Treatment of produced water from oil and gas wells using crossflow ultrafiltration membranes
Santos, Susan Moore
Master of Science
Currently employed methods for treating produced water do not consistently meet regulatory limits on oil and grease discharge concentrations. Experiments with different produced waters using tubular, crossflow, ultrafiltration membranes demonstrated that oil and grease concentrations less than 14 mg/l (well below current regulatory limits) could be achieved. Ultrafiltration experiments on produced water and model oil emulsions demonstrate that virtually all colloidal organic materials are rejected by the membrane, while dissolved organic materials pass through it. The membrane rejects precipitated iron and suspended solids. Permeate flux behavior and the effectiveness of different cleaning procedures vary significantly among produced waters. Generalizations on permeate flux performance during ultrafiltration treatment of produced water do not appear to be warranted. Permeate flux ranged from 73 to 306 l/m$\sp2$-hr depending on the produced water source and the cleaning procedures. Pilot studies on specific produced waters may be necessary to insure this process' applicability.