A major oil operator was generating 15,000 bbl of produced water per day during heavy oil production in its operation in southeastern Europe. The produced water included diluents that emulsified the oil, leaving high concentrations of asphaltenes and diesel-range organics with total suspended solids (TSS) concentrations up to 800 mg/L. Oil, grease, and emulsion content varied greatly during production. The corrosive nature of the produced water necessitated the use of 316 stainless steel construction material on the project. The operator sought a solution that would enable filtering the water to less than 10 ppm of contaminants, which would allow reinjection of the produced water for reuse in the operation.
SLB recommended that the operator include advanced media technology in the treatment train to reduce oil content from the original 2,500 ppm to less than 10 ppm. The system included three stages of decontamination:
The advanced media technology system included automatic controls to respond to fluctuations in flow rates and pressure drop. Because of the risk of corrosion posed by the produced water, anodic protection was used to maintain system integrity.
By using advanced media technology, the operator effectively and consistently removed contaminants from the produced water to achieve a 2-ppm level for reinjection use—lower than the 10-ppm level that was specified. This performance was well maintained during large fluctuations of asphaltene and diesel-range organics in free, dispersed, and emulsified phases. Inlet oil levels varied between 100 and 2,500 ppm, and the system outlet showed oil reduced to 10 ppm or less throughout use of the system.
