NON-NEWTONIAN RHEOLOGY MEASUREMENT BY USING DIFFERENT TYPE OF RHEOLOGY INSTRUMENTS

Abstract

A non-Newtonian fluid is a fluid whose flow properties cannot be defined by a single constant named viscosity. Many drilling fluids, polymer solutions and molten polymers are non-Newtonian Fluids in a Newtonian fluid, the relation between the shear stress and the shear rate is linear and the constant of proportionality being the coefficient of viscosity.

Analysis of fluid flow operations requires material-specific information such as the relation between density, pressure, and temperature which is collectively known as constitutive relations. Rheology is  the science explained the suitable constitutive equations for description of the behavior of Non-Newtonian fluids.

Although the non-Newtonian behavior of many fluids has been known for a long time, the science of Rheology is, in many concepts, still in its beginning, and new phenomena are constantly being discovered and new theories proposed.

In this work we apply many of non-Newtonian models (Bingham, Power Law, Herschel – Bulkily model and Ellis model) to measure the Non-Newtonian properties such as consistency index (k), Power law parameter (n), plastic viscosity (µp), yield stress (?o) and other properties. Two fluid samples of Non-Newtonian fluids (fracturing fluid and drilling fluid) were used. Comparing between the results obtained from different models and the evaluation which model are suitable for each of the fluid sample used in this experimental work are also done. The results showed that Power law model is good to analyze the fracturing fluid data and getting good results. Also, the Bingham model was gave acceptable results and easier ways to get the important results for analyzing drilling fluid data.