胶凝大庆原油不同加载时间下的屈服特性  

Yielding characteristics of gelled Daqing crude oil on different stress loading time

作　　者：彭建伟[1] 韩善鹏[1] 张劲军[1] 侯磊[1] 

机构地区：[1]中国石油大学城市油气输配技术北京市重点实验室,北京102249

出　　处：《中国石油大学学报（自然科学版）》2008年第4期109-113,117,共6页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：教育部科学技术研究重点项目(104118)

摘　　要：为得到胶凝大庆原油的屈服过程与加载时间之间的关系,利用Haake RS-150控制应力流变仪通过恒剪切应力、剪切应力匀速增加和阶跃式增加3种不同的加载方式对其屈服过程进行了实验。研究发现:胶凝大庆原油的屈服过程与加载时间存在密切关系,屈服是变形随时间积累的结果;加载过程中各水平的应力作用时间延长,所得到的胶凝原油屈服应力下降,但屈服所需的时间延长,即应力值与作用时间相互弥补,在一定范围内小应力长加载时间和大应力短加载时间都能造成胶凝原油屈服;对剪切应力阶跃式加载而言,屈服应力随每阶段持续作用时间(单阶作用时间)的增加呈指数规律下降,屈服时间随单阶作用时间增加在双对数坐标中呈线性增加。In order to acquire the relationship between the yielding of gelled Daqing crude oil and stress loading time, the control stress rheometer （ Haake RS-150） was used, with the shear stress loading in three different ways： constant, ramp and stepwise sequence. The results show that the yielding of gelled Daqing crude oil closely depends on the loading time of shear stress. The yielding is the result of the accumulation of deformation with time. The yield stress of gelled crude oil decreases with the increase of time duration of shear stress at each level, but the time needed for yielding is prolonged. The values of shear stress and time duration complement each other, and either the low shear stress with long time duration or the high shear stress with short time duration can lead to the yielding of gelled crude oil in a range. For the shear stress loading in a stepwise way, the yield stress decreases exponentially with the increase of time duration in each step, and the yielding time increases linearly with the time duration increasing in each step in log-log scale coordinates.

关 键 词：大庆原油 屈服 应力加载时间 剪切应力 屈服应力 屈服时间 

分 类 号：TE832.3[石油与天然气工程—油气储运工程]