Stribeck performance of drilling fluids for oil and gas drilling at elevated temperatures

摘要

In oil and gas drilling, the borehole temperature can be as high as 200 degrees C. Using a high pressure and high temperature drilling fluid tribometer, two different lubricant additives (Additives A and B) were introduced to reduce the coefficient of friction (COF) of the drilling fluid. Stribeck curve analysis at 125 degrees C shows that the sliding speed does not affect the dynamic COF and the oscillatory movement yielded relatively high static COF. Oscillatory and low speed movements were employed to study temperature effects, which showed Additive A exhibiting better tribological performance (26% and 9% static and dynamic COF reductions at 150 degrees C). Wear mechanisms were identified by scanning electron microscopy after the tribological experiments.