Flow measurement

Abstract

A method of determining an estimated flow rate for at least one phase of a multi-phase fluid flowing from a subsea well; a subsea well; and a system for determining an estimated flow rate for at least one phase of a multi-phase fluid flowing from a subsea well are disclosed. The method of determining an estimated flow rate for at least one phase of a multi-phase fluid flowing from a subsea well comprises determining a mass or volumetric flow rate of a fluid in a completion or production tree of a subsea well; determining a Water Liquid Ratio (WLR) of said a fluid via a water sampling device; determining an upstream fluid pressure and an upstream fluid temperature of said a fluid at a location upstream of a production choke valve in the subsea production tree via at least one pressure sensor element and at least one temperature sensor element of the subsea production tree; determining a downstream fluid pressure and a downstream fluid temperature of a fluid at a location downstream of the production choke valve via at least one pressure sensor element and at least one temperature sensor element of the subsea production tree; determining a downhole fluid pressure and a downhole fluid temperature of said a fluid via at least one pressure sensor element and at least one temperature sensor element located downhole in the completion; and providing each of the determined mass or volumetric flow rate, water liquid ratio, upstream fluid pressure, upstream fluid temperature, downstream fluid pressure, downstream fluid temperature, downhole fluid pressure and downhole fluid temperature as respective inputs for a statistical estimator unit and, via the statistical estimator unit, determining an estimated flow rate for each of at least one phase of fluid flowing downstream of the choke valve.