Water Reuse Focus for Central Oklahoma
Enhanced oil and gas recovery (fracturing) techniques and water go hand in hand. Current pressures including limited fresh water sources, transportation, fracturing volume requirements, and disposal costs and restrictions are driving the development of new water management strategies. Recycling and managed biologic treatment of surface water is proving to be a cost-effective, more environmentally sound solution for produced water.
The facility provides surface water management for the surrounding area and has a nominal treatment capacity of 30,000bbl/d. The key elements for treatment include pre-treatment for oil recovery and solids separation, biological treatment for management of dissolved constituents, and storage for fracturing activities. The use of biological treatment is broadly applied in a wide range of wastewater treatment applications; however, its use is just emerging in the oilfield. With proper process design and aeration equipment selection, a robust, cost effective solution is now available and is being demonstrated at this and other oil and gas facilities.
Sourcing suitable water for initial injection and high operating cost to store and chemically treat produced water are two reasons why the industry is seeking more economical and environmentally sound solutions for produced water management. Greater reuse of produced water conserves limited fresh water resources, reduces handling and hauling costs, and drastically reduces the volume of water injected underground for disposal.
Unfortunately, high salinity and dissolved solids concentrations in produced water severely challenge traditional aeration techniques. Mechanical surface aeration consumes a lot of energy, suffers shortened equipment life through fouling and corrosion, and requires awkward and hazardous on-water maintenance. Their configuration also limits the ability to drawdown the pit and restricts the use of the stored water for fracturing needs. Subsurface diffused aeration provides improved pit use but also suffers shortened equipment life and losses in operating efficiency.
EDI, with its extensive expertise in biological treatment and aeration including over 7000 installations worldwide, engineered and delivered a turnkey solution that specifically addresses the unique challenges presented by produced water treatment.
EDI’s solution incorporated:
EDI also provided a customized front-to-back maintenance service package to assure the aeration system is always in top operating condition.
System commissioning was completed in July 2017 and is expected to begin treating produced water immediately. Results will be compiled over time to document the performance of the system; however, similar operating facilities in the region have already demonstrated the treatment and cost metrics for the facility. EDI’s advanced design provides a reduction in energy use by more than 50% compared to alternate aeration techniques, and the installed solution reduces the capital and O&M costs for the aeration equipment to a few cents per barrel of water treated. The anticipated project term for this facility is quite long; however, even for the usual 2 – 5 year project life, a significant payback and short return on investment are big wins for the customer.
Location: Central Oklahoma
Project Type: Industrial
Completion Date: July 2017