Decentralized Produced Water Treatment Systems for Remote Energy Assets, a Conceptual Design Framework

Produced water (PW) is the largest by-product of oil and gas operations and presents significant management challenges for remote energy assets, where centralized treatment infrastructure is often impractical due to logistical, energy, and environmental constraints. This review proposes a conceptual design framework for decentralized PW treatment systems tailored to remote onshore and offshore operations. The framework emphasizes modular, scalable, and adaptable treatment units capable of addressing the variable physicochemical composition of PW, including high salinity, hydrocarbons, heavy metals, and naturally occurring radioactive materials (NORM). Treatment trains integrate physicochemical processes such as gravity separation, flotation, adsorption, membrane filtration, and advanced oxidation with bio-based polishing systems including biofilm reactors, constructed wetlands, and algal-bacterial consortia. This hybrid approach ensures robust contaminant removal, operational flexibility, and resilience under fluctuating flow rates and water quality typical of remote operations. The framework also considers off-grid energy solutions, leveraging renewable sources such as solar and wind to reduce operational carbon footprints, and incorporates resource recovery pathways, including nutrient extraction, biomass utilization, and salt recovery, supporting circular water management principles. Digital monitoring, automation, and AI-driven process optimization are highlighted as key enablers for real-time control, predictive maintenance, and adaptive operation, reducing risks associated with system failure in isolated locations. Environmental and safety considerations, including minimization of land use, chemical inputs, and residual waste management, are integrated into the design to ensure sustainable operation. Overall, the proposed conceptual framework demonstrates that decentralized PW treatment systems can provide a flexible, energy-efficient, and environmentally responsible solution for water management in remote energy assets. By combining modular engineering, hybrid treatment strategies, and digital intelligence, these systems enable fit-for-purpose water reuse, reduce dependence on freshwater resources, and enhance operational resilience, supporting sustainable and circular water management practices in water-stressed and isolated operational settings.