Multiphase flow metering has become one of the main well testing and reservoir production monitoring for many oil operators. The technological advances in instrumentation and flow modelling has been lately able to address the challenging application in measuring the flow rates of high gas-oil-ratio (GOR) and high gas volume fraction (GVF) with an acceptable accuracy and reliability.
The objective of this paper is to discuss and evaluate the results of a pre-qualification test of three Multiphase Flow Meter (MPFM) technologies conducted in various third party flow loop test facilities mimicking high GOR field conditions. It will also clearly set the procedures and methodologies used to verify the field performance and viability to install those MPFM technologies in a high GOR environment.
Oil fields producing under high GOR flow conditions (more than 90% GVF) pose a technical challenge for in-line MPFM to provide accurate and reliable flow rate measurements. The testing of those technologies in the filed in such harsh environment requires a great deal of planning and careful design and monitoring of the reference measurement that imposes a major time and cost impacts. For this reason, a pre-qualification test of potential MPFM technologies for high GOR environment was conducted in a third party flow loop facility utilizing live hydrocarbons under simulated field operational conditions. These technologies are based on Venturi in association with additional measuring principles to cope with the high GOR conditions including nuclear fractioning, tomography, gamma-ray densitometer and multi-dimensional and multi- frequency electric permittivity measurement system.
This pre-qualification flow loop test was designed to ensure that clear conclusions are reached and that a purely objective evaluation of the results can be performed. Evaluating these MPFM technologies in well controlled and contained flow low loop has enabled a solid assessment of the metrological performance under high GOR. A coherence GVF mapping of each MPFM technology was formulated to help in the assessment in selecting the appropriate technology for the field application.