蜡、胶质沥青质对易凝原油析蜡特性及凝点影响研究

Effect of Wax and Colloidal Asphaltene on Wax Precipitation Characteristics and Pour Point of Condensable Crude Oil

易凝原油在我国原油中占比较大,一直是我国储运研究者的关注重点,对其凝点、析蜡特性的研究也是提高管输运行经济性的关键。介绍了塔里木油的密度、凝点、黏温关系及四组分,分析其作为胶质沥青质组分来改变人工蜡油配比的可行性。接着通过改变柴油、石蜡、塔里木油的配比获得不同组成比例的人工蜡油。然后以人工蜡油为实验对象,观察了不同蜡、胶质沥青质比例下,析蜡特性及凝点的变化情况。结果表明:随胶质沥青质含量的增加,凝点、析蜡点、析蜡量下降,但下降速率逐渐变缓;随石蜡含量的增加,凝点、析蜡点、析蜡量上升,但上升速率逐渐变缓。最后给出了具体理论分析,并指出了胶质沥青质的降凝重要性。

Condensable crude oil accounts for a large proportion in China’s crude oil. It has been the focus of Chinese storage and transportation researchers. The key to improve the economy of pipeline transportation is also to study the characteristics of condensation point and wax evolution of the condensable crude oil. Firstly, the density, pour point, viscosity-temperature relationship and four components of Tarim oil were introduced, and the feasibility of changing the ratio of artificial wax oil with Tarim oil as a component of colloidal asphaltene was analyzed. Then, different proportion of artificial wax oil was obtained by changing the ratio of diesel oil, paraffin oil and Tarim oil. Then, taking the artificial wax oil as the experimental object, the characteristics of wax evolution and the change of condensation point were observed under the different proportion of wax and colloidal asphaltene. The experimental results showed that, with the increase of colloidal asphaltene content, the condensation point, wax precipitation point and wax precipitation amount decreased, but the decline rate gradually slowed down. With the increase of paraffin content, the condensation point, wax precipitation point and wax precipitation amount increased, but the rising rate gradually slowed down. Finally, the concrete theoretical analysis was given, and the importance of colloidal asphaltene to reduce the setting was pointed out.