Investigating the effects of reaction time on scaling dynamics in produced water and its implications for enhanced...

Produced water, major byproduct of oil production, presents significant environmental challenges due to its volume and toxicity. Effective management through re-injection is the most environmentally and economically viable approach, yet inorganic scale precipitation from incompatible water mixing poses a critical challenge. Compatibility investigations are essential to understand scale types and quantities before substantial investments, with reaction kinetics playing a pivotal role. This study examines the impact of reaction time on scale precipitation in produced water management, relevant to desalination processes such as pre-treatment and brine disposal. Water samples from two oil-producing fields were mixed, with field facilities allowing either immediate reinjection or 14-day retention. Precipitated scales were filtered from one container after 1 day and from another after 14 days under operational conditions. Results showed that scales filtered after 1 day exceeded 500 mg/L, while those after 14 days were below 150 mg/L, indicating over 350 mg/L of scales re-dissolved into the liquid phase. SEM-EDX analysis revealed that some scales increased in precipitation after 14 days, while others re-dissolved. These findings highlight the critical role of chemical reaction kinetics in scale precipitation, offering insights for optimizing pre-treatment and re-injection systems, enhancing scale management and environmental sustainability in produced water treatment.