Session: 11-02-01 Well Drilling Fluids and Hydraulics-1

Submission Number: 181498

Modelling the Frictional Pressure Drop of Herschel-Bulkley Fluid Flow in an Annulus With Inner Cylinder Rotation and Eccentricity 

The flow of a non-Newtonian fluid in an annulus with inner cylinder rotation and eccentricity is characterized by sophisticated flow patterns that may require vast computational power or time to be resolved. The problem complexity increases for higher flow rates and rotational frequencies, having to consider the effects of axial and tangential turbulent motion, in addition to the shear-thinning and yield stress properties of many non-Newtonian fluids. Furthermore, annulus eccentricity causes non-uniform axial flow while also disturbing any assumed axisymmetric rotational flow in a concentric annulus. 

Due to the added flow complexity, drilling hydraulics models are often based on purely axial flow, while the effects of rotation and eccentricity on the frictional pressure drop can be estimated and applied via empirical correlations. Correlations have been developed for inner cylinder rotation and eccentricity separately. However, limited work has been done on correlations that capture the combined effect.

In this paper we combine experimental flow loop data, numerical simulation, and analytical calculation in an improved approach towards empirical modelling of the frictional annular pressure drop in Herschel-Bulkley type fluids with varying inner cylinder rotation and eccentricity. The need for a correlation that captures the combined effect of rotation and eccentricity has been demonstrated through numerical simulation, showing the dependence between the effects. The presented modelling is based on dimensionless quantities for generalizability and scalability across different annular flow systems.

Presenting Author: Annika Torsvik SINTEF

Presenting Author Biography: Annika Torsvik is a researcher within Applied Geoscience at SINTEF AS in Bergen, Norway. She holds a M.Sc. in Applied Physics and Mathematics at the Norwegian University of Science and Technology (NTNU). Her current research interests are drilling fluid hydraulics, fluid rheology, and digital modelling of physical systems including numerical simulation and machine learning.

Authors:

Annika Torsvik SINTEF
Bjørnar Lund SINTEF
Omar Emmanuel Godinez Brizuela SINTEF
Roar Nybø SINTEF
Arild Saasen University of Stavanger