TITLE:
Evaluation of Thixotropic Models for Waxy Crudes
AUTHORS:
Liping Guo, Xu Chen, Shuang Shi, Yu Wang, Xiaoyang Yu
KEYWORDS:
Waxy Crude Oils, Thixotropy, Thixotropic Model
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.5 No.6,
June
26,
2015
ABSTRACT: Thixotropy is a great rheological behavior of waxy crudes oils and is of great importance for hydraulic characteristics and security of oil pipeline restart. In this paper, through the experiment of four waxy crudes, three kinds of thixotropic rheology characteristics in the conditions that shear stress decays under a constant shear rate, shear stress decays after shear rate steps up and hysteresis loop of shear rate cycle changes are studied . For eight thixotropic models, experimental data are fitted in the method of least-squares and average deviation is taken as a statistical indicator to evaluate the thixotropic models. It shows that the model with the idea of Cheng that completely reversible and totally irreversible structures both exist in waxy oil products and based on Houska model can describe thixotropic behaviors of waxy crudes most well.