TY - GEN
T1 - Chemical influence of pore pressure on brine flow in clay-rich material
AU - Cassini, Etienne
AU - Mylnikov, Danila
AU - Makhnenko, Roman
N1 - Publisher Copyright:
© Springer International Publishing AG 2017.
PY - 2017
Y1 - 2017
N2 - Hydromechanical properties of shales are complex due to the involved material structure, with the solid matrix being mainly formed by swelling clays and porosity dominated by nanometer scale tortuous voids with large aspect ratios. Intrinsic permeability of restructured Opalinus Clay (Swiss shale) brought to shallow geological storage conditions was measured with in situ brine. Under constant temperature, vertical stress, and downstream fluid pressure, steady-state flow experiments show a significant trend of permeability decrease with increasing differential (upstream minus downstream) fluid pressure, thus contradicting the conventional Darcy’s description. To interpret these experimental measurements, brine permeability is derived using a one-step self-consistent homogenization scheme based on the knowledge of material’s pore structure. While mechanical and thermal effects cannot explain the permeability decrease, the trend is reproduced with the correct order of magnitude by considering a chemical effect: a pore size reduction in the sample due to water adsorption at mineral surface.
AB - Hydromechanical properties of shales are complex due to the involved material structure, with the solid matrix being mainly formed by swelling clays and porosity dominated by nanometer scale tortuous voids with large aspect ratios. Intrinsic permeability of restructured Opalinus Clay (Swiss shale) brought to shallow geological storage conditions was measured with in situ brine. Under constant temperature, vertical stress, and downstream fluid pressure, steady-state flow experiments show a significant trend of permeability decrease with increasing differential (upstream minus downstream) fluid pressure, thus contradicting the conventional Darcy’s description. To interpret these experimental measurements, brine permeability is derived using a one-step self-consistent homogenization scheme based on the knowledge of material’s pore structure. While mechanical and thermal effects cannot explain the permeability decrease, the trend is reproduced with the correct order of magnitude by considering a chemical effect: a pore size reduction in the sample due to water adsorption at mineral surface.
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U2 - 10.1007/978-3-319-52773-4_31
DO - 10.1007/978-3-319-52773-4_31
M3 - Conference contribution
AN - SCOPUS:85011422333
SN - 9783319527727
T3 - Springer Series in Geomechanics and Geoengineering
SP - 273
EP - 280
BT - Advances in Laboratory Testing and Modelling of Soils and Shales, ATMSS 2017
A2 - Ferrari, Ferrari
A2 - Laloui, Lyesse
A2 - Ferrari, Ferrari
PB - Springer
T2 - International Workshop on Advances in Laboratory Testing and Modelling of Soils and Shales, ATMSS 2017
Y2 - 18 January 2017 through 20 January 2017
ER -