Wellhead metering based on bubble and resonance Coriolis effect with known gas liquid ratio
Abstract Coriolis flowmeters are widely used in various industries for their high accuracy in density and mass flow measurement. However, for wellhead produced fluid with low gas content, its metering accuracy will be affected by entrained gas in the fluid. The bubble effect and increase of fluid compressibility have a major impact on the measurement results. In this paper, the influences of gas volume fraction and flow conditions on measurement deviations of Coriolis flowmeter are analyzed by Finite Element Analysis (FEA) method in case of low GVF that is lower than 10% The deviations induced by the bubble effect and resonance effect under the influence of low gas content and flow conditions increase the metering errors of Coriolis flowmeters. The simulation results show that the deviations of fluid density increase negatively with the increase of gas content and the maximum deviation is 37.273% the deviations of mass flow increase at first and then decrease, and the maximum deviation is 9.311% A novel method based on correction model of the measurement deviations induced by bubble and resonance Coriolis effect with known gas liquid ratio is proposed to accurately measure various parameters of wellhead produced fluid. The corrected results show that for the low gas content range (i.e. 0 to 10% GVF) the deviations of gas containing fluid density and mass flow do not exceed 0.3% and 0.5% respectively, which are significantly lower than those before.