Produced Water Management Practices in Indigenous Oil Companies: A Review of Treatment and Disposal Approaches
Produced water refers to water being brought to the surface during production from subsurface reservoirs. It is typically the largest-volume by-product or waste stream associated with oil and gas exploration and production. Produced water has a complex composition of total dissolved salts, dissolved hydrocarbons, suspended solids, and both soluble and insoluble organic compounds, which can pose significant risks to the marine environment if discharged without adequate treatment. Produced water management constitutes a major challenge for indigenous producing companies, primarily due to limited capital expenditure and restricted access to advanced technologies, which significantly influence the selection and performance of management strategies. Currently, the most widely adopted method for disposal among producing companies is deep well injection, which is reliable for disposing large volumes of water with minimal environmental impact. However, the cost to drill and complete a dedicated deep injection well typically ranges from about USD 1–10 million onshore (and significantly higher offshore), depending on various factors, representing a substantial financial burden for indigenous companies, particularly those at early stages of production. This paper reviews produced water treatment, reuse, and disposal technologies adopted by indigenous oil companies and presents sustainable alternative practices considering national regulatory requirements, economic constraints, and recent technological advances. The study is based on a review of published literature, industry reports, regulatory guidelines, and field practice documentation related to produced water management in oil fields. Treatment methods were classified into physical, chemical, biological, and advanced technologies and evaluated based on treatment efficiency, operating cost, footprint, and ease of maintenance. Disposal and reuse options, including reinjection, overboard discharge, irrigation, and limited industrial reuse, were also reviewed. This paper offers practical guidance for production engineers, facilities engineers, and environmental managers by highlighting fit-for-purpose produced water management strategies that balance performance, cost, and regulatory compliance, thereby supporting practical, scalable, and locally adaptable solutions for indigenous oil and gas operations.