Metering multiphase

In new developments, test separators may be substituted by multiphase metering devices which can quantitatively measure volumes of oil, gas and water without the need of separation. This technology is under development. 

The wedge restriction has no critical surface dimensions or sharp edges and tends to retain accuracy despite visible corrosive or erosive wear. It is commonly appHed to high viscosity Hquids, slurries, and hot multiphase mixtures. A similar device is also available using a cone, positioned so that its large diameter is upstream, mounted on the meter centerline. 

With regard to multiphase flow measurement, two of the most commonly used flow meter devices in industry are the Coriolis flow meter and electromagnetic flow meter. The Coriolis flow meter is widely used owing to its high accuracy (Tavoularis, 2005) but it assumes... 

In multiphase flow metering, it is usually required to distinguish hydrocarbon from water. If the liquid phase is "oil continuous," the water fraction can be determined by dielectric constant measurement at microwave frequencies because the dielectric constant of dry hydrocarbon is on the order of 2 to 4 and that of water is 82. Naturally, density measurement can also distinguish water from oil. The next requirement is to distinguish the flow of liquid from the flow of gas in a system where the two will try to separate and travel at different velocities. Cross-correlation by nuclear techniques can measure the density of the stream twice (a short vertical distance apart) and correlate the fluctuations in density with time to determine velocity. Multiphase flow metering is a new and evolving technology,... 

In this paper, we consider the application of two electrical tomographic techniques to the problem of monitoring multiphase flows. Many designs of flow meter are available but, in general, they only operate reliably over a limited range of conditions. If the flow conditions are other than those assumed, inaccurate or misleading indications of flow can be produced. 

There are various applications of multiphase flows in microfluidics. One of the oldest and simplest is using bubble as a flow meter (Fairbrother and Stubbs, 1935). Here, the bubble extends over almost the entire cross-section of the channel, and therefore, the velocity of the bubble is nearly equal to the bubble. The velocity of the bubble can be measured visually and used for the measurement of the total flow rate. Another application is the use of gas... 

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