 2005 the project is carried on as a co-operation between Statoil, NTNU and SINTEF.
Contact person: Martine H. de Vries