Oil and Gas Produced Water Management: A Review of Treatment Technologies, Challenges, and Opportunities

Produced water (PW), which could be a complex mixture of different organic and inorganic compounds (mostly salts, minerals, and oils), is a major wastewater generated during oil/gas production due to increased oil and gas production, particularly with usability of shale oil/gas reserves, the volume of this effluent is increasing around the world, and as a consequence, its discharge to the environment is one of the global concerns. There are various physical and chemical methods to treat the PW. Each method has its own advantages and disadvantages when used for offshore or onshore units. However, comprehensive and deep-understanding of each issue can provide a guideline for better and more practical solutions. In this work, various physical and chemical treatment methods as well as membrane separation technology are reviewed based on the recent literature. Moreover, challenges and opportunities of each method applied to PW treatment are comprehensively discussed. Furthermore, alternatives for reuse of treated PW are suggested and discussed.