Evaluation of Flowloop Uncertainty with Live Hydrocarbon Process Fluids for Multiphase Flowmeters Validation

Abstract

The validation of multiphase flowmeters (MPFMs) in a controlled flowloop using live hydrocarbon fluid is examined with emphasis on the impact of measured and modelled fluid properties uncertainty on the loop reference measurements. A customized process model based on data reconciliation with integrated thermodynamics package is built to evaluate the loop reference flowrates and their uncertainties at the multiphase flowmeter test station conditions. The process model accounts for data redundancy and physical constraints to ensure consistency of the reconciled measured and unmeasured variables used in the validation of multiphase flowmeters. The model is applied to a generic set of test points performed in a high pressure (HP) flowloop. The paper discusses the modeling and operational aspects involved in validating the subsea meter's measured flowrates. It also highlights the sensitivity of different inputs and their uncertainties on MPFM performance evaluation. For the first time, the proposed approach enables operators to achieve the reality of subsea operations inside a highly controlled flowloop environment without resorting to overly simplified assumptions and practices. The approach is further validated by applying it to a high-pressure, high-volume, true multiphase flowloop using actual hydrocarbon fluids.