There is a perception in the industry that the accuracy of low energy gamma ray multiphase meters suffers in wet gas or high GVF environments. This is generally attributed to the low density of the process flow having a much more reduced effect on the gamma ray beam and thus a reduced overall accuracy of measurement. These perceptions can have a dramatic impact on the cost of installations for monitoring Wet Gas flow where alternatives to multiphase meters can be tens of millions of dollars more expensive.
This paper describes a successful performance test of a 88-mm-ID venturi, low energy gamma ray, multiphase meter at the CEESI wet gas facility in Colorado, USA on 31 October 2012. The test was performed at CEESI, an independent third party test facility which is well known in the industry for its high quality & accurate wet gas flow loop.
The performance test was witnessed by participants from:
The test envelope for the flow test was in the wet gas region with Gas Volume Fractions (GVF) range from around 97% to over 99.5% and a wide range of Water Liquid Ratios (WLR). The number of flow periods in the test matrix was limited due to the requirement to complete the flow test in a single day. Participants were also given the opportunity to propose flow rates for the flow periods run during the day of testing.