FORMATION, OCCURRENCE AND DISSOCIATION OF MARINE SEDIMENTARY GAS HYDRATES, RESEARCH OF EPHEMERAL BENTHIC PROCESSES WITH IN-SITU TECHNOLOGY

Hans Amann¹, Eric Anders¹, Michael Maggiulli¹, Thjunjoto¹, Gert J. De Lange², Anke Daehlmann², John Parkes³, Derek Martin^3
1 FG Maritime Technik, Technische Universitat, Berlin, Germany
² Geosciences, Utrecht University, The Netherlands,
³ Earth Sciences, University of Cardiff, Wales, United Kingdom

Growing evidence shows that high pressure processes of bio- and geochemical, fluid- and thermodynamic interactions of the extreme deep sea sedimentary environment of gas hydrates and the associated micro biology, need to be researched as in-situ phenomena. Ex-situ research can give only limited answers. A new technological solution for this task is being actually provided by methods and tools of in-situ sampling and monitoring. Benthic conditions of sediment structure, temperature, pressure and bio-geochemistry are maintained, brought to the lab and evaluated under quasi in-situ conditions. Process parameters of the deep sea ecology, such as salinity, oxygen content or pH are being monitored during sampling.

MAT and partners are developing suites of methods and tools for such pristine in-situ coring, monitoring and sub sampling for bio-geosciences, reservoir engineering and ecology. Examples to demonstrate the scientific potential of autoclave technology are being detailed. Selective and targeted pore water and gas analyses on pressurised cores are used to establish spatial profiles and to understand the distribution of gas hydrates, gas and water in-situ. Defined and contamination controlled sub-samples, which “have never seen the atmosphere”, are prerequisites for any in-situ analysis of microbiological and geo-chemical processes. Pressure and temperature related process phenomena such as carbonate precipitation from depressurised pore water or AMO (Anaerobic Methane Oxidation), can then be investigated in controlled lab conditions. So far unknown but characteristic microstructure and reservoir engineering implications of in-situ marine gas hydrates will become known. In-situ technology enables science to determine the true geo-scientific and micro-biological scope, of ephemeral benthic processes, the environmental implications and the energy potential of marine gas hydrates. Research and development are being performed in national and international scientific partnerships, mainly projects sponsored by the EU Commission.