Pressure Drop in Tool Joints for the Flow of Water-Based Muds in Oil Well Drilling (original) (raw)

The characteristics of the fluid flows in tool joints were studied experimentally and theoretically in a laboratory scale. The goal of this study was to evaluate the pressure drop in accessories such as tool joints, placed along the drilling columns. The experimental fluid flow loop consisted of a 25-hp positive displacement pump, a 500-liter tank, a 3-HP mixer and a series of circular and annular pipes where the tool joints were installed. Based on the Reynolds number, the fluid flow loop was set to have dynamic similarity with respect to the real hydraulics of oil well fields. CFD simulations were implemented to aid in the design of the fluid flow loop. Pressure drop and fluid flow rate data were experimentally determined in a set of tool joints using water-based muds with non-Newtonian behavior. The CFD simulations showed a good performance on the tool joint simulations. Finally, the literature's correlations originally employed by Petrobras were used to estimate the friction factor, and new parameters for these correlations were established. The evaluation of the parameters improved the predictive capacity mostly in the laminar regime.