Evolution of organic carbon isotopes during the pyrolysis of Nongan oil shale in Songliao Basin and its implications for in-situ conversion project

Mastering the reaction process of underground pyrolysis is the key to oil shale in-situ conversion project. The progress of the pyrolysis reaction can be analyzed by the information of the kerogen maturity in the reaction formation. However, it is difficult to directly test the kerogen maturity by drilling and coring in in-situ conversion project. And the research on judging the process of underground pyrolysis reaction according to the maturity of oil and gas products has not been carried out in depth. This project intends to take the oil shale of the Nenjiang Formation in the southern Songliao Basin and the pyrolysis oil samples produced by the in-situ conversion project as the research object, and conduct simulation experiments and test analysis. The purpose of this paper is to identify the dynamic evolution characteristics of carbon isotope fractionation during the evolution of oil shale pyrolysis hydrocarbon products, and then establish the response relationship with the process of oil shale organic matter pyrolysis. This study has formed a set of dynamic monitoring methods for the in-situ conversion of oil shale to organic matter pyrolysis reaction process, and laid a theoretical foundation for the efficient, economical and stable operation of oil shale in-situ conversion projects.

Automated summary

Mastering the reaction process of underground pyrolysis is vital for oil shale in-situ conversion projects. However, directly testing the kerogen maturity and judging the pyrolysis reaction process according to oil and gas product maturity is challenging in in-situ conversion projects. This study aims to simulate and analyze oil shale and pyrolysis oil samples from the Nenjiang Formation in the southern Songliao Basin to identify the dynamic evolution characteristics of carbon isotope fractionation during oil shale pyrolysis and establish a response relationship. The study has developed a set of dynamic monitoring methods for the in-situ conversion of oil shale, laying a theoretical foundation for efficient and stable operation of such projects.