Produced Water Treatment

The treatment of effluents of oil and gas operations can sometimes be impacted by the presence of produced polymer. This chapter highlights current technologies and developments. Depending on the polymer concentration, the viscosity of the produced effluents, and the water treatment facilities in place, it might be necessary in some cases to degrade the polymer to maintain acceptable cleaning performance. A question that often arises is the possible impact of polymers on surface facilities during oil/water separation and, afterward, on the water treatment facilities. The chapter discusses these aspects, and outlines possible solutions. The produced water composition will vary over the life of the field due to factors and interventions such as water injection, reservoir stimulation, introduction of chemicals, bacterial activity, enhanced oil recovery (EOR) techniques, and so on. Equipment to remove oil and solids relies on different principles: gravity separation, gas flotation, cyclonic separation, filtration, and centrifuge separation.