Nanometer-Scale Deformations of Berea Sandstone under Moisture-Content Variations

摘要: Sandstone mechanical stability is of key concern in projects involving injections CO2 sandstone geological reservoirs, for the purpose long-term storage. We developed a method to measure nanometer-scale deformations sandstones real time. demonstrate that Berea sandstone, when hydrated, changes dimensions with relative deformation order 10^(-4). If moisture content increases, samples exhibit an extension and if decreases then shrink. also discover that, immediately after exposure water, temporarily shrinks, just few seconds, which slow begins, continues until about half fluid evaporates. Such shrinkage followed by has been observed sample was exposed acetone, Mineral Spirits or Vacuum Oil. The results are obtained using high-resolution nano-positioner technique and, independent experiments, confirmed coda wave interferometry.