An improved solution for estimating the flow rate of a fluid in the wells of a hydrocarbon production installation, during production. A hydrocarbon production installation can include at least two production wells, each production well including at least one device adapted for providing an estimate of the flow rate of a fluid in the well based on respective data, the wells being connected to a test separator adapted for providing an estimate of the cumulative flow rate of the fluid for all of the wells based on respective data. Further, during production, a data reconciliation and validation process can involve the data relative to the devices and the test separator.