基于剪切速率匀速加载条件的含蜡原油屈服-触变特性  

Yield-thixotropy of waxy crudes under uniform rate of shear rate sweep

作　　者：国丽萍[1,2] 张劲军[1] 

机构地区：[1]中国石油大学(北京)城市油气输配技术北京市重点实验室,北京102249 [2]东北石油大学石油工程学院,黑龙江大庆163318

出　　处：《大庆石油学院学报》2011年第3期72-75,119,共4页Journal of Daqing Petroleum Institute

基　　金：国家“863”高科技项目(2006AA09Z357);北京市优秀博士学位论文指导教师科技项目(YB20081141401)

摘　　要：屈服-触变性是胶凝含蜡原油重要的依时流变特性,利用RS150H流变仪对大庆原油、中原原油、大庆-南堡混合油、苏丹原油等4种物性不同的含蜡原油,在剪切速率线性增大后又线性减小循环加载方式条件下,研究胶凝含蜡原油的屈服-触变性,给出屈服时间与剪切速率变化率之间关系的经验表达式.结果表明:在该循环加载条件下,蜡晶结构恢复速率较慢,在研究含蜡原油的滞回环时应该主要考虑第一个环.同一温度下,当剪切速率变化率变大时,滞回环向离开剪切速率轴方向移动,环的面积变大;当剪切速率变化率变小时,滞回环向剪切速率轴方向移动,环的面积变小.随着剪切速率变化率的降低,屈服应力减小,屈服时间延长.Yield-thixotropy is an important time dependent rheological behavior of gelled waxy crudes.In order to study the yield-thixotropic behavior of gelled waxy crudes under cyclic shearing of linear increasing and decreasing of shear rate,four different types of waxy crude oil were studied experimentally by using RS150H rheometer.It is found that because the recovery rate of wax crystal structure is slow,study should be focus on the first loop.At a certain temperature,the hysteresis loop moves away from the shear rate axis and the area of the loop becomes larger with increased rate of shear rate sweep;and vice versa,the loop moves toward the shear rate axis and the area of the loop becomes smaller with decreased rate of shear rate sweep.And the yield stress is also reduced and the yielding time increased with decreased rate of shear rate sweep.In addition,based on the experimental results an empirical correlation is developed to describe the relationship of yielding time and rate of shear rate sweep.

关 键 词：含蜡原油 触变性 滞回环 屈服应力 屈服时间 

分 类 号：TE622.1[石油与天然气工程—油气加工工程]