Infrared Analysis Provides Accurate, On-Site Oil in Produced Water Measurements

As offshore oil wells age, the increase of produced water challenges wastewater treatment systems. In order to ensure oil levels in the water are under the regulatory limit, it is important to do regular testing. Infrared (IR) analysis has been used for offshore oil in water measurements for over 45 years and is an accepted oil content measurement since it is least affected by changes in produced water composition. Fixed -filter IR analyzers, such as the Wilks (USA) InfraCal Analysers, are used to test oil levels in produced water as they are easily operated by non-technical personnel to obtain on-site results in under 15 minutes, eliminating the need to wait for off-site results.  

U.S. EPA methods 418.1 and 413.2 were used extensively on a worldwide basis until the Montreal Protocol called for Freon (the solvent used in the analysis) to be phased out. As IR analysis is typically used as a quick verification that oil and grease levels are below the regulated level, other solvents such as tetrachloroethylene, hexane or S-316 are now widely used on oil drilling platforms even though there is not an associated EPA method for these solvents. There is an ASTM method (D-7066) for infrared oil in water analysis using S-316 as the extracting solvent.

Wilks InfraCal Analysers give results in less than 15 minutes and have a reputation for the rugged durability required in the offshore environment. The sampling requires a few simple steps that can be performed by non-technical personnel. The water is mixed with the extraction solvent, shaken, and then presented to the InfraCal Analyser for measurement.

If sub-ppm measurements, password protected calibrations and instrument settings, data storage or multiple calibrations are required, the new InfraCal 2 offers increased sensitivity as well as a touch screen display for more user options.