Oil-in-water monitoring and analysis is a subject of interest to both regulatory authorities and industry. Accurate and reliable measurement of oil- in-water plays an important role in the minimisation of oil pollution into the environment.

The discharge of produced water into the North Sea has been regulated predominately based on the measurement of oil in the discharged water; currently a monthly average of 30mg/l or less is permitted for discharge. A new reference method has been introduced to facilitate this. However, the current lack of associated precision data and reference standards make implementation diffcult and problematic.

The new reference method, OSPAR GC-FID (Gas Chromatography and Flame Ionisation Detection) was recommended by OSPAR in 2003 and has been widely implemented across the North Sea since January 2007. At present, there is no precision data associated with this method. Consequently little is known about the repeatability or reproducibility of the method and it is diffcult to estimate the uncertainties associated with reported results. In addition, laboratories are unable to easily assess how well the method has been established in-house.

A DIUS-sponsored Joint Industry Project (JIP) is currently underway in collaboration with LGC to address this issue. The project will produce data to assess new oil-in-water analysis method measurements. It also aims to develop a new reference standard of oil-in-water, and establish the precision data for the OSPAR GC-FID method. Project fndings and results will be disseminated to OSPAR and throughout industry.

It is anticipated that this project will beneft industry in oil-in-water analysis method validation, method comparison, calibration, and the running of profciency testing schemes.

This government-sponsored JIP is supported by two offshore operators and eight testing laboratories involved in the oil and gas industry. The JIP will disseminate results to industry. An update on project progress will be given at TUV NEL’s Oil-in-Water Monitoring Workshop event in September 2009.

This article originally appeared in "Flow Tidings Spring 2009" (You must be registered and logged in to view this document)