METHOD FOR DETERMINING FLOW CHARACTERISTICS OF MULTIPHASE FLOWS

摘要

The present invention relates to a method for determining at least one dynamic flow characteristic of a multiphase flow circulating in a pipe, said flow being composed of at least a lighter dispersed-phase and a heavier continuous-phase. A tracer is discharged (or activated) into the flow at a chosen first location in the pipe by mixing (or activating) at least a portion of the tracer with the continuous-phase therein. The tracer concentration at at least a chosen second location in the pipe is measured with a detector as a function of time t, so as to obtain at least one signal S(t). Then a relationship is fitted to the signal S(t) so as to derive the values of the velocity U of the continuous phase and/or of a dispersion coefficient k. The slip velocity vs of the dispersed phase relative to the velocity of the continuous phase is also advantageously determined. From the values of velocities U and vs and from the volume fraction yl of the continuous phase in the pipe (obtained by an ancillary measurement), the volumetric flow rates of the continuous and dispsersed phases are determined.