含蜡原油触变模型研究现状

Review of the thixotropic models for waxy crude

黏弹-触变特性是含蜡原油重要的流变特性,对输油管道停输后再启动过程的水力特性及管道运行安全具有重要影响。介绍了含蜡原油黏弹-触变特性的成因、机理和特点,总结了常用触变性测试方法及优缺点。评述了现有触变模型的研究现状,分析了现有黏塑性触变模型和黏弹-触变模型的特点与缺陷。对于目前最常用的结构动力学类触变模型,阐述了采用单一结构参数存在的问题,详尽分析了现有速率方程的一些数学特性及其存在的缺陷,总结了现有的一些改进方法。

The viscoelastic-thixotropic property is an important rheological property of waxy crude oils.It has important impact on the restart safety and flow recovery of crude oil pipelines.The paper introduces the causes,mechanism,and characteristics of the viscoelastic-thixotropic property,and summarizes the commonly used thixotropic test methods along with their individual advantages and disadvantages.The existing thixotropic models are reviewed,and the characteristics and defects of the existing viscoplastic-thixotropic and viscoelastic-thixotropic models are analyzed in detail.For the structural kinetics models,the problems of using a single scalar parameter to characterize the micro-structure are discussed.And the mathematical characteristics and defects of the commonly used kinetic equations are illustrated,furthermore the improvement methods solving those problems are summarized.