Published: 11/04/2016
Published: 11/04/2016
A major oil and gas operator in North America implemented an EOR process in a mature field with medium-heavy oil. The EOR technologies used were polymer flooding and alkaline surfactant polymer (ASP) flooding. These techniques significantly increased production rates but resulted in highly emulsified produced water with higher concentrations of oil from the freewater-knockout outlet.
The produced water was emulsified with oils, solids, and residual polymer from the EOR process and contained 200- to 2,500-ppm oil and grease and 50- to 1,000-ppm solids, all with varying viscosities. The high levels of oil and total suspended solids (TSS) concentrations increased the consumption of chemicals to maintain production levels, reduced process efficiency, and risked plugging the reservoir formation.
Conventional filtration technologies proved to be unsuccessful at consistently treating the water to less than 10 ppm, which is the level necessary for recycling the produced water and minimizing the use of chemicals required for polymer flooding.
To meet the operator’s objectives, Schlumberger recommended a custom media technology program in a pilot trial. The program presented a robust, compact solution consisting of
The technology uses a patented oleophilic filtration media that attracts, recovers, and removes various oil types at varying concentrations, and all systems are designed per American Society of Mechanical Engineers (ASME), National Association of Corrosion Engineers (NACE), and Alberta Boilers Safety Association (ABSA) requirements for pressure vessels, instrumentation, and skids.
Using the suite of advanced media technology, the operator consistently removed up to 98% of the oil from the produced water to achieve concentrations of less than 10 ppm, even at a flow rate of 286 bbl/h [46 m3/h] during upset conditions in the upstream production process. The operator was able to reuse the decontaminated water in its polymer injection campaign, saving time and costs. Because the filtration system was easy to operate and required minimal maintenance, the operator saved additional time and internal resources.
Challenge: Decontaminate produced water emulsified with 200- to 2,500-ppm oil and grease and 50- to 1,000-ppm solids—all with varying viscosities—from the enhanced oil recovery (EOR) process implemented in a mature field with medium-heavy oil.
Solution: Deploy a customized suite of advanced media filter oil-free water technology, which uses patented oleophilic filtration media to attract, recover, and remove a range of oil types at varying concentrations.
Results: Removed oil initially at up to 2,500 ppm in the produced water to achieve oil content less than 10 ppm under upstream production process upset conditions, achieving an oil recovery rate of up to 98% and protecting the reservoir formation from plugging.
