Influence of Silica Surface Hydrophilicity on Adsorbed Water and Isopropanol Studied by in-situ NMR

Authors: Hyung T. Kwak, Jun Gao, Yao An, Alfred Kleinhammes, Yue Wu

Abstract:

Surface wettability is a crucial factor in oil recovery. In oil industry, the rock wettability involves the interplay between water, oil, and solid surface. Therefore, studying the interplay between adsorptions of water and hydrocarbon molecules on solid surface would be very informative for understanding rock wettability. Here we use the in-situ Nuclear Magnetic Resonance (NMR) gas isotherm technique to study competitive adsorptions of water and isopropanol, an intermediate step from hydrocarbons. This in-situ NMR technique obtains information on thermodynamic properties such as the isotherm, molecular dynamics via spin relaxation measurements, and adsorption kinetics such as how fast the system can reach thermal equilibrium after changes of vapor pressures. Using surfaces of silica glass beads, which can be modified from hydrophilic to hydrophobic, we obtained information on the influence of surface hydrophilicity on the state of surface water via obtained thermodynamic and dynamic properties.

Keywords: Competitive adsorption, nuclear magnetic resonance, wettability.

References:

[1] Forrest F. Craig, J., The Reservoir Engineering Aspects of Waterflooding. Society of Petroleum Engineers of AIME, New York, 1971.
[2] Amott, E., Observations Relating to the Wettability of Porous Rock. 1959, Society of Petroleum Engineers. p. 7.
[3] Donaldson, E.C., et al., Equipment and procedures for fluid flow and wettability tests of geological materials. 1980: United States.
[4] Brown, R.J.S. and I. Fatt, Measurements Of Fractional Wettability Of Oil Fields' Rocks By The Nuclear Magnetic Relaxation Method, in Fall Meeting of the Petroleum Branch of AIME. 1956, Society of Petroleum Engineers: Los Angeles, California. p. 4.
[5] Devereux, O.F., Effect of Crude Oil on the Nuclear Magnetic Relaxation of Water Protons in Sandstone. Nature, 1967. 215(5101): p. 614-615.
[6] Hsu, W.-F., X. Li, and R.W. Flumerfelt, Wettability of Porous Media by NMR Relaxation Methods, in SPE Annual Technical Conference and Exhibition. 1992, Society of Petroleum Engineers: Washington, D.C. p. 11.
[7] Daughney, C.J., T.R. Bryar, and R.J. Knight, Detecting Sorbed Hydrocarbons in a Porous Medium Using Proton Nuclear Magnetic Resonance. Environmental Science & Technology, 2000. 34(2): p. 332-337.
[8] Looyestijn, W.J. and J. Hofman, Wettability-Index Determination by Nuclear Magnetic Resonance. SPE Reservoir Evaluation & Engineering, 2006. 9(02): p. 146-153.
[9] Song, Y., et al., Hydrophilic and Hydrophobic Characteristics of Reservoir Rocks Quantified by Nuclear Magnetic Resonance-Detected Water Isotherms. The Journal of Physical Chemistry C, 2019. 123(10): p. 6107-6113.
[10] Zhao, L., et al., Reversible State Transition in Nanoconfined Aqueous Solutions. Physical Review Letters, 2014. 112(7): p. 078301.