Patent attributes
Multiphase flow measurement in extreme environments such as subsea or in-well is a difficult task for many reasons including reliability, survivability, and longevity issues; accessibility to the equipment; and complexity of the varying flow field as a function of position and time. Embodiments of the present invention provide techniques and apparatus for performing subsea multiphase flow measurement by combining two technologies. One is based on infrared water-cut measurement technology which is capable of measuring water and oil concentrations in multiphase flow with up to 99.5% gas volume fractions. The second technology is based on in-well fiber-optic flow measurement capable of resolving gas and total liquid flow through the measurements of flow velocity, fluid mixture speed of sound, and absolute pressure and temperature at meter location. This hybrid system represents an approach to subsea multiphase metering that may offer advantages compared to traditional systems for some applications.