Apparatus and method for measuring the flow-rate of different fluids present in multiphase streams

The present invention relates to an apparatus and method for measuring the flow-rate of different fluids present in a plurality of distinct multiphase streams (C), in transit, each through a respective main flow pipe (2). The apparatus (1) comprises a measuring unit (3) for each pipe (2). Each measuring unit (3) comprises a sampling device (4). Each measuring unit (3) comprises first and second measuring means (5) of the differential pressure type situated downstream of the respective sampling device (4). The apparatus (1) comprises a phase separator (8) associated with the measuring unit (3). The apparatus (1) comprises selection means (18) interposed between the measuring unit (3) and the separator (8) for putting the latter in communication with one of the sampling devices (4) envisaged. The apparatus (1) comprises third measuring means (12) associated with the separator (8) for measuring the outgoing flow-rates of the different fluids separated and data processing means suitable for receiving and processing the data revealed by the measuring devices (5, 7, 12).