44th Workshop on Geothermal Reservoir Engineering, Stanford University, California, United States Of America, 11 - 13 February 2019, vol.213, pp.1-7
Accurate estimation of annular friction pressure loss is necessary to perform drilling and well completion operations without lost
circulation, pipe sticking or more serious well control problems. Determination of friction pressure loss for Newtonian and non-Newtonian
fluids has been investigated in several experimental and theoretical works by considering the effects of eccentricity, pipe rotation or pipe
geometry. However, there is a gap in the studies about the temperature effect that is important especially in geothermal wells.
This study experimentally investigated the effect of temperature on friction pressure loss through vertical concentric annulus by using
water and the polymer based drilling fluid including Polyanionic Cellulose and Xanthan Gum. Experiments were conducted in flow loop
having 21-ft smooth and concentric annular test section (2.91 in ID casing x 1.85 in OD pipe).
The effect of temperature on rheological model parameters, apparent viscosity, Reynolds number was examined. It was found that
consistency index and yield point were more sensitive to change in temperature than flow behavior index. Also, apparent viscosity
decreased exponentially with increasing temperature and this decrease was more obvious in low shear rate values. Then, according to
Reynolds number – temperature plot, earlier regime transition was observed with increasing temperature.
As a result, increasing temperature caused the decrease in friction pressure loss, and temperature effect should be considered in future
experimental and theoretical studies in order to estimate friction pressure loss in annuli precisely.