A review of treatment technologies for produced water in offshore oil and gas fields

Offshore oil and gas production is increasingly growing popular globally. Produced water (PW), which is the largest byproduct of oil and gas production, is a complex mixture of dissolved and undissolved organic and inorganic substances. PW contributes considerably to oil pollution in the offshore petroleum and gas industry owing to the organic substances, which mainly include hydrocarbons; this is a major concern to researchers because of the long-term adverse effects on the ecosystem. Since the development of offshore petroleum and gas industry, the PW treatment process has been classified into pretreatment, standard-reaching treatment, and advanced purification treatment based on the characteristics of PW and has been coupled with the environmental, economic, and regulatory considerations. The mechanism, design principle, application, and development of conventional technologies for PW treatment, such as gravity and enhanced gravity sedimentation, hydrocyclone, gas flotation, and medium filtration, are summarized in this study. Novel methods for further application, such as tubular separation, combined fibers coalescence, and membrane separation, are also discussed. Enhancement of treatment with multiple physical fields and environmentally friendly chemical agents, coupled with information control technology, would be the preferred PW treatment approach in the future. Moreover, the PW treatment system should be green, efficient, secure, and intelligent to satisfy the large-scale, unmanned, and abyssal exploration of offshore oil and gas production in the future. (C)2021 Elsevier B.V. All rights reserved.

Automated summary

Offshore oil and gas production has led to the increase in popularity of produced water (PW), the largest byproduct of this industry. PW, a complex mixture of organic and inorganic substances, contributes significantly to oil pollution and has long-term adverse effects on the ecosystem. Current PW treatment methods combine traditional technologies with emerging methods, with a focus on enhancing treatment with environmentally friendly chemical agents and information control technology to create a green, efficient, secure, and intelligent PW treatment system for future offshore oil and gas production.