The Study On The Methord Of Describing The Thixotropy Model Of Waxy Crude Oil

The thixotropic model is a mathematical representation of thixotropy.In practical engineering cases and laboratory studies,the thixotropic model provides a quantitative analysis of the thixotropy of waxy crude oil,which is very important for practical engineering calculations and applications.This paper summarizes and investigates the research status of thixotropy and thixotropy model of waxy crude oil.Based on the commonly used Houska model,a new 5-parameter model describing the thixotropy of waxy crude oil is derived.This new model contains no structural parameter ?,avoiding the problem that the structural parameter in the structural dynamics equation is difficult to determine,simplifying the equation,making it simple and intuitive and having good fitting accuracy.The thixotropy curves of Daqing crude oil and two kinds of crude oil in the reference literature were verified and error analysis.The results show that the method can accurately describe the thixotropy of waxy crude oil at constant temperature.In addition,based on the Houska model and the derived 5-parameter model,this paper proposes a method to describe the thixotropy of waxy crude oil at different shear rates at a constant temperature based on the shear step curve.The experimental method only needs to use the oil sample once,and the thixotropic equation can be determined based on only one complete thixotropy curve and shear stress balance value of several shear rates,which avoids the influence of shear stress fluctuation on the experimental results during shear stress cracking and simplifies the experiment and improves the experimental efficiency.This new model can predict the complete thixotropy curve at any shear rate.This paper verifies the model with four different kinds of waxy crude oil.The method for describing the thixotropy of waxy crude oil is simple and intuitive.