热处理温度对长庆原油蜡沉积特性的影响

Effect of Thermal Treatment Temperature on Wax Deposition Property of Changqing Crude Oil

通过Couette蜡沉积装置及DSC热分析探究了热处理温度对长庆原油蜡沉积特性的影响,发现随着热处理温度的升高,长庆原油蜡沉积速率减缓,蜡沉积层老化速率加快;经50℃和60℃热处理的长庆原油,蜡沉积层出现了分层现象,其表层为流动性较强的凝油状蜡沉积层,底层为结构较为致密的类固态蜡沉积层;经70℃热处理的长庆原油,蜡沉积层极薄且致密,无分层现象,其表面无凝油状蜡沉积层。采用沥青质分散程度分析、DSC热分析及蜡晶形貌显微观察探究了其影响机理,发现随着热处理温度的升高,长庆原油沥青质分散程度增大,从而使其析蜡点降低,蜡晶团聚性增强,原油低温流动性得以改善,进而对其蜡沉积特性产生了显著影响。

The effect of thermal treatment temperature on wax deposition property of Changqing waxy crude oil was detailedly studied through a Couette wax deposition device and DSC analysis.It was found that with the increase of thermal treatment temperature,the wax deposition rate of the crude oil can be inhibited obviously and the aging rate of the wax deposits can be accelerated.The formed wax deposits at the thermal treatment temperatures 50℃and 60℃become two-layer structures,with a thin/hard inner layer and a relatively thick/soft outer layer.When the thermal treatment temperature rises to 70℃,the formed wax deposit is too thin to identify the two-layer structure.Then,the influencing mechanism of thermal treatment temperature on wax deposition property of Changqing waxy crude oil was detailedly studied through asphaltenes dispersibility test,DSC analysis and microscopic observation.The results showed that increasing the thermal treatment temperature can greatly improve the dispersibility and activity of the asphaltenes in crude oil,the activated asphaltenes has stronger interactions with waxes and then changes the precipitated wax crystals’morphology,thus greatly improving the crude oil flowablility,which has a significant effect on wax deposition property of Changqing waxy crude oil.