The physical geometry exhibited by a multiphase flow in a conduit; for example, liquid occupying the bottom of the conduit with the gas phase flowing above, or a liquid phase with bubbles of gas.

The gas volume flow rate, relative to the total liquid volume flow rate (oil and water), all volumes converted to volumes at standard pressure and temperature.

The gas volume flow rate, relative to the oil volumes flow rate, both converted to volumes at standard pressure and temperature.

The gas volume flow rate, relative to the multiphase volume flow rate, at the pressure and temperature prevailing in that section. The GVF is normally expressed as a percentage.

A multiphase flow in which all phases are evenly distributed over the cross-section of a closed conduit, ie the composition is the same at all points.

The total amount of the two or three phases of a multiphase flow flowing through the cross-section of a conduit in unit time. The multiphase flow rate should be specified as multiphase volume flow rate or multiphase mass flow rate.

The flow velocity of a multiphase flow. It may also be defined by the relationship (Multiphase volume flow rate / Pipe cross-section).

A device for measuring the phase area fractions and flow rates of oil, gas and water of a multiphase flow through a cross-section of a conduit. It is necessary to specify whether the multiphase meter measures volume or mass flow rates.

A multiphase flow of oil/gas/water characterised in that the water is distributed as water droplets surrounded by oil. Electrically, the mixture acts as an insulator.

Term used to describe the flow conditions that exist when the phases have different velocities at a cross-section of a conduit. The slip may be quantitatively expressed by the phase velocity difference between the phases.

The flow velocity of one phase of a multiphase flow, assuming that the phase occupies the whole conduit by itself. It may also be defined by the relationship (Phase volume flow rate / Pipe cross-section).

The cross-sectional area locally occupied by the gas phase of a multiphase flow, relative to the cross-sectional area of the conduit at the same local position.

A multiphase flow of oil/gas/water characterised in that the oil is distributed as oil droplets surrounded by water. Electrically, the mixture acts as a conductor.

The water volume flow rate, relative to the total liquid volume flow rate (oil and water), both converted to volumes at standard pressure and temperature. The WC is normally expressed as a percentage.

The water volumes flow rate, relative to the total liquid volume flow rate (oil and water), at the pressure and temperature prevailing in that section.