A triple play for CETCO oilfield services - treating hydrostatic test water
CETCO Oilfield Services was selected to treat and discharge approximately 150,000 barrels of hydrostatic test water in Houston, Texas. The water was treated and discharged into a nearby stream under a National Pollutant Discharge Elimination System (NPDES) permit from the State of Texas.
The permit also required that there be no discharge of floating solids or visible foam, no discharge of visible oil, and the discharge point to be above the stream’s water level for aeration of the treated water.
The hydrostatic test water was contained in three separate storage tanks located on a tank farm in east Houston. The hydrotest water contained among other contaminants, oil and grease, COD, TOC, and a yellow organic dye used during hydrostatic tests of pipelines. CETCO’s equipment was set up onsite next to each storage tank. The discharge point was a stream that flowed through the facility’s property and was located nearly 250 feet from the first tank. CETCO personnel constructed a pipeline to carry the clean water from the treatment equipment at each tank to the discharge point.
The first tank contained approximately 98,000 barrels of hydrotest water. The tank, now scheduled for repair, held the water for nearly 7 years prior to CETCO’s arrival. The fluid was pumped directly from the storage tank to CETCO’s onsite equipment for treatment. A unique challenge was encountered after initial treatment of the hydrotest water began. High levels of dissolved iron began to precipitate and plug CETCO’s patented CrudeSorb® media vessels. CETCO’s expertise in solids removal was needed to overcome this initial challenge. After incorporating a process to remove the iron, CETCO treated the hydrotest water, on average, at a rate of 8 barrels per minute. During treatment of the fluid in this tank, CETCO personnel continuously monitored the process and all water discharged to ensure all discharge criteria were met.
Following completion of the first tank in nearly 3 weeks, CETCO’s equipment was moved to a second tank containing approximately 35,000 barrels of hydrotest fluid. CETCO used the same process and treated all of the water in the tank in just one week, completing the tank dewatering by mid-April. The same process was used once again as CETCO treated and discharged another 20,000 barrels of fluid from a third tank located on the tank farm. The third tank was dewatered when the final permit is obtained.
This multi-week project demonstrates the mobility, flexibility, and efficiency of CETCO’s equipment and processes while meeting NPDES permit requirements. All data was obtained using an independent laboratory specified by CETCO’s customer.