Study on the settling velocity of drilling cuttings in the power law fluid

Cuttings settle down freely in the drilling fluid due to the density difference when drilling fluid circulation is stopped. Further study of cuttings settling movement helps to predict the risks in hole cleaning. In this paper, cuttings settling experiments are carried out in PAM solution whose rheological property is in accordance with power law model. Three axis diameters of cuttings are obtained by CT scan. Based on experimental data regression, a new prediction model of the settling velocity in the power law fluid is obtained. The absolute average error between the new prediction model and the experiments data is 8.46%. The simulation results show the settling velocity of the cuttings in the power law fluid greatly deviates from in the Newtonian fluid under the same assumption, which indicates cuttings shape and rheological property of drilling fluid have a great influence on settling velocity. (C) 2019 Published by Elsevier B.V.