Determination of the spatial distribution of wetting in the pore networks of rocks

Gaetano Garfi; Cédric M John; Maja Rücker; Qingyang Lin; Catherine Spurin; Steffen Berg; Samuel Krevor

doi:10.1016/j.jcis.2021.12.183

Determination of the spatial distribution of wetting in the pore networks of rocks

J Colloid Interface Sci. 2022 May:613:786-795. doi: 10.1016/j.jcis.2021.12.183. Epub 2022 Jan 10.

Authors

Gaetano Garfi¹, Cédric M John¹, Maja Rücker², Qingyang Lin³, Catherine Spurin⁴, Steffen Berg⁵, Samuel Krevor⁶

Affiliations

¹ Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
² Department of Mechanical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, the Netherlands; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
³ State Key Laboratory of Clean Energy Utilization, State Environmental Protection Engineering Center for Coal-Fired Air Pollution Control, Zhejiang University, Hangzhou 310027, China; Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
⁴ Department of Energy Resources Engineering, Stanford University, Stanford, CA, United States; Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
⁵ Shell Global Solutions International B.V., Grasweg 31, 1031HW Amsterdam, the Netherlands; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom; Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
⁶ Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom. Electronic address: s.krevor@imperial.ac.uk.

PMID: 35074705
DOI: 10.1016/j.jcis.2021.12.183

Abstract

Hypothesis: The macroscopic movement of subsurface fluids involved in CO₂ storage, groundwater, and petroleum engineering applications is controlled by interfacial forces in the pores of rocks. Recent advances in modelling these systems has arisen from approaches simulating flow through a digital representation of the complex pore structure. However, further progress is limited by difficulties in characterising the spatial distribution of the wetting state within the pore structure. In this work, we show how observations of the fluid coverage of mineral surfaces within the pores of rocks can be used as the basis for a quantitative 3D characterisation of heterogeneous wetting states throughout rock pore structures.

Experiments: We demonstrate the approach with water-oil fluid pairs on rocks with distinct lithologies (sandstone and carbonate) and wetting states (hydrophilic, intermediate wetting, and heterogeneously wetting).

Findings: Fluid surface coverage the within rock pores is a robust signal of the wetting state across varying rock types and wetting states. The wetting state can be quantified and the resulting 3D maps can be used as a deterministic input to pore scale models. These may be applied to multiphase flow problems in porous media ranging from soil science to fuel cells.

Keywords: Digital rocks; Wetting.