Analysis of the Effect of Eccentricity on Flow Characteristics of Annular Flow of Non-Newtonian Fluids Using Finite Element Method

Abstract

Abstract One of the most difficult tasks in petrolum industry is to characterize the behavior of non-Newtonian fluids flowing through eccentric annulus. Many empirical and semi-empirical approaches have been introduced which attempt to solve this problem. Also, there are few analytical methods proposed, however, the performance of them were not promising. This study aims to approach the problem using finite element method (FEM), which became popular lately due to the developments of the computer technology. Defining a typical wellbore size commonly encountered in CT applications, three different non-Newtonian fluids were tested at three different eccentricities. Different FE mesh types were used to increase the accuracy of the results. The FEM results were compared with different conventional methods as well as experimental results which were available in the literature. The results showed that, as the eccentricity is increased, FEM can estimate the frictional pressure losses more accurately than conventinal methods. It is observed that, as the eccentricity is increased, frictional pressure loss is decreased, if all the other parameters are kept constant. Moreover, the velocity profile across the wellbore can easily be determined, which is very important to identify the hole cleaning performance of a fluid.