Synthesis and Characterization of a New Surface-Modified Nanoparticle Using Fluoroalkanoic Acids as a Wettability Alteration Agent

Abstract

Previously, condensate banking removal in gas reservoir is mitigated using chemical treatments to alter the wettability of the near-wellbore region. However, this technique performed unsatisfactorily as it reduces the surface free energy and affects the gas relative permeability negatively. Hence, alternative surface-modified nanoparticles using fluorine-based chemicals were developed as wettability alteration agents since fluorine exhibits a high degree of liquid repellency and nanoparticles introduce high surface roughness. The newly synthesized surface-modified nanoparticles were characterized using FTIR, DLS, FESEM, and TGA. FTIR results highlight the characteristic absorption of Si-O-C group at peak 1105 and 1106 cm-1 in both fluoroalkanoic acids, demonstrating that fluorochemical molecules have been successfully coated onto silica nanoparticles. Nanoparticle sizes measured by DLS reported higher value than FESEM due to agglomeration, and the DLS measurement was done in hydrodynamic conditions. TGA analysis reveals decomposition at temperature between 100 and 150°C, indicating that these surface-modified nanoparticles can be utilized in an environment below 100°C. Higher decomposition was perceived on PFNA-modified nanoparticles as a thicker coating of PFNA is shrouding the silica nanoparticles compared to PFOA. Implications of the results will path the way for future research direction in using fluorine-based surface-modified nanoparticles as wettability alteration agents.