Lab Investigations into High Temperature High Pressure Rheology of Water-Based Drilling Fluid

HTHP rheology was investigated for the water-based drilling fluid applied in Yuanba region of Southwest Gas Fields in China. The results showed that under the conditions of temperature up to 180°C and pressure up to 100MPa, the Bingham plastic model is adequate to predict transient rheology at the given HTHP conditions. Effects of temperature on rheology are more dominant than that of pressure, but the latter will enhance at high temperatures and low shear rates. Finally, HTHP viscosity models were established and evaluated for water-based drilling fluid.