A practical approach to the evaluation of subcritical multiphase flow through down-hole safety valves (storm chokes) is presented. This method which is independent of the continuous phase is based on the composition of the flowing mixture and the operating temperature and pressure. In the event of single phase flow, the method can also be applied. With this method, we can easily size subsurface safety valves (SSSV) and chokes as well as determine pressure drops and flow capacities in them. The procedure for the use of this method is outlined and examples illustrate its applicability.
Key words: Multiphase flow, safety valves, down-hole, pressure drops.