From Pore Blockage to Flow Assurance: An Amine-Functionalized Nanofluid Strategy for Asphaltene Management Via Wettability and Aggregation Control

Abstract

Summary Asphaltene precipitation and deposition in reservoir pores pose a serious challenge to oil recovery efficiency by reducing permeability and fluid mobility. To address this challenge in this study, we introduce an amine-functionalized silica nanofluid (0.8 wt%), evaluate its dynamic performances, and elucidate the underlying mechanism through an integrated approach combining multistage flooding experiments and molecular dynamics (MD) simulations. The experimental results demonstrate that soaking with the developed nanofluid successfully mitigates permeability damage caused by asphaltene deposition: The permeability of the core sample after asphaltene deposition was 25.98 md; this increased to 36.03 md after being soaked in the nanofluid. This enhancement stemmed from two key mechanisms, which are wettability modification caused by the disjoining pressure of nanoparticles and the surface charge interactions among nanoparticles/rocks/asphaltene molecules, as well as the redispersion of asphaltene aggregates. These two aspects collectively alleviated pore throat obstructions. On a molecular level, MD simulations revealed that nanoparticles inhibited asphaltene aggregation by weakening “T-shaped” stacking or offset stacking interactions, thereby enhancing solvent-accessible surface area (SASA). These effects were driven by van der Waals forces, hydrogen bonding, and electrostatic interactions, which facilitated surface charge redistribution and promoted asphaltene solubilization. In all, the combined experimental and simulation results provided a comprehensive mechanistic understanding of how nanofluids restored reservoir permeability via wettability and aggregation control. This study may highlight the promise of functionalized nanofluids as an effective and sustainable solution for asphaltene management.