System and method to measure salinity of multi-phase fluids

A system for determining salinity of a multi-phase fluid flowing in a conduit, the system comprising:

• a sensing device placed on or about the conduit and configured to emit electromagnetic waves of one or more frequencies;
• and
• a controller configured to
• excite the sensing device to emit electromagnetic waves of the one or more frequencies towards the multi-phase fluid,
• receive electromagnetic waves corresponding to the electromagnetic waves of the one or more frequencies emitted by the sensing device into the multi-phase fluid,
• determine an intermediate parameter from the received electromagnetic waves, wherein the intermediate parameter is used to determine an admittance value,
• obtain estimated values of at least one of a plurality of parameters based on the admittance value, wherein estimated values of the plurality of parameters comprise at least one of an estimated value of conductance, an estimated value of susceptance, an estimated value of differential conductance, an estimated value of differential susceptance, an estimated value of a real part of complex permittivity, and an estimated value of an imaginary part of complex permittivity,
• compute a first ratio between the estimated value of the imaginary part of complex permittivity and the estimated value of the real part of complex permittivity,
• compute a value of the real part of complex permittivity and a value of the imaginary part of complex permittivity,
• determine a second ratio between the computed value of the imaginary part of complex permittivity and the computed value of the real part of complex permittivity,
• compute a difference between the first ratio and the second ratio by comparing the first ratio to the second ratio, and
• determine the salinity of the multi-phase fluid based, at least in part, on the difference between the first ratio and the second ratio, wherein
• the sensing device includes an antenna and a radio frequency (RF) connector that is operatively coupled to the antenna;
• the antenna is an open-ended coaxial probe configured to receive control signals from the RF connector and to emit the electromagnetic waves into the multi-phase fluid in accordance with the received control signals;
• and
• a surface of the antenna is partially covered by a metallic holder such that the multi-phase fluid only directly contacts the antenna via a portion of the surface of the antenna uncovered by the metallic holder.