A green nanocomposite suppresses asphaltene precipitation in carbonates via multiscale evaluation

Abstract

Asphaltene precipitation in carbonate reservoirs presents a significant flow assurance challenge. This study investigates a novel ZnO/SiO₂/xanthan/eucalyptus nanocomposite (NCs) for inhibiting asphaltene deposition. A multiscale analysis was employed, incorporating adsorption isotherms, atomic force microscopy (AFM). and core-flooding under realistic reservoir conditions (90 °C, up to 3700 psi). Adsorption isotherm analysis confirmed that the Langmuir model provided the best data fit, indicating monolayer adsorption with a high capacity (Qm = 185.2 mg/g). Interfacial tension (IFT) measurements demonstrated NCs altered the IFT-pressure slope by 45.71%, indicating enhanced inhibition. AFM analysis revealed NCs significantly reduced surface roughness, decreasing average roughness (Ra) from 56.70 to 11.42 nm. Core-flood experiments confirmed NCs mitigated permeability impairment by over 50% and reduced asphaltene precipitation by up to 4.00 wt.% during natural depletion. The results demonstrate that the synthesized NCs are a highly effective inhibitor for mitigating asphaltene-related formation damage in carbonate reservoirs.