Institute of Petroleum Engineering

Centre for Gas Hydrate Research Publications

Abstract 059
Gas Hydrates in Porous Media: A Visual Investigation Using Glass Micromodels
Anderson, R., Biderkab, A.-B., Tohidi, B., Burgass, R. W., and Østergaard, K. K.
EAGE 9th Annual Research Review, Edinburgh, UK, 14 February (2001).
Natural gas hydrates (or clathrates) are widespread in their occurrence, with suitable conditions for their formation existing both along the continental slopes, and in the subsurface of arctic permafrost regions. In addition to being a hazard to deep-water hydrocarbon drilling operations, the huge volumes of methane trapped as gas hydrates have the potential to be an important strategic energy reserve, but also have the potential to be a major contributor to global warming. The stability of hydrates in natural sediments is controlled not only by P/T conditions, but by the complex interaction of many factors, including pore-size distribution, pore fluid properties and sediment grain mineralogy. With the long-term aim of recreating as realistically as possible the sedimentary environment, we report preliminary results on the visual observation of gas hydrate formation, redistribution, and dissociation at the microscopic scale in glass micromodels, representing porous sedimentary media. In this presentation, video clips on hydrate formation, re-distribution and dissociation from both a free gas phase (CH4-water), and from gas saturated water only (CO2-water) will be presented. The results provide the first unequivocal visual evidence that gas hydrates can form in systems without the presence of a free gas phase. The study provides a unique insight into hydrate formation and dissociation, phase saturation and distribution within porous media, cementing properties of hydrates, and their relations to grain size and volume of hydrates present in the system.