TY - JOUR
T1 - Influence of brine compositions on wetting preference of montmorillonite in rock/brine/oil system
T2 - An in silico study
AU - Ghasemi, Mehdi
AU - Shafiei, Ali
N1 - Funding Information:
The authors would like to acknowledge the financial support from Nazarbayev University for this research through a Faculty Development Competitive Research Grants Program (FDCRGP grant# 110119FD4529). The authors would like to thank three anonymous reviewers for their critical yet fair and constructive comments, which helped the authors to improve the quality of the manuscript.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/12/30
Y1 - 2022/12/30
N2 - In this paper, we investigated dependency of thin brine film stability confined between rock and hydrocarbon layer on brine solution properties in terms of salinity and anionic components. Molecular Dynamics simulation was used to investigate behavior of the system at rock/brine and brine/oil interfaces to characterize thin brine film. Here, montmorillonite, a thin water film containing different salinities (low salinity water, 5,000 ppm, and high salinity water, 70,000 ppm) of NaCl and Na2SO4, and organic components constituting 3:1 M mixture of decane and sodium decanoate were considered to represent rock, brine, and oil, respectively. High salinity brine makes the thin film more stable. Extensive repulsive electrostatic forces between Cl− anions distributed in brine film and carboxylate functional groups at the brine/oil interface impede penetration of oil components into the brine film and then their adsorption onto the clay surface. Low salinity Na2SO4 showed the most stable brine film, in which distribution of anions at the brine/oil interface prevents intrusion of oil components into the brine film. However, high salinity Na2SO4 showed strong potential in forming ionic aggregations comprising Na+ cations and anions. These ionic aggregations act as bridging agents to adhere oil constituents onto the clay slab.
AB - In this paper, we investigated dependency of thin brine film stability confined between rock and hydrocarbon layer on brine solution properties in terms of salinity and anionic components. Molecular Dynamics simulation was used to investigate behavior of the system at rock/brine and brine/oil interfaces to characterize thin brine film. Here, montmorillonite, a thin water film containing different salinities (low salinity water, 5,000 ppm, and high salinity water, 70,000 ppm) of NaCl and Na2SO4, and organic components constituting 3:1 M mixture of decane and sodium decanoate were considered to represent rock, brine, and oil, respectively. High salinity brine makes the thin film more stable. Extensive repulsive electrostatic forces between Cl− anions distributed in brine film and carboxylate functional groups at the brine/oil interface impede penetration of oil components into the brine film and then their adsorption onto the clay surface. Low salinity Na2SO4 showed the most stable brine film, in which distribution of anions at the brine/oil interface prevents intrusion of oil components into the brine film. However, high salinity Na2SO4 showed strong potential in forming ionic aggregations comprising Na+ cations and anions. These ionic aggregations act as bridging agents to adhere oil constituents onto the clay slab.
KW - Hydrocarbon layer
KW - Interfacial interactions
KW - Molecular Dynamics simulation
KW - Montmorillonite
KW - Thin brine film
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U2 - 10.1016/j.apsusc.2022.154882
DO - 10.1016/j.apsusc.2022.154882
M3 - Article
AN - SCOPUS:85138044017
SN - 0169-4332
VL - 606
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 154882
ER -