超临界蒸汽作用下特稠油的水热裂解特性实验

Extra-Heavy Oil Hydrothermal Pyrolysis Experiment with Supercritical Steam

针对超临界蒸汽作用下特稠油的水热裂解特性及其反应动力学研究不够深入的问题,运用室内实验,进行了超临界蒸汽环境下不同温度、加入气体及不同水油比等因素对特稠油水热裂解的影响研究,并对超临界蒸汽或超临界多元热流体环境中特稠油的水热裂解反应动力学特性进行了对比分析。研究表明:在超临界蒸汽或超临界多元热流体作用下,特稠油发生明显的热裂解效应,表现为饱和烃含量大幅度增加,并释放出一定量气体,原油物性明显改善,同时也生成了焦炭类物质;加入气体时,会进一步加剧焦炭物质的转化,并抑制沥青质的分解,从而减缓了沥青质的热裂解速率,不利于稠油的水热裂解反应。该研究对于深入认识超临界蒸汽提高稠油油藏采收率的机理,并促进超临界蒸汽在深层稠油油藏热力采油中的应用与推广具有实践指导意义。

Laboratory experiment test was used to further study the hydrothermal pyrolysis performances and reaction kinetics of extra-heavy oil under supercritical steam.The effects of multiple factors on the extra-heavy oil hydrothermal pyrolysis under supercritical steam were determined,including temperature,gas adding,water-oil ratio,etc.The kinetics of extra-heavy oil hydrothermal pyrolysis was also compared and analyzed under supercritical steam or supercritical multi-component thermal fluid.Result indicates that the extra-heavy oil shows a favorable thermal pyrolysis under supercritical steam or supercritical thermal-component thermal fluid condition.The extra-heavy oil pyrolysis is characterized by great increment of saturated hydrocarbons and a certain amount of gas release.The physical properties of crude oil have been significantly improved,which is also accompanied by the production of coke classes.Gas adding further aggravate the conversion of coke classes and inhibits the decomposition of asphaltenes,which slows the thermal pyrolysis rate and is unfavorable to the hydrothermal pyrolysis of extra-heavy oil.This research could provide certain practical guidance for understanding the enhancing oil recovery mechanisms in heavy-oil reservoir with supercritical steam and the application-promotion of supercritical steam in the thermal recovery of deep heavy oil reservoir.