Wetgas meter
Wetgas is a form of multiphase flow where the gas is the dominant constituent.

The wetgas meter incorporates three different methods for measurement of the fractions and the flow rates of the wetgas, which can be used to determine PVT properties. This is an in-line continuous measurement, which is performed while the well is flowing based on recalculation of the following measurement modes:

1. three-phase mode

2. three-phase mode without droplet count

3. two-phase made with GOR input

For practical purposes, wetgas metering is defined as a flow where the gas has enough momentum to carry the liquid in a relatively stable flowing regime, with no slugging. Wetgas fields typically have GVF’s in the range from 95 - 99.99 % or Lochart Martinelli parameter below 0.3. The liquid fraction for these gas conditions can obviously be very small, and splitting the tiny amounts of liquids flowing with the gas into water and condensate, and measuring these at acceptable accuracies, is very challenging. For such field applications, there is often a need being able to monitor both fresh and formation (i.e. salt) water break-through from a reservoir and production optimization point of view. This can be for control of chemical injections to avoid pipeline corrosion, hydrate formation, waxing, etc.

For more information:
http://www.fmctechnologies.com/en/Multiphase-meters/Products/Wetgas-meter.aspx