(772c) Impact of Brine/CO2 Exposure on the Transport and Mechanical Properties of Mt Simon Rock Samples

When sandstone rocks are exposed to CO₂-saturated brine their transport and mechanical properties can change due to brine/CO₂-induced chemical reactions. The present study investigates the change in the flow-through characteristics, porosity and the deformation of Mt Simon rock samples caused by exposure to brine/CO₂. The subsamples, extracted from the Mt. Simon sandstone, were first characterized for their mechanical and transport properties, and then aged in CO₂-saturated brine at pressures of 2500 psi and temperature of 50⁰C for one week. Following that, tests were carried out to measure the change in transport and mechanical properties of the rock. The changes in porosity were measured by the helium porosimetry method. The alteration in pore size distribution and flow-through characteristics were determined by the flow permporometry method. The changes in the brine composition were measured by ion chromatography. In addition, a brine-saturated Mt. Simon sandstone core was aged in a specialized core holder while the deformation of the core during CO₂ invasion was detected in situ via an array of strain gauges.