A Novel Thixotropy Model for Waxy Crude Oil

A novel four-parameter hyperbolic thixotropy model based on the analysis of data obtained from tests and literatures is presented. The model has many advantages such as high accuracy, extensive applicability and definite physical meaning. It is shown by the tests on the viscometers and model loop-line test apparatus that the thixotropy of waxy crude oil under certain temperature and constant shear rate can he described well by the model. The effect of start-up shear rate on the yield stress and balanced shear stress is analyzed.