Separator and a plurality of multiphase meter systems and methods

A separator and a plurality of multiphase meter systems and methods are disclosed. A well test system for testing fluids produced from one or more petroleum wells has the separator and the plurality of multiphase flow meter systems. Each of the multiphase flow meter systems has the capability, over at least a portion of its operating envelope, of separately measuring flow rates of oil, water, and gas. The well test system has a fluidic system. The fluidic system includes gas leg conduits coupling the separator to the multiphase flow metering systems, liquid leg conduits coupling the separator to the multiphase flow metering systems, and bypass conduits for directing multiphase fluid to the multiphase flow metering systems while bypassing the separator. Valves are configured to selectively route fluid flow though the fluidic system to selectively bypass the separator when the multiphase flow metering systems can be used to provide separate flow rates of oil, water, and gas in the unseparated multiphase fluids from the well.