2-PHASE PRESSURE-DROP PREDICTIONS ACROSS GRAVEL PACKS

In applying nodal analysis to optimize the performance of a single wel l, it is critical that we are able to estimate the pressure drop acros s each of the components of a complete well system, from the outer bou ndary of the reservoir to the sandface, from the tubing string to the separator including any restrictions, safety valves, and surface choke . Relationships for rate vs. pressure drop under single- and two-phase flow conditions are available for most of the components with the exc eption of perforations and gravel pack. This paper presents the proced ure for calculating the pressure drop across perforations and gravel p ack under two-phase flow conditions. Results are presented indicating the difference between single- and two-phase flow calculations. It is shown that if the two-phase flow is not properly accounted for, we can significantly underestimate the pressure drop across the gravel pack and perforations.