Basement Configuration and its Impact on Permo- Triassic Prospectivity in Kuwait

To better assess the performance of deep geological storage of high activity radioactivity waste under the temperature changes due to the heat emitted by exothermic wastes, an investigation of the thermal pressurization in the Opalinus claystone has been conducted. Thermal pressurization is a pore pressure increase that occurs in low permeability rocks submitted to temperature elevation. It is due to the significant difference between the thermal dilation coefficient of water (w) and that of the solid phase (  s), with w >>  s. Since water is not free to expand in undrained (or poorly drained in-situ conditions in low permeability rocks), temperature elevation results in the build up of a thermal pore pressure and of a decrease of the effective stress in the rock mass. These effects may have some negative consequence on the rock permeability properties, in particular due to possible induced fractures and rock damage. This problem was one of the main concerns of the European TIMODAZ project (2006 – 2010), devoted to thermal damage in shales in the framework of radioactive waste disposal.