Simulation of Pressure Buildup in a Multiphase Wellbore/Reservoir System

A pressure-buildup test is simulated in a system consisting of a wellbore and a reservoir and containing multiphase fluid. Wellbore flow is governed by conservation of matter and momentum, and reservoir flow by conservation of matter and Darcy's law. Finite-difference versions of the flow equations are solved on a discretized system. A single-phase example illustrates wellbore storage and wellbore fluid inertia shortly after shut-in. Two-phase examples illustrate phase redistribution, and one shows a ''hump'' caused by phases segregating. Buildup and other data from a field case are also matched.