In conjunction with the field test and modelling, a series of laboratory tests (gas permeability, instrument and visualisation studies, meter scale mock-up) were carried out at partner laboratories at AITEMIN and CIEMAT in Spain and VEGAS Laboratories, University of Stuttgart, Germany.

Gas permeability test at CIEMAT (SPAIN)
Link : www.ciemat.es

These tests were performed in a small cylinder and represent the scenario where the gas injection pressure is much smaller than the confining stress (see Experimental Concept section). The material in the middle of the apparatus is bentonite clay. The ports for the injection and extraction of gas can be seen at the bottom of the apparatus.

The picture on the right shows the same block of bentonite. The bentonite was doped with (lead nitrate) and the injected gas was labelled with (hydrogen sulphate). The darker areas at the bottom of the sample are a result of the chemical reaction between and whereby PbS was produced, thus the movemnt of the gas through the core can be observed.

Instrument and Visualisation studies at VEGAS Laboratories (University of Stuttgart)
Link : www.iws.uni-stuttgart.de

Tests were performed on larger cylinders (length approximately 60 cm) and represent the core injection pressure approximately equal to the confining stress.

	The horizontal cylinder tested additional instrumentation. (e.g. TDR's can be seen inside the plexiglass container).
As in the previous experiment, the gas flow pathways cna be observed by the dark areas of the core where has reacted with the to produce PbS.

Meter Scale Mock-up test at AITEMIN (SPAIN)
Link : www.aitemin.es

A mock up version of the in situ test was constructed at AITEMIN and the composite system behaviour (sand/bentonite interface with concrete silo and mortar) was tested.