Many new oil wells generally have minimal water and low gas production. However as time progresses the wells often start to produce water. Pressure reduction and gas breakout in the well over time also causes more gas flows at the wellhead and in the multiphase meter.
To continue and enhance production, many fields need Enhanced Oil Recovery (EOR) methods. Common EOR methods include gas lift, water injection and submersible pumping. All of these methods impact the well-stream, and contribute to variations and changes of the Gas Volume Fraction (GVF) and the Watercut over time.
In many oil and gas production facilities it is not unusual for a single phase to dominate, depending upon the nature of the field, and the techniques used to develop it. In the case where one phase predominates, it means that the flows of the other phases are small and relatively difficult to measure. In wetgas conditions the gas phase is dominant, and the liquids consist of relatively small quantities. If at the same time, the watercut in the small quantity is high then the oil is even more difficult to measure at high precision. Multiphase Metering covers in principle all possible combinations of flow rates of oil, water and gas. While future production rates and other process parameters are easy to predict for some applications, they can be quite uncertain in other applications. Also, the flow rates and the well characteristics can change dramatically over time. In some cases the well may start as a typical oil producer, and then turn into a typical gas well later on.