Viscosity and density of a two-phase drilling fluid

Many ice-core drilling projects expect to reach depths greater than 1000 m. At such depths it is necessary to fill the borehole with a fluid to compensate the ice pressure and avoid the resulting significant hole closure. Knowledge of the ice-chips and drilling-fluid circulation parameters (e.g. flow rate, pressure drop, velocity) is essential for understanding the behaviour of the fluid around the drill and will support drill design through a better parameterization in models. A characterization of the dynamic viscosity and of the density of the ice-chips and drilling-fluid mixture is required to calculate these circulation parameters. The goal of this study is to propose a method to calculate, to a first approximation, both these physical properties. The relationships presented here have been established after experimentation, building on prior assumptions taken from the literature.