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Wettability Alteration Mechanism of Calcite Surface: Molecular Dynamics Simulation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 81st EAGE Conference and Exhibition 2019, Jun 2019, Volume 2019, p.1 - 5
Abstract
Four representative crude oil components with different polarities, acetic acid, pyridine, toluene and hexane were selected to study the wettability alteration mechanism of calcite surface. The wettability alteration mechanism was investigated through adsorption interaction and intermolecular interaction. Simulation results indicated that the adsorption strength of four crude oil components is acetic acid> pyridine>toluene>hexane. Electrostatic force plays an important role in polar components adsorption, while van der Waals force is dominant in nonpolar components adsorption. For intermolecular interaction, the smaller the polarity difference, the greater the interaction intensity. The interactions among non-polar components are mainly van der Waals force, while that of polar components are primarily electrostatic force. On water-wet calcite surface, the acetic acid-pyridine-water-toluene-hexane adsorption sequence is formed. This paper reveals the wettability alteration mechanism of calcite surface, which provides theoretical support for targeted adjustment of carbonate reservoir wettability.