System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy

A system for determining a property of a fluid comprising:

• first and second different diffraction gratings in contact with the fluid;
• at least one interrogation device providing ultrasound incident on the first and second diffraction gratings;
• at least one detector for capturing first and second reflection spectra from the first and second diffraction gratings, respectively;
• and
• a processing device receiving an output of the at least one detector for determining fluid properties based on the first and second reflection spectra.

A method for determining a property of a multiphase fluid comprising:

• interrogating at least one diffraction grating in contact with the multiphase fluid with ultrasound at an angle of incidence by passing the ultrasound through a member comprised of solid material and having the diffraction grating having a grating period formed on a face thereof,
• receiving a response to the interrogating wherein the response includes a reflection spectrum of ultrasound reflected at a predetermined angle relative to the normal of the diffraction grating;
• and
• determining a first value corresponding to a property of the multiphase fluid from the reflection spectrum.

A method for determining a property of a multiphase fluid comprising:

• providing a diffraction grating having a grating period formed on a member comprising solid material;
• providing ultrasound through the member and incident on the diffraction grating at an angle of incidence;
• capturing reflections from the diffraction grating while the diffraction grating is in contact with the fluid and the ultrasound is incident on the diffraction grating;
• and
• determining a first property of the multiphase fluid from a first peak in the spectrum of the captured ultrasound.