Network modelling of strong and intermediate wettability on electrical resistivity and capillary pressure

A network model that investigates electrical resistivity and capillary pressure curves of oil/water/rock systems for a full̄ooded cycle (primary drainage, imbibition and secondary drainage) is presented. This model uses a realistic pore geometry in the form of a grain boundary pore (GBP) shape and pore constrictions. The model also incorporates pore-scale displacement mechanisms and pore-scale wettability alteration that are physically based. A range of contact angles (from 0 to 180°) has been investigated. A detailed description of wettability at the pore scale was simulated to allow both waterand oil-wet regions existing within a single pore. Our numerical simulated results show experimentally observed non-linear trends in double-logarithmic plots of resistivity index vs water saturation. Furthermore, our results show that contact angle hysteresis, which leads to di€erent pore scale physics (e.g., snap-o€ vs piston-like displacement), reveals hysteresis observed in both electrical resistivity and capillary pressure curves. Ó 2001 Elsevier Science Ltd. All rights reserved.