Asphaltene precipitation significantly impacts the oil and gas industry by reducing production by depositing in pores upon decreases in pressure. Traditional preventive methods, such as squeeze treatment, require frequent and costly injections of asphaltene solvents or inhibitors (AIs) into production wells. To better maintain production, there is a substantial interest in developing asphaltene inhibitor- controlled release systems using nanoparticles to achieve long-term inhibition for up to one year. We propose an encapsulation strategy employing mesoporous silica nanoparticles and strategically designed AIs to facilitate the controlled, extended release of AIs in organic solvents including xylene and model oils.
We employed several characterization techniques, including scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, dynamic light scattering, and zeta-potential measurements. The colloidally stable sub-500 nm nanoparticles could be injected with minimal formation damage in porous sandstones. Using UV-Vis spectroscopy, we assessed the inhibitor release behavior, to design chemical structures for prolonged release. A model was used to describe the kinetics and thermodynamics of the AI adsorption/desorption dynamics on silica to predict long term performance in reservoirs. By setting a new standard in asphaltene precipitation management, this approach not only aims to improve operational efficiency and reduce costs, but also to provide fundamental concepts for long term-controlled release with advanced nanomaterials in the oil and gas industry.
