Eco-Friendly Scale Inhibition Strategies for Produced Water Management in Enhanced Oil Recovery: A Comprehensive Review

Mineral scale formation remains a major challenge in the management of produced water during enhanced oil recovery (EOR) operations. Although conventional scale inhibitors such as phosphonates and polycarboxylates are effective, they are becoming increasingly undesirable due to their limited biodegradability and long-term environmental persistence. This review critically examines recent advances in environmentally friendly scale inhibition strategies, including biodegradable polymers, plant-based additives, nanostructured materials, and hybrid formulations. Particular emphasis is placed on their performance under the high-temperature and high-salinity conditions characteristic of EOR systems as well as their compatibility with polymers and surfactants used in chemical flooding processes. The mechanisms of scale control─such as nucleation delay, crystal distortion, particle dispersion, and surface passivation─are discussed based on laboratory investigations and reported field-scale applications. In addition, the review highlights the growing role of data-driven control strategies, predictive dosing, and digital monitoring in optimizing inhibitor deployment. Field-scale evidence from the literature indicates that eco-friendly and nanotechnology-enhanced inhibitors can reduce scaling-related downtime by approximately 20–40% while simultaneously decreasing chemical consumption by 15–30% under harsh EOR conditions. Overall, this work provides a structured framework linking environmental sustainability with materials innovation, offering guidance for the development of next-generation scale inhibitors that satisfy both operational demands and regulatory requirements in modern petroleum engineering.