TY - JOUR
T1 - Restoration of buried organic carbon for catagenesis-affected rocks using Rock-Eval thermal analysis
T2 - Assumptions, performance, and uncertainty analysis
AU - Wang, Qianyou
AU - Li, Yaohua
AU - Sanei, Hamed
AU - Rudra, Arka
AU - Yuan, Ming
AU - Wang, Yang
AU - Huang, Yizhou
AU - Worden, Richard H.
N1 - Publisher Copyright:
© 2024
PY - 2025/8
Y1 - 2025/8
N2 - Total organic carbon (TOC) content, a classic indicator of rock organic richness, is widely used in geological archives for paleoenvironmental interpretation and petroleum system modeling. However, organic carbon (OC) undergoes significant alteration and loss upon burial, rendering present-day TOC measurements inadequate for reflecting original OC levels. Many approaches have been developed to restore such OC loss based on mass balance principles and Rock-Eval parameters, yet these methods rely on implicit assumptions that introduce uncertainties and have not been tested. Based on a reevaluation of previous restoration methods, this study proposed a mass balance framework with a refined algebraic scheme to reconstruct buried (pre-catagenesis) TOC. A one-at-a-time sensitivity analysis method was introduced to quantify the propagation uncertainties in the model by examining the responses of TOC restoration outputs (TR, f, and σTOC) to variations in key inputs (TOCpd, BIpd, HIpd, HIo, Cc, α, and β). Simulated Rock-Eval data, derived from HI-Tmax sigmoid models, was utilized in sensitivity analysis to avoid the influence of source rock heterogeneity and organo-facies variations. Both the simulated and experimental results demonstrate that the proposed model improves the TOC restoration accuracy by accounting for the rock mass changes and OC deductions due to hydrocarbon expulsion. Furthermore, the uncertainties arising from S1 “carry-over” and mineral matrix effects are resolved through the new equations. This study, from a sensitivity analysis perspective, summarizes the impacts of input parameters in perspectives of kerogen kinetics and thermal maturation, offering a guideline for more robust TOC restoration and evaluation.
AB - Total organic carbon (TOC) content, a classic indicator of rock organic richness, is widely used in geological archives for paleoenvironmental interpretation and petroleum system modeling. However, organic carbon (OC) undergoes significant alteration and loss upon burial, rendering present-day TOC measurements inadequate for reflecting original OC levels. Many approaches have been developed to restore such OC loss based on mass balance principles and Rock-Eval parameters, yet these methods rely on implicit assumptions that introduce uncertainties and have not been tested. Based on a reevaluation of previous restoration methods, this study proposed a mass balance framework with a refined algebraic scheme to reconstruct buried (pre-catagenesis) TOC. A one-at-a-time sensitivity analysis method was introduced to quantify the propagation uncertainties in the model by examining the responses of TOC restoration outputs (TR, f, and σTOC) to variations in key inputs (TOCpd, BIpd, HIpd, HIo, Cc, α, and β). Simulated Rock-Eval data, derived from HI-Tmax sigmoid models, was utilized in sensitivity analysis to avoid the influence of source rock heterogeneity and organo-facies variations. Both the simulated and experimental results demonstrate that the proposed model improves the TOC restoration accuracy by accounting for the rock mass changes and OC deductions due to hydrocarbon expulsion. Furthermore, the uncertainties arising from S1 “carry-over” and mineral matrix effects are resolved through the new equations. This study, from a sensitivity analysis perspective, summarizes the impacts of input parameters in perspectives of kerogen kinetics and thermal maturation, offering a guideline for more robust TOC restoration and evaluation.
KW - Catagenesis
KW - Pyrolysis
KW - Rock-Eval
KW - Source rock
KW - Thermal maturation
KW - TOC restoration
UR - https://www.scopus.com/pages/publications/105004808089
U2 - 10.1016/j.earscirev.2025.105155
DO - 10.1016/j.earscirev.2025.105155
M3 - Review
AN - SCOPUS:105004808089
SN - 0012-8252
VL - 267
JO - Earth-Science Reviews
JF - Earth-Science Reviews
M1 - 105155
ER -