Development of new silica nanoparticles/tetrapolymer core–shell structure with high thermal resistance for application in water-based drilling fluids

With the expansion of exploration and the development of the oil and gas industry, geological formation conditions are becoming increasingly complex. Currently, more than 40% of reservoirs are located in deep layers. This scenario imposes significant technical challenges and requires the development of advanced technologies for the efficient and safe exploitation of these resources. This work deals with developing core–shell nanocomposites with silica nanoparticles as the core and the tetrapolymer as the shell and the preliminary evaluation of its applications as an additive in water-based drilling fluids under thermal aging conditions. The synthesis was carried out using two different methodologies, and the formation of the structures was confirmed by Fourier transform infrared spectroscopy/far infrared spectroscopy (FTIR/FIR) and energy-dispersive spectroscopy (EDS) analysis, which showed the presence of atoms of the polymer matrix and the characteristic bonds. Thermogravimetric analysis revealed that the structures showed good thermal stability with initial degradation temperatures above 260 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis indicated morphological changes and dynamic light scattering (DLS) analysis showed a particle size range around 500 nm, with a tendency to aggregation in aqueous media. The two nanocomposites showed excellent performance in preliminary tests, improving and stabilizing the rheological properties after the aging process. The success in obtaining these hybrid structures opens up new possibilities for the development of additives to improve the performance of drilling fluids in deep and ultra-deep well environments.

Graphical abstract