A robust vibrating wire viscometer for reservoir fluids: results for toluene and n-decane

A vibrating wire viscometer has been constructed as an integral part of the floating piston within a reservoir fluid transportation and storage vessel. The vibrating wire is 0.1 mm in diameter, 30 mm long and is made of tungsten. The radius of the wire was obtained from calibration measurements in toluene at a temperature of 323.15 K and pressure of 0.1 MPa, while the internal damping was obtained from a measurement in vacuum. The sensor was then used to measure the viscosity of toluene at temperatures of 323.15 and 373.15 K at pressure up to about 90 MPa. The results of these measurements differed by less than 2% from those reported in the literature. The instrument was also used to determine the viscosity of n-decane at temperatures of 323.15 and 423.15 K and pressure up to about 90 MPa. At the lower temperature, the results obtained were also in good agreement with literature data.