Experiments on the characteristics of upgrading and viscosity reduction of heavy oil under supercritical water conditions  

作　　者：HUANG Zhongwei SHEN Yazhou WU Xiaoguang LI Gensheng LONG Tengda ZOU Wenchao SUN Weizhen SHEN Haoyang 

机构地区：[1]State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China

出　　处：《Petroleum Exploration and Development》2025年第1期170-181,共12页石油勘探与开发(英文版)

基　　金：Supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China(52421002);General Program of National Natural Science Foundation of China(52474016).

摘　　要：This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The effect of three reaction parameters,i.e.reaction temperature,reaction time and oil-water ratio,is analyzed on the product and their correlation with viscosity.The results show that the flow state of heavy oil is significantly improved with a viscosity reduction of 99.4%in average after the reaction in the supercritical water.Excessively high reaction temperature leads to a higher content of resins and asphaltenes,with significantly increasing production of coke.The optimal temperature ranges in 380–420℃.Prolonged reaction time could continuously increase the yield of light oil,but it will also results in the growth of resins and asphaltenes,with the optimal reaction time of 150 min.Reducing the oil-water ratio helps improve the diffusion environment within the reaction system and reduce the content of resins and asphaltenes,but it will increase the cost of heavy oil treatment.An oil-water ratio of 1︰2 is considered as optimum to balance the quality improvement,viscosity reduction and reaction economics.The correlation of the three reaction parameters relative to the oil sample viscosity is ranked as temperature,time and oil-water ratio.Among the four fractions of heavy oil,the viscosity is dominated by asphaltene content,followed by aromatic content and less affected by resins and saturates contents.

关 键 词：heavy oil supercritical water in-situ modification viscosity reduction influencing factors thermal recovery of heavy oil viscosity reduction for gathering and transportation 

分 类 号：TE6[石油与天然气工程—油气加工工程]