Frictional Pressure Loss Estimation of Non-Newtonian Fluids in Realistic Annulus With Pipe Rotation

Abstract

Summary The annular frictional performance of non-Newtonian fluids is among the major considerations during development of hydraulic programs for drilling operations. Proper estimation of the frictional pressure losses become more critical when determining hydraulic horsepower requirements and selecting proper mud pump systems to foresee any serious problems that might occur with hydraulics during drilling operations. Because the rheological behaviour of the non-Newtonian fluids is known to be challenging, it becomes even more complicated during pipe rotation, especially in eccentric wellbores. In many cases, significant differences are observed when theoretical calculations and measurements for pressure losses are compared. This study aims to develop correction factors for determining the frictional pressure losses accurately in eccentric horizontal annulus for non-Newtonian fluid, including the effect of pipe rotation. Extensive experimental work has been conducted on METU-PETE Flow Loop for numerous non-Newtonian drilling fluids, including KCl-polymer muds and PAC systems for different flow rates and pipe rotation speeds, and frictional pressure losses are recorded during each test. Rheological characteristics of the drilling fluids are determined using a rotational viscometer. Observations showed that pipe rotation has a significant influence on frictional pressure loss, especially at lower flow rates. Up to a point, as the pipe rotation increases, the frictional pressure losses also increase. As the flow rates are increased, the effect of pipe rotation on frictional pressure losses diminishes. Also, after a certain pipe rotation speed, no additional contribution of pipe rotation on frictional pressure loss is observed. When the developed friction factors are used, there is a good agreement between the calculated and observed frictional pressure losses for any pipe rotation speed.

Hole-cleaning performance comparison of oil-based and water-based drilling fluids

“…Several researchers investigated the drill string rotation effect on the annulus pressure drop by ascribing to the flow regime (laminar or turbulent), formation of Taylor vortices, drill pipe eccentricity and various other parameters (Ahmed and Miska, 2008;Cartalos and Dupuis, 1993;Erge et al, 2015;Erge et al, 2014;McCann et al, 1995;Ozbayoglu and Sorgun, 2010;Saasen, 2013;Sorgun et al, 2011).…”

Simulation of Drilling Pressure Profile in Directional Drilling and User Program Development

“…Ozbayoglu et al [5] proposed the empirical correlation for friction factor in term of both axial and tangential Reynolds number. Friction factor can be classified using total Reynold number, which is the sum of axial and tangential Reynold number, as given below …”

Simple Correlations and Analysis of Cuttings Transport With Newtonian and Non-Newtonian Fluids in Horizontal and Deviated Wells

“…Effective viscosities used in the Reynolds number definitions are expressed as for axial direction [14] (5) 144V'-« and for radial direction [15] (6) K is the consistency index (eq.cp), and n is the Power-Law index. Effective viscosities used in the Reynolds number definitions are expressed as for axial direction [14] (5) 144V'-« and for radial direction [15] (6) K is the consistency index (eq.cp), and n is the Power-Law index.…”