Phosphonated Polyetheramine-Coated Superparamagnetic Iron Oxide Nanoparticles for Inhibition of Oilfield Scale

Oilfield scale is one of the significant problems in hydrocarbon production in the oil and gas industry. Many research groups have attempted to develop greener chemicals to meet environmental regulations. Magnetic nanoparticles are an intriguing technology due to their multiple properties, such as size effects, surface-to-volume ratio, magnetic separation, specificity, low toxicity, and the ability to control exposure and surface chemistry. In this project, we propose a new method to remove chemicals from the produced fluids by attaching the chemicals to superparamagnetic iron oxide nanoparticles (SPIONs), allowing a facile magnetic removal and reusing and recycling. In principle, the system is fully self-contained, and no chemicals or SPIONs are discharged, reducing the overall environmental footprint. We earlier reported synthesizing and using phosphonated polyetheramines (PPEAs) as environmentally friendly and potent scale inhibitors against carbonate and sulfate oilfield scales. Herein, we report the synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with biocompatible trisodium citrate (TSC) as a stabilizer agent to avoid crystal grain growth SPIONs using a coprecipitation approach. The resultant SPIONs-TSC was further functionalized with a partially linear phosphonated polyetheramine (PPEA), as green SI, via electrostatic interaction, affording highly monodisperse SPIONs-TSC-PPEA. The synthesized SPIONs-TSC-PPEA was thoroughly characterized via various spectroscopic and analytical techniques. Moreover, to validate the proof of concept of inhibition, recovering, and recycling SPIONs-based scale inhibitors, a series of static jar tests and high-pressure dynamic tube-blocking tests at 80 bar and 100 °C under oilfield conditions were conducted. The results showed that SPIONs-TSC-PPEA gave excellent inhibition performance against the gypsum scale even when recycled four times. In addition, the morphology of the gypsum scales in the absence and presence of SPIONs-TSC-PPEA was determined using scanning electron microscopy (SEM).