Solutions for monitoring viscosity at reference temperature in the oil and gas industry

Viscosity is the physical property, that describes how a fluid is flowing under a given constraint (strength), is a function of temperature. 

Monitoring viscosity at the process temperature is the solution that requires little investment and is easy to implement either directly in the main line or via a by-pass loop. When the process temperature is stable, or its influence on viscosity well known, this is the solution. 

When process temperature changes in a too wide range and when its impact on viscosity is not manageable by team in charge of controlling the process, the need for a stable level of viscosity at a constant reference temperature arises. Sofraser the inventor of the vibrating viscometer held at resonance frequency, patented in 1981, is very experienced at offering a range of solutions that meet this requirement. 

The entry-level solution is named TCV, which stands for ‘Temperature Compensated Viscosity’. Viscosity at a constant reference temperature is calculated thanks to the viscosity measured at the process temperature and a mathematical model that accounts for the influence of temperature. When this influence is known the parameter(s) for the mathematical model can be determined and set in the 9710 HMI processor that takes the calculation into consideration. The 9710 TCV feature is available with the equation described in the ASTM D-314 standard that is ideal for petroleum products among many others. 

When the behaviour of the product changes and influence of temperature on viscosity is no longer constant, the Sofraser’s Thermoset analysers offer the solution. These analysers are designed to measure the viscosity at the required reference temperature. Thermoset CF and LT both operate between the sample temperature and the reference temperature thanks to the cyclic mode developed by Sofraser in the 80s. Thermoset KV is the only process analyser able to deliver directly the kinematic viscosity without the need for an additional density meter. 

Used in the oil and gas and chemical industries, the Thermoset analysers are rugged and easy to maintain solutions that have proven their efficiency even in high viscosity streams that are rarely handled by other viscometers using alternative measuring principles and with the same ROI. Indeed, Thermoset analysers can be installed with minimal conditioning of the sample and require almost no maintenance.