Methods and systems are described that provide for measuring flow properties of multiphase mixtures within a pipe carrying gas-liquid hydrocarbons and water produced from oil-gas wells. The methods and systems may provide for a combination of a clamp-on ultrasonic gas flow meter to measure flow characteristics of a gas phase in a pipeline and a pulsed ultrasonic Doppler sensor(s) and/or an RF/microwave electromagnetic sensor(s) to measure flow characteristics of a liquid phase. The combination of sensors may provide for multiphase flow measurements under certain flow conditions, such as when the gas-liquid is flowing in a substantially horizontal pipeline, when the flow is stratified or is caused to be stratified and/or the like.