Evolution of Mechanical and Hydraulic Properties in Sandstone Induced by Mineral Trapping

Abstract

In this study, evolution of mechanical and hydraulic properties in Berea sandstone with initial porosity of 20 &#37: is examined quantitatively by replicating mineral trapping process within pore spaces. The artificially accelerated mineral trapping is achieved by injecting a grout, resulting in calcite precipitation. The amount of calcite precipitated can be controlled by changing the concentrations of the grout and the total injection volume. The preliminary experiments indicate that the change of the mechanical and hydraulic properties is significant even if the calcite amount is relatively small – the values of Young’s modulus/permeability increase/decrease with increase of the calcite amount. Specifically, the permeability decreases by one order of magnitude as the initial porosity of 20 % reduces to 18 %. This intense decrease of permeability may not be able to be replicated by existing numerical models, although distribution of the calcite precipitated within rock samples should be adequately examined because uniform distribution may not be achieved.