Development of a metering system for total mass flow and compositional measurements of multiphase/multicomponent flows such as oil/water/air mixtures

Abstract

The development of a technique for continuous measurement of the total mass flow and composition of oil/salt water/gas mixtures in pipelines has a particularly important bearing on the technical and economic aspects of future production projects, including the explotation of marginal offshore oilfields, and the piping of such mixed fluids to central production platforms or onshore. A test rig, which can be operated with oil, water and air either separately or in combination, was used to prove a potentially feasible combination of instruments consisting of a venturi tube, a capacitor and a single-beam gamma densitometer. Testing showed that the metering system functions properly and supplies easily evaluable signals only if the various components are distributed virtually homogeneously throughout the flow with oil or air forming a continuous phase. Further work is necessary to develop a sufficiently sophisticated version able to cope with actual operating conditions.