Water detection and 3-phase fraction measurement systems

An optical water detector for monitoring a hydrocarbon well, comprising:

• a source for emitting into a flow stream light that includes a first wavelength band associated with absorption by water;
• a detector configured to detect attenuation of the first wavelength band upon the light passing through at least a portion of the flow stream;
• and
• an output indicative of a concentration of water as determined based on the attenuation of the first wavelength band, wherein the output is configured to adjust an amount of hydrate inhibitor based on the concentration of water.

A method of detecting water within a flow stream of a hydrocarbon well, comprising:

• emitting into the flow stream light including first and second wavelength bands associated with absorption by water, wherein the second wavelength band is less absorbed by water than the first wavelength band;
• detecting attenuation of the first wavelength band upon the light passing through at least a portion of the flow stream;
• determining a concentration of water based on the attenuation of the first wavelength band;
• and
• detecting attenuation of the second wavelength band instead of or in addition to the first wavelength band when the concentration of water is higher than a certain level.