The present work provides high-resolution modeling of the thermal maturation of the Eocene Thebes Formation using a multi-1D approach. The model focuses not solely on the thermal maturity but also on timing of hydrocarbon generation (primary generation and secondary cracking), adsorption by organic matter, and expulsion. The time-lapse conceptual model was developed using well log data, geochemical analyses, and composite logs. The stratigraphic sequence of the Belayim Marine oil field was subdivided into a time series based on the tectonic framework of the Gulf of Suez. An elevated basal heat flow has been assigned throughout the rifting phases and basin evolution. The simulation developed for seven wells reveals variations in burial, thermal history, and accordingly the thermal maturity. The predicted thermal maturity ranges from immature to mature with a different tendency to generate hydrocarbons (both primary generation of oil and/or gas secondary cracking) dependent on kerogen type, basin development, and burial history. Hydrocarbon generation (oil) starts after the Messinian Time Event during the deposition of the Post-Zeit Formation. Hydrocarbon generation was related to burial rather than basin evolution for the 113-M-27, BM-23, BM-65, and BM-70 wells. Conversely, generation correlated principally to basin development particularly Messinian Time Event for the 113-M-34 well. Expulsion occurred subsequent to generation of thermogenic gas (secondary cracking of generated oil). It is not possible to investigate the relationship between the production index and thermal maturity as a consequence of expulsion that reduced the S1 values. The different levels of thermal maturity (potential, active, and effective source rock) allow for the differentiation of regions of potential hydrocarbon accumulation that were charged from the Thebes Formation.
Keywords
Thermal maturity level Thebes formation Petroleum system modeling Belayim marine oil field Gulf of Suez Organofacies Conductive cooling
This is a preview of subscription content, log in to check access.
Notes
Acknowledgments
The authors would like to thank the Egyptian General Petroleum Corporation (EGPC) and Belayim Petroleum Company (Petrobel) for providing the material, the geo-related information, and all the digital logs. The authors also acknowledge the Schlumberger Company for the use of PetroMod® software applications. The authors would like to thank Dr. H. El-Atfy for his valuable insights and recommendations that helped with a better understanding of the basin geology. The article has profited from discussion with Dr. T. Anan at the Geology Department and reviews by Prof. Dr. A. Kamel. The authors are also very thankful for the constructive comments of the anonymous referees and suggestions made by editor-in-chief and internal critical (potential) reviewers, which have significantly improved this article. |
