loading page

Incorporation of Sub-Resolution Porosity into Two-Phase Flow Models with a Multiscale Pore Network
  • +1
  • Branko Bijeljic,
  • Ying Gao,
  • Martin Julian Blunt
Imperial College London

Corresponding Author:[email protected]

Author Profile
Branko Bijeljic
Imperial College
Author Profile
Ying Gao
Shell Global Solutions International B.V.
Author Profile
Martin Julian Blunt
Imperial College
Author Profile


Porous materials, such as carbonate rocks, frequently have pore sizes which span many orders of magnitude. This is a challenge for models that rely on an image of the pore space, since much of the pore space may be unresolved. There is a trade off between image size and resolution. For most carbonates, to have an image sufficiently large to be representative of the pore structure, many fine details cannot be captured. In this work, sub-resolution porosity in X-ray images is characterized using differential imaging which quantifies the difference between a dry scan and 30 wt\% KI brine saturated rock images. Once characterized, we develop a robust workflow to incorporate the sub-resolution pore space into network model using Darcy-type elements called micro-links. Each grain voxel with sub-resolution porosity is assigned to the two nearest resolved pores using an automatic dilation algorithm. By including these micro-links with empirical models in flow modeling, we simulate single-phase and multiphase flow. By fine-tuning the micro-link empirical models, we achieve effective permeability, formation factor, and drainage capillary pressure predictions that align with experimental results. We then show that our model can successfully predict steady-state relative permeability measurements on a water-wet Estaillades carbonate sample within the uncertainty of the experiments and modeling. Our approach of incorporating sub-resolution porosity in two-phase flow modeling using image-based multiscale pore network techniques can capture complex pore structures and accurately predict flow behavior in porous materials with a wide range of pore size.
14 Oct 2023Submitted to ESS Open Archive
16 Oct 2023Published in ESS Open Archive