Multiphase Meters, Ready for Field Applications: Results From Full Scale Qualification Testing
Authors: Økland O. , Berentsen H. , Bruun-Olsen J. 
Published: October 2008

ABSTRACT
Experience gained from the testing of 3 different multiphase meters at the Gullfaks B platform (GFB) shows that these meters are very efficient for well testing. The time needed to perform one well test is reduced to the well change-over interval and a short test interval. For one of the meters the accuracy has been proven to be within +/- 5 YO for flowrates in oil-continuous flow at Gullfaks flow condition. Testing performed late 1994 has shown that themultiphase meters from Framo Engineering and Multi-Fluid Int. are commercially attractive. The three Norwegian oil companies Statoil, Saga and Norsk Hydro have now started a programme for testing and qualification of four different meters for specific field applications in a high pressure testing facility. Furthermore one of these meters will be chosen for building of a subsea meter which will be ready for installation by the end of 1996.

INTRODUCTION
Some years ago the main discussion wrt. multiphase metering focused on the possibility to succeed in developing a reliable generally applicable multiphase meter. Today several first generation meters are commercially available. For the last two years many oil companies have gained experience with different meters from field tests. The mainissue now is to investigate the performance of thevarious meters with respect to accuracy and reliability, and to find "the application envelope" with respect to flowrates, fractions and flow regimes relative to planned field developments. The oil industry is about to apply multiphase meters both topside on platforms and subsea on satellite fields on a permanent basis. However, no subsea meters are presently commercially available
Applications of multiphase meter can be devided into two groups:WELL TESTING - Testing of a well's performance without using the test separator. The information is used for reservoir management and production optimisation.PRODUCTION ALLOCATION - This will be a "fiscal" metering where the multiphase meter measurements are used as a basis for calculatingtaxation or to apportion production between production licenses.

PREVIOUS WORK
Previous tests of multiphase meters at Statoil's Gullfaks B platform (Fluenta's MPFM 1900 and Multi-Fluid's (MFI) LP-Meter), took place in December 1992 and in March 1993. The results from these tests have been published earlier [1,2,3].
To summarize the experience with these two electromagnetic meters, they both measure the composition of the oil-continuous wells at GFB with a satisfactory accuracy. The MFI-meter can also be used to measure flow rates. From a users viewpoint these tests indicate that the time is approaching when qualified multiphase meters can be implemented.
In July 1993 new tests of the same two meters took place, confirming the earlier results and giving only marginal new information wrt. overall accuracy and performance. In March 1994, a multiphase meterfrom Framo Engineering was installed and tests of this meter were performed twice in March and November. In the end of November a new meter from MFI, with no limitation wrt. water cut, was successfully installed (Full-Range meter). The results presented below are divided into two parts.