Laboratory and Field Experiments on Gas Transport in the Opalinus Clay of Northern Switzerland
P. Marschall and L. Holzer
Event name: 2nd EAGE International Conference on Fault and Top Seals - From Pore to Basin Scale 2009
Session: CCS and Nuclear Waste Disposal
Publication date: 21 September 2009
Info: Extended abstract, PDF ( 1.97Mb )
Price: € 20
Comprehensive laboratory and field investigations on the gas transport capacity of Opalinus Clay were conducted in the Mont Terri Underground Rock Laboratory (URL) in the Swiss Jura mountains and in a deep investigation borehole in the Molasse Basin of Northern Switzerland. Field investigations included hydraulic packer tests and gas injection tests in boreholes. The laboratory investigations on Opalinus Clay drillcores from Mont Terri comprised microstructural analyses, determination of the capillary pressure relationship and gas permeability measurements in isostatic cells. In this context advanced techniques were utilised, allowing for 3-D visualization of the microstructure of solid matter down to the nanometer scale. Fluid filled rock samples were investigated with cryo-techniques (shock freezing), which reduced substantially the appearance of artifacts associated with the sample preparation. Thus the focused ion beam-nanotomography (FIB-nt) with a resolution in the order of 10 nm and Transmission Electron Microscopy (TEM) with an expected resolution < 5nm have been applied for 3-D characterization of the pore structure of Opalinus Clay and in particular for the determination of quantitative measures of the pore connectivity.