METHOD OF MEASUREMENT OF PARAMETRES OF VISCOELASTIC FLUID MEDIUMS AND DEVICE FOR ITS REALISATION Russian patent published in 2011 - IPC G01N11/16 

FIELD: oil and gas production.

SUBSTANCE: method consists in excitation of vibrations of hollow resonance device by means of supply of continuous signal of alternate frequency to two emitting converters located on external surface of resonance device. Also, one receiving converter on external surface of the resonance device records these vibrations. There is plotted an amplitude-frequency characteristic and there is determined value of frequency of working resonance ω_r. Further, a cavity of the resonance device is filled with analysed medium and vibrations are excited in the filled resonance device by supplying a continuous signal of alternate frequency to emitting converters; vibrations are recorded. There are excited torsion vibrations; values of amplitude-frequency characteristic are determined by the first mode of vibrations. A tank with axial symmetry installed in a thermo-stabilised chamber is used as the resonance device. Dimensions and material of the resonance device are chosen to minimise influence of vibrations modes different from working resonance. There are determined attenuation coefficient a of the resonance device, hollow and filled with analysed medium, also shear of value of resonance frequency Δω_r and change of attenuation Δα relative to a hollow resonance device. Actual part of shear modulus µ and dynamic viscosity η are calculated by formulas: , where ω_r is value of resonance frequency for a tank not filled with liquid medium, Δω_r is shear of resonance frequency, Δα is change of attenuation, ρ is density, R₁ and R₂ are internal and external radii of a tank, lower indices f and s relate correspondingly to liquid medium and a tank.

EFFECT: upgraded accuracy of measurement of viscoelastic liquid medium parametres in wide range of temperatures at low expenditures.

16 cl, 9 dwg