摘要
析蜡点是表征原油析蜡过程的一个重要参数。根据析蜡后由于分散相蜡晶的出现 ,粘性流动活化能就增大这一特点 ,提出了依据活化能的增加确定析蜡点温度的方法 ,并将该方法与其它三种方法 (旋转粘度计法、差示扫描量热 (DSC)法、显微观察法 )进行了对比分析。结果表明 ,旋转粘度计法不适用于测定初始析蜡速率较慢、以及含蜡量少的原油 ;DSC法具有简便、耗样量少、再现性好的优点 ;显微观察法确定的析蜡点与试片厚度及透光亮度有关 ,其结果受主观因素影响 ;依据活化能的增加确定原油析蜡点 ,数据可直接取自原油粘温曲线 ,其结果与DSC法确定的析蜡点基本一致 。
Wax appearance temperature (WAT) is an important parameter for waxy crude oils. Viscometry,differential scanning calorimetry (DSC), and polarization thermomicroscopy are main methods used to determine the WAT. The dynamic viscosity in the Newtonian temperature range of the crude oils generally obeys a simple Arrhenius type of temperature dependence. Activation energies of viscous flow will increase after wax precipitation from oils,and the WAT can be evaluated from the increment of the activation energies. The results of WAT of crude oils determined by viscometry, DSC, thermomicroscopy, and from the increment of the activation energies are compared and discussed. It is concluded that viscometry should not be used to determine the WAT of crude which has characteristic of slow precipitation of wax or low wax content. DSC has the strengths of simpleness, less sample amount and good repeatability. WAT from ther-momicroscopy depends on factors such as thickness of the sample and light intensity.WAT evaluated from the increment of the activation energies is simple and has good repeatability. Good agreement is obtained among the DSC,thermomicroscopy and from the increment of the activation energies.
出处
《油气储运》
CAS
北大核心
2003年第10期28-30,39,共4页
Oil & Gas Storage and Transportation
关键词
含蜡原油
析蜡点
粘温特性
活化能
输油管道
crude oil, technology, wax appearance temperature, viscosity-temperature characteristics, activation energy, comparison, research
