Mass Flow Rate Measurement of Oil-Water Two-Phase Flow by a Long-Waist Cone Meter

A long-waist cone meter is proposed for horizontal oil-water two-phase flow rate measurement. A constricting differential pressure Δp and an overall differential pressure δp were tapped for flow rate measurement. Δp is related to flow rate through Bernoulli´s equation. A correlation for predicting the mass flow rate by using the overall differential pressure δp is presented through physical analysis. Correlations of Δp and δp are then extended to predict the mass flow rate of two-phase flow based on the separated flow model. A dual differential pressure model is then proposed by combining the two correlations of Δp_tp and δp_tp. The flow regimes in the experiments include water continuous and oil continuous. Prediction on overall mass flow rate is improved by using the dual differential pressure model at an associated error of 2.7% and 4.1%, respectively, for water-continuous flow and oil-continuous flow. This paper indicates that the overall mass flow rate of oil-water two-phase flow can be determined at an accuracy within ±5% with a long-waist cone meter and the dual differential pressure models without the aid of a secondary instrument for the phase fraction measurement, and the results are less affected by phase inversion.