Numerical investigation of oil-water drainage and imbibition in digitized sandstones

Ingrain Inc. Houston, TX 77027, USA

^a Corresponding author: xiaobo@ingrainrocks.com

Received: 26 January 2015
Accepted: 21 July 2015

Abstract

We simulated the primary drainage and first imbibition processes in a numerical porous-plate experiment using a lattice-Boltzmann based pore scale simulator. The pore space representations of the Berea, Fontainebleau and Bentheimer sandstones were obtained by high resolution micro-CT and subsequent segmentation. The pore body and throat distributions were identified using an open-map based method. The rock surface was assumed completely water wet. The capillary pressure as function of water saturation and the oil and water distributions were investigated for different geometries represented by the different sandstone samples. The calculated residual oil saturation after imbibition compares well with recently published high quality laboratory data. The dependence of the residual oil saturation on the initial oil saturation was calculated and the results are consistent with published experimental data and correlations. Finally the drainage and imbibition processes were calculated for several Fontainebleau samples with different porosity. It was found that the residual oil saturation decreases with porosity and the variation agrees well with published experimental data.