Wordmark GFZ Potsdam

Gas Hydrates in the Mackenzie Basin


Origin, Distribution and Climate Feedback Processes

Scope
In arctic regions, temperature/pressure conditions in the subsurface are favourable for the formation of gas hydrates down to more than 1000 m below the surface. The distribution however strongly depends on sedimentary facies and gas migration. Predictions of gas hydrate quantity and therefore the significance of methane from gas hydrate both as a potential climate agent and as an energy resource are so far based on scarce data. The goal of this project is to considerably reduce the error range of sub-permafrost gas hydrate quantification and to provide a database for future studies on economic importance and climate feedback processes related to gas hydrates. Modelling of the sedimentary history of the Cenozoic Mackenzie Basin will allow to identify sites of hydrocarbon generation and migration and to assess the importance of geological structures in gas hydrate formation 


  


  


The figure shows the construction of a 3D model of the Mackenzie Basin in northwestern arctic Canada, at the delta of the Mackenzie River. This is also the location of the Mallik research well, a joint research project with the geological surveys of Canada and Japan. The model was constructed from relief maps of the Tertiary units of which an example is depicted. A 1D extraction of the model shows the temperature evolution with increasing depth during the Tertiary. The model was calibrated using vitrinite reflection and temperature data measured in wells and as shown in an example, model predictions are in agreement with measured data.

3D model and temperature history of the Mackenzie Basin

Being a significant oil and gas province, the Mackenzie delta area in NW Canada is extensively covered by well log data and seismic surveys. In addition, specific information comes from the Mallik 5L-38 gas hydrate research well. There, thermogenetic gas has been found to be a main source for sub-permafrost gas hydrates. The first step therefore is to assess potential sources for gas generation and to develop transformation kinetics specific for the types of deltaic facies found in the area. Temperature history and maturation of potential Cenozoic type III source rocks are reconstructed in 2D/3D basin models. Facies specific kinetics are developed in laboratory experiments. With the sources of thermal gas identified, migration pathways can be analyzed and the focal areas of recent gas migration can be found. Thereby, the significance of gas seeping from gas fields for gas hydrate formation will be evaluated. Well log data and 2D/3D seismic surveys are then used to analyse 3D facies distribution and potential gas hydrate occurrence. These data will be used as a database for quantitative modelling of the formation and dissociation of gas hydrates in response to global warming and cooling.

Participants
 

  • K. F. Kröger
  • R. diPrimio
  • B. Horsfield
  • R. Ondrak
  • A. Saison
  • K. Bauer (Sektion 2.2)


Funding
Research activities at GFZ are sponsored as part of the IPP Project Shallow Gas in Time and Space 


  • Gashydrate im Mackenzie Becken


Last change: 02.02.2012  to top