A new thixotropic model for waxy crude

作者：Teng, Houxing; Zhang, Jinjun^*

来源：Rheologica Acta, 2013, 52(10-12): 903-911.

DOI：10.1007/s00397-013-0729-z

• Thixotropy
• Thixotropic model
• Kinetic equation
• Model validation
• Waxy crude

Waxy crude oil shows thixotropic behavior below the gelation temperature. The mostly used thixotropic model for waxy crude is the model proposed by Houska. One problem of Houska's model is that after the stepwise change in shear rate, the predicted shear stress decreases to its equilibrium value more quickly than the measured data. To address this problem, a new viscoplastic thixotropic model is proposed. The evolution of structural parameter is described by a new kinetic equation. In the kinetic equation, a new pre-factor with shear strain as variable is introduced for the buildup and breakdown terms, and the breakdown term is assumed to be dependent on energy dissipation rate rather than on shear rate. The proposed model was validated by the stepwise shear rate test and hysteresis loop test. And the results showed that the new model's fitting and predictive capability is satisfactory.

• 出版日期2013-11
• 单位中国石油大学（北京）