Prediction of Interface Shape and Capillary Pressure in an Idealized Pore Structure: Effect of Grain Size

Accurate prediction of the capillary pressure of small volumes of liquid in porous media is complicated by the complex geometries and the nonlinearity of the governing equations. Interface shapes depend on the reservoir characteristics such as the wetting properties and rock geometries. Here we consider an idealized situation in which a small volume of liquid surrounds an upright cylindrical grain on a flat substrate and predict the shape that the liquid takes and its capillary pressure. We validate two approximations for the capillary pressure against accurate numerical simulations. We propose the second of these as a predictive tool for reservoir engineering