Provided is a tool-body that arranges ultrasonic and electrical capacitance sensors at close distances to the casing wall of the wellbore such that properties of thickness, flow velocity, acoustic impedance and the dielectric constant of the liquid layer are measured at a number of circumferential locations inside the casing of the wellbore. These measured values may then be combined to derive the average flow rate of the layer and also used to identify whether the liquid is water or condensate/oil, or a mixture of the two with a certain water-in-liquid ratio. Combined with a gas flow rate and a liquid droplets concentration measurement, the total liquid flow rate and liquid type can be derived.