Does use of Chlorine Dioxide in Produced Water Treatment improve Oil Recovery?
This is the age old question that PureLine’s Brian Wrenn is out to answer. For years our customers have suggested that when chlorine dioxide is used they harvest more oil from produced water. But PureLine had never found a study proving or disproving
oil recovery amounts. Dr. Brian Wrenn is conducting the study which is expected to be completed in the spring of 2016.
PureLine will test the effects of chlorine dioxide on the performance of a produced water treatment system for an operator in Windsor, CO. Suspected contaminants in the produced water and flowback that are treated in the facility include: bacteria, sulfides, suspended solids, oil, and gels. The expected benefits of chlorine dioxide treatment include: elimination of bacteria and sulfides from treated water, improved removal of suspended solids, and improved recovery of oil. The effects of treatment will be evaluated by comparing the quality of the effluent during treatment to its quality under normal operating conditions.
In this study treatment runs (e.g., chlorine dioxide) will alternate with control runs (i.e., normal operation). Each treatment and control run will last three days. The residual concentration of chlorine dioxide (treatment runs only) and the turbidity will be measured hourly throughout each run, and the concentrations of residual oil (oil and grease by EPA Method 1664A), and bacteria (APB and SRB) will be measured at least twice during each run. The concentrations of total sulfides and total iron will be measured intermittently. All measurements will be made on samples collected from the effluent of the weir tank. Turbidity will also be measured after filtration.
Two treatments will be tested: chlorine dioxide alone and chlorine dioxide plus demulsifier. In both cases, the target residual chlorine dioxide in the effluent from the weir tank will be about 2 mg/liter, and the effluent pH will be maintained above 6. The demulsifier will be provided by a Service Company and applied at a dose recommended by them. All chemical treatments will be provided immediately before the inlet to the weir tank.