Recyclable polyaspartate-coated magnetic nanoparticles for sustainable control of calcite and barite scales in oilfield operations

Scale formation is a major challenge in hydrocarbon production, leading to decreased efficiency, equipment damage, and increased operational costs. Conventional chemical inhibitors used to prevent scaling are often non-recyclable and generate continuous chemical discharge, raising environmental concerns. In this study, a green, recyclable nanocomposite composed of a magnetite core coated with trisodium citrate and polyaspartate (Fe 3 O 4 @TSC@PASP) was developed for sustainable control of calcite (CaCO 3 ) and barite (BaSO 4 ) scales. Static jar tests show that Fe 3 O 4 @TSC@PASP achieves complete calcite inhibition at ≥20 ppm and exhibits performance trends that closely match free PASP when normalized to the active-polymer dose. Dynamic tube-blocking tests at 100 °C and 1000 psi further confirm effective scaling suppression for 60 min at 50 ppm, demonstrating that immobilization of PASP on a magnetic carrier preserves its intrinsic inhibitory function while enabling recyclable deployment not achievable with free PASP. SEM imaging revealed pronounced distortion of calcite and barite morphologies, while calcium-compatibility assessments confirmed high stability across salinity and Ca 2+ levels relevant to field environments. The nanocomposite retained full inhibition efficiency over four magnetic recovery cycles, confirming its technical feasibility for reuse. This work introduces a distinct design strategy in which PASP is immobilized on a magnetically responsive platform, providing mechanistic insight into polymer–nanoparticle synergy and establishing a practical pathway toward recyclable, environmentally responsible scale-management technologies for the energy sector. • A recyclable Fe₃O₄@TSC@PASP inhibitor is developed for oilfield scale control. • The inhibitor achieves complete calcite inhibition at ≥20 ppm under static conditions. • The material inhibits calcite and barite at 50 ppm in dynamic HPHT tests. • Full inhibition efficiency is retained over four magnetic reuse cycles. • A phosphorus-free formulation supports greener oilfield operations.