Influence of water thermal history and overpressure on CO₂-hydrate nucleation and morphology

Modelling of hydrate formation kinetics: State-of-the-art and future directions

“…Similar trends of an effect Table 2 Induction time for methane hydrates formed from water with different previous treatments (Vysniauskas and Bishnoi, 1983) of the thermal history of water upon the nucleation time were reported by many authors (Schroeter et al, 1983;Monfort and Nzihou, 1993;Parent and Bishnoi, 1996;Moudrakovski et al, 2001;Link et al, 2003;Lee et al, 2005a,b;Servio and Englezos, 2003;Linga et al, 2007), characterising what has been known as the memory effect in hydrate nucleation. Zatsepina et al (2004), in particular, verified that even the addition of small amounts (5-35%) of thawed water into distilled water was already enough to bring about a substantial drop in the value of t nuc . In more recent studies (Herri et al, 1999a;Watanabe et al, 2005a;Sun et al, 2007), experimental procedures have even been developed to take advantage of the memory effect for reducing the nucleation time.…”

Microstructural evolution of gas hydrates in sedimentary matrices observed with synchrotron X‐ray computed tomographic microscopy

“…Enhanced formation rates of GH from water obtained by a decomposition of crystalline hydrates (“memory water”) were repeatedly reported [ Duchateau et al ., ; Sefidroodi et al ., ; Wu and Baoyong , ; Zatsepina et al ., ], yet the issue is still controversial [ Buchanan et al ., ; Thompson et al ., ; Wilson and Haymet , ]. The enhancement of growth may well be due to the enrichment of gases in the liquid beyond the equilibrium solubility, either in a hydrophobically hydrated state or as nanometer‐sized gas aggregates embedded into the liquid; the “memory effect” therefore does not imply the presence of a relic structure of water itself facilitating GH formation.…”

Basic Research Needs for Geosciences: Facilitating 21st Century Energy Systems

“…The rates and extent of microbial immobilization of CO 2 , however, are difficult to predict since our knowledge of anaerobic microbial processes both in lab and field is based upon studies of water-saturated systems, not a mixed CO 2 /water system at high pressure (Zatsepina et al 2004). The challenge will be to parameterize this process at a scale that is useful for field-scale applications, based on comparison of laboratory microbial transformation of CO 2 under high partial CO 2 pressure in the presence of brine and various mineral/rock media for a range of microbial phenotypes with field observations.…”