Equipping North Sea Oilrigs to Analyze Oil in Water

North Sea fisheries and petroleum reserves are vital to the well-being of countries in the United Kingdom, northern Europe and Scandinavia. To ensure a healthy coexistence with local marine life, petroleum companies must carefully manage any waste byproducts created during the oil extraction process.

By volume, a substance called "produced water" is the primary waste stream from seafloor oilrigs. It typically includes water present in the oil formation and any water or chemicals injected during extraction. Various environmental regulations put limits on the oil and chemical content of produced water. Other regulations affect the associated analysis procedures: in Norway, for example, the government prohibits the use of Freon as a solvent for oil-in-water analysis.

Norsk Hydro is Norway's second largest corporation and a major North Sea petroleum producer. To help ensure compliance, it decided to equip its oilrigs with an analysis solution that was (a) compatible with Norwegian standards, (b) able to discriminate various types of oil in water and (c) small enough for the cramped confines of an offshore oilrig. The company turned to Matriks AS, an Agilent authorized reseller in Oslo, Norway. Matriks not only created a system that met all three criteria, it also provided operator training, system installation and analysis implementation.

Creating a compact solution

Working with West Lab Services of Stavanger, Norway, Matriks created an analysis procedure—adapted from Norwegian Standard EN ISO 9377-2—that uses n-pentane rather than Freon. This new method was designed to run on a compact Agilent 6850 gas chromatograph (GC) equipped with a standard flame ionization detector and an HP-1/SIMDIS column (15 m x 530 m x 0.15 m; part number 19095Z-221).

Because the procedure requires very low discrimination between various oil components in water, injections must be performed at temperatures below 0° C. To achieve this, a liquid-cooled programmable temperature vaporization (PTV) inlet was installed in each GC. This modification also saved space by eliminating the gas containers used with Agilent's standard PTV inlet.

To separate the organic phase from the water sample, a microseparator was also developed. This increased system efficiency and saved additional space compared to typical techniques that use separation funnels.

Ensuring proper performance

Before delivery to the customer, the systems were calibrated and verified by Matriks at its Oslo lab. After internal approval the systems were repacked and sent offshore for final installation. To ensure proper performance on the oilrigs, the installation process included recalibration of each instrument, analysis of control samples, and comparison of results to in-lab measurements.

This is just one example of the systems and services provided by Agilent solution partners around the world. The application expertise—and local presence—of companies like Matriks contributes to the success of Agilent customers in many industries.

For more information

To learn more about solutions for similar applications, please see the Environmental and Hydrocarbon Processing pages. For additional information about these and other Agilent chemical analysis products and resources, please visit the Life Sciences/Chemical Analysis main page.