The Mechanical Behaviour of an Artificial Siltstone

Sedimentary rock deposits such as siltstone have been attracting interest due to their potential to store and control the movement of sequestered CO₂. An understanding of weak caprocks is required to guarantee the safety of CO₂ geo-sequestration projects where weak rocks are encountered. The cost and challenge of obtaining intact samples of weak caprocks from depths relevant to potential geo-sequestration targets has resulted in relatively little data on their mechanical behaviour being available. This paper describes the manufacture and characterisation of artificial siltstones, with properties typical of weak rocks, at stress levels relevant to geo-sequestration. It is shown that the artificial siltstones with properties typical of weak rocks can be simply produced from mixtures of sand, feldspar fines, plaster and water.