摘要
触变性是含蜡原油的一个重要流变特性,对输油管道停输再启动过程的水力特性及安全性至关重要。通过实验,研究了4种含蜡原油在剪切速率先呈线性增大后呈线性减小这一循环加载条件下的滞回环特性。利用最小二乘原理,分别对剪切速率循环一次得到的单一滞回环和剪切速率变化率不同的多个循环得到的多个滞回环进行了拟合。用平均偏差作为统计指标,对8个触变模型进行了评价。结果表明,基于Cheng的含蜡油品中存在完全可逆和完全不可逆两类结构,在Houska模型的基础上建立的模型最适合于描述含蜡原油的滞回环特性。
The thixotropy of waxy crude is an important rheological behavior to the hydraulic characteristics and safety in the restart process of oil pipelines.The hysteresis loops of four types of waxy crude were experimentally studied under the cyclic shearing condition of firstly increasing in linear pattern and then decreasing of shear rate.The data of single hysteresis loop obtained from the shear rate of one cycling and the multiple loops obtained from the shear cycling at various shear rates were fitted respectively using the least square.The average absolute deviation was taken as the statistical index to the experimental data.Eight thixotropy models were evaluated by the least-square regressions.Among eight models,five ones are developed specially for waxy crudes,and the other three ones are developed for human blood and proved to be suitable for describing the hysteresis loop.It is concluded that the most suitable model for describing the characteristics of hysteresis loop is developed from Cheng＇s idea on the basis of the Houska model about two kinds of structures（reversible and irreversible structures） existing in waxy oils.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2010年第3期494-500,共7页
Acta Petrolei Sinica
基金
国家高技术研究发展计划(863)项目(2006AA09Z357)
北京市优秀博士学位论文指导教师科技项目(YB20081141401)联合资助
关键词
输油管道
含蜡原油
滞回环
触变模型
评价
oil transition pipeline waxy crude hysteresis loop thixotropy model assessment
