Th hydrate and ices laboratory is a specialised facility that has been used for 10 years to study the behaviour of gas hydrates within sediments. The lab contains a variety of temperature controled equipment and pressure vessels capable of maintaining controlled experimental conditions representative of temperatures and pressures typical the sea bed of deep seas or below permafrost. As well as the equipment in which gas hydrates can be formed, BGS can also undertake cryogenic scanning electron microscopy (cryo-SEM) and cryogenic X-ray diffraction (cryo-XRD), both of which are capable of analysing cryo-preserved samples of hydrates or ice.
The capabilities include the following:
synthesis of carbon dioxide CO2 and methane hydrate as solid hydrates and as sediment-hosted hydrates in a variety of lithologies
simulation of permafrost through freezing wet sediments
pressure/temperature cycling, and dissociation studies of hydrates and ice
geophysical measurements on hydrates and frozen sediments
resistivity logging using non-contact methods, internal resistivity determination
determination of acoustic properties (Vp, and Vs) of hydrates and frozen sediments
Areas of investigation
Areas of investigation in which the laboratory and associated facilities have been involved include the following:
the formation of CO2 hydrate in deep-water sediments, and its relationship with pore fluids and mineral grains. This has application to sub-surface storage of CO2:
as liquid CO2 with a hydrate cap above a relatively shallow reservoir
the formation of CO2 hydrate as a secondary trapping mechanism should CO2 migrate out of a much deeper reservoir
the study of seabed core material to elucidate the relationship between natural methane hydrate and the sediment that hosts it, and the process of hydrate breakdown during warming and depressurisation
planetary science: study of hydrate and ice breakdown under low pressure/temperature conditions representative of those on Mars
Equipment capabilities have recently been enhanced by a major refit of the laboratory and now include:
a 3x3x2.4 m cold room capable of maintaining stable temperatures from -20°C to +10°C
a large (1 200 litre) cooled incubator capable of maintaining stable temperatures from -10°C to +50°C
a medium-sized (600 litre) cooled incubator capable of maintaining stable temperatures from -10°C to +50°C
a small (1 200 litre) cooled incubator capable of maintaining stable temperatures from -10°C to +50°C
Other fridges, freezers and chiller units can maintain a range of low temperatures as required.
A range of equipment can be placed into the incubators or cold room as required. This includes physical testing equipment, electronic sensors, or pressure vessels. The latter range in size from approximately 1—12 litres. Many items of equipment in the lab have been manufactured within BGS workshops, and it is possible to construct specialised equipment for specific studies.