Accurate measurement of the output of wet gas fields is an important means of reducing the financial risks that Exploration & Production (E&P) companies face in sales gas allocation. Ultrasonic flow meter technology is proven for dry gas metering and E&P companies now hope to apply it to wet gas. DNV GL has therefore initiated a Joint Industry Project (JIP) to build a solid foundation to facilitate the wide acceptance of this technology for use in wet gas sales allocation. Seven industry partners have committed to the JIP, but it is open for more partners.
Currently, multiphase flow meters and wet gas flow meters are used for both topside and subsea measurements. They enable operators to improve reservoir modelling and management, optimise production and manage flow assurance. The output of wet gas flow meters is also used to determine sales allocation between E&P companies and the royalties payable to the host government.
“Ultrasonic flow meters are an alternative to accepted technologies and can be used both in-line and clamp-on. The technology has been used successfully for dry gas metering over the last decades and the first results under wet gas conditions are promising. However, there is no systematic approach to its use for wet gas. Biases will occur under wet gas circumstances and therefore an accepted correction algorithm is required. This correction algorithm is seen as an important step towards qualifying ultrasonic flow meters for wet gas metering. The JIP will therefore provide testing guidelines and correction algorithms as a foundation for using ultrasonic flow meters for wet gas,” says Dennis van Putten, expert multiphase flow metering, DNV GL Oil & Gas.
To achieve this correction algorithm, a test programme will be performed under conditions close to real field situations (natural gas/water/oil mixtures). These conditions can be created in DNV GL’s Multiphase Flow Facility (Groningen, The Netherlands). “We designed and constructed this new facility for these types of tests in 2013, and its value has already been recognised by the industry,” Dennis van Putten explains.
“Wet gas measurement is a complicated subject that requires strong attention as the risk of mismeasurement of produced volumes is large. The value for E&P companies in joining this JIP is in finding solutions that can mitigate the large financial risks present in sales gas allocation systems. We have already seen a lot of industry interest in this project,” says Henk Riezebos, senior principal specialist metering, DNV GL Oil & Gas.
“Ultrasonic flow meter manufacturers participating in the JIP will gain valuable insight into the performance of their own technology under wet gas conditions and the JIP will provide them with a route to broad industrial acceptance and corresponding access to the market,” Riezebos continues.
DNV GL is looking for E&P companies and ultrasonic flow meter manufacturers that are interested in participating in the JIP. Industry partners are welcome to join the kick-off meeting on 5 May 2014 in Groningen, The Netherlands.