The interfacial properties of clay-coated quartz at reservoir conditions
Abstract
Shale interfacial properties are important for CO2 geo-sequestration and CH4 recovery in shale formation. In this work we use a newly-developed and well-defined shale model (i.e. a clay-coated quartz) to systematically evaluate the influence of kaolinite and montmorillonite, as primary constituents of shales, on CO2 shale-wettability, and shale-CO2, shale-CH4, and shale-water surface energies. Specifically, we measure CO2 wettability of clay-coated quartz and the related CO2-brine and CH4–brine interfacial tensions at various pressures and temperatures. We calculate the surface free energies of the clay-coated quartz versus CO2 and CH4 using Neumann's equation. The results demonstrate that clay coating leads to a less hydrophilic surface at a low temperature (i.e. 300 K), while it renders the surface more hydrophilic at a high temperature (i.e. 353 K); however, clay coating has only a small influence on the quartz-CO2 and quartz-CH4 surface energies. In addition, higher CO2 pressures always result in less water-wet surfaces for clean, kaolinite-coated and montmorillonite-coated quartz samples at the temperatures tested (i.e. 300 K and 353 K). Moreover, higher CO2 and CH4 pressures lead to smaller mineral-CO2 and mineral-CH4 surface energies, respectively. An increase in temperature shows a complicated effect, i.e. it increases the surface energies of mineral-CO2 while it reduces those of mineral-CH4 (slightly) and clay-coated quartz-brine systems. For similar pressure and temperature values, the surface energies of mineral-CO2 system are always smaller than those of the corresponding mineral-CH4 systems. The results can aid the predictions of CO2 storage capacity, leakage risk assessments, and CH4 recovery.
Keywords
CO2 and CH4 wettabilities, Kaolinite-coated quartz, Mineral-CH4 and mineral-brine surface energies, Mineral-CO2, Montmorillonite-coated quartz, Carbon dioxide, Coatings, Hydrophilicity, Interfacial energy, Kaolinite, Quartz, Reservoirs (water), Risk assessment, Temperature, Wetting, Geo sequestrations, High temperature, Hydrophilic surfaces, Interfacial property, Low temperatures, Pressure and temperature, Reservoir conditions, Surface free energy, Shale
Document Type
Journal Article
Date of Publication
1-1-2020
Publication Title
Fuel
Publisher
Elsevier
School
School of Engineering
RAS ID
30247
Funders
Funding information available at: https://doi.org/10.1016/j.fuel.2019.116461
Copyright
subscription content
Comments
Pan, B., Gong, C., Wang, X., Li, Y., & Iglauer, S. (2020). The interfacial properties of clay-coated quartz at reservoir conditions. Fuel, 262, Article 116461. https://doi.org/10.1016/j.fuel.2019.116461