The paper describes a novel positive displacement flowmeter developed to measure the mass and volumetric flowrates of multiphase crude oil fluids in flowlines. After an introductory review of the technical and economic incentives for the development - particularly offshore and subsea, the paper goes on to explain the hydrodynamic problems that hitherto have inhibited the use of conventional metering techniques for multiphase flow measurement.
The paper then describes how these problems have been resolved by a novel combination of simple, well tried principles. The design concepts of the new meter are outlined, together with a brief review of its development from conception to the completion of endurance and calibration tests on two field trial meters. Special features of the positive displacement mechanism design, which enable the meter to withstand rigorous multiphase flow regimes, are explained. Field trial results confirming the meter's capability to resist such conditions are reported, as are the results of independent checks of its measurement accuracy, assessed over a wide range of flow regimes and void fractions. Comparison is made between the performance of the meter and that of a test separator system.