Modelling of simulated reservoir sandstones clay precipitation within

The purpose of this study was to investigate whether a previously developed computer model, named Pore-Cor, could simulate the subtle changes in void space dimensions which occur during the artificial deposition of small amounts of illite and kaolinite within Fontainebleau sandstone. Clay precipitation was carried out by placing a sandstone plug in a gold capsule, with an aluminosilicate gel, and treating the plug hydrothermally with potassium hydroxide solution. Using experimental conditions of 350°C and 1.0 kbar (100 MPa), illite, illite-smectite and kaolinite were precipitated in parts of the sandstone void space with morphologies similar to those of authigenic clay minerals in sandstone petroleum reservoirs. Mercury intrusion curves were then measured for the untreated and clay precipitated sandstones. The Pore-Cor package simulated these intrusion curves, and generated void space models of the correct porosity. By this means, subtle changes in void space dimensions and connectivity could be identified, which give rise to large changes in permeability. Copyright