Modeling imbibition coreflooding in heterogeneous cores with sub-core scale hysteresis

• Published in: Advances in water resources 2022-06, Vol.164, p.104214, Article 104214
• Main Authors: Anto-Darkwah, Evans, Rabinovich, Avinoam
• Format: Article
• Language: English
• Subjects: Capillary heterogeneity; Coreflooding; Hysteresis; Imbibition; Land model; Sub-core scale
• ISSN: 0309-1708; 1872-9657
• DOI: 10.1016/j.advwatres.2022.104214

Coreflooding experiments with computed tomography imaging are becoming common practice. They allow to investigate the sub-core scale properties such as relative permeability (kr) and capillary pressure (Pc), and to construct multiphase flow models that not only capture the core average flow, but also the flow on the sub-core (millimeter) scale. This work presents two-phase flow models of imbibition coreflooding in two heterogeneous core samples which underwent drainage and imbibition experiments, as part of a previous investigation. The models incorporate hysteresis in two approaches: global and sub-core. The latter includes unique Pc and kr for each grid block of the core depending on the turning point and residual saturations measured in the experiments. The simulation output of grid-block (sub-core) saturation distribution is compared to the experimental data. Results show that the sub-core hysteresis model matches the experiments more accurately than the global model. This is particularly important for the core with a higher degree of heterogeneity in which the global hysteresis model shows large errors while the model incorporating sub-core hysteresis is significantly more accurate. •Models of CO2-water imbibition coreflooding in two core samples are compared to experiments.•Hysteresis of Pc and kr is modeled in two ways: Global and a novel sub-core approach.•Sub-core hysteresis involves unique Pc and kr for each gridblock measured saturation.•Sub-core hysteresis model matches experiments more accurately than the global model.