The time-temperature-maturity relationship: A chemical kinetic model of kerogen evolution based on a developed molecule-maturity index

FUEL

卷:278

Article

Wang, Xiaohe^1,2  Zhao, Ya-Pu^1,2 

[1] Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China

[2] Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China

关键词: Kerogen thermal evolution;    Kerogen maturity index;    Vitrinite reflectance;    Chemical kinetic model;    Activation energy;   

DOI  :  10.1016/j.fuel.2020.118264

来源: Elsevier

【 摘 要 】

Kerogen maturity is an important indicator for evaluating source rocks. We propose a kerogen maturity index (molecule-maturity index, MMI) based on the changes in the molecular structure of organic matter during thermal evolution. The MMI has a positive correlation with vitrinite reflectance. Molecular dynamics simulations indicate that the weight loss is with a positive linear correlation with the MMI, demonstrating the ability of the index to reflect the hydrocarbon generation of organic matter. In addition, a new conversion is introduced by the MMI to analyze the kinetics of kerogen thermal evolution. The activation energy is expressed as a continuous function of the MMI linking by the new conversion. The activation energy was calculated at the isoconversional points of previous conversion, which was not defined as a continuous function before. A linear relationship between the activation energy of kerogen is observed, and a new chemical kinetic model of kerogen thermal maturity is established based on the MMI (kinetic model of the maturity evolution, MEKM). The MEKM equation has a simple form and is convenient for engineering applications. Our findings provide insights into the kinetics of kerogen thermal maturation and guide the choice of temperature and time for artificial maturity.

【 授权许可】

Free