94% of researchers rate our articles as excellent or good
Learn more about the work of our research integrity team to safeguard the quality of each article we publish.
Find out more
ORIGINAL RESEARCH article
Front. Earth Sci.
Sec. Geochemistry
Volume 13 - 2025 | doi: 10.3389/feart.2025.1541669
Quantitative Assessment of the Genetic Types and Sources of Natural Gas in Well Y5 of the North Slope of Baiyun Sag
Provisionally accepted
Xudong Wang 1,2,3*
Nansheng Qiu 3* Xiangtao Zhang 1,2* Guangrong Peng 1,2*
Cong Chen 1,2 Yinglin Zhang 1,2*- 1 Shenzhen Branch of China National Offshore Oil Corporation, Shenzhen, China
- 2 CNOOC Deepwater Development, Shenzhen, China
- 3 State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum (Beijing) ）, Beijing, China
The exploration of natural gas in the Baiyun Sag of the Pearl River Mouth Basin (PRMB), South China Sea have attracted extensive attentions in recent years. However, considerable controversy remains regarding the origin and main source rocks for the discovered natural gas in this area. In this study, we established a quantitative method for distinguishing the origin and source rock of natural gas by combining geochemical indicators and chemical kinetics. The results show that the natural gas in the Well Y5 block on the northern slope of Baiyun Sag was of thermogenic origin and are mainly derived from Paleogene source rocks with minor contribution of natural gas generated by oil cracking below layer ZH440. The crude oil cracking gas accounts for approximately 6%. The mixture of kerogen degradation gas with a small amount of crude oil cracking gas caused an inversion in the carbon isotope sequence of ethane and propane. The natural gas in the well Y5 area was mainly generated from delta and shallow lake source rocks after 11 Ma. The findings suggest that natural gas was accumulated in shallow, high-quality reservoirs in the early stage and deep, tight reservoirs in the late stage.
Keywords: Baiyun sag, thermal simulation, Chemical kinetics, Carbon isotope composition, Natural gas genesis
Received: 08 Dec 2024; Accepted: 11 Feb 2025.
Copyright: © 2025 Wang, Qiu, Zhang, Peng, Chen and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Xudong Wang, Shenzhen Branch of China National Offshore Oil Corporation, Shenzhen, China
Nansheng Qiu, State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum (Beijing) ）, Beijing, China
Xiangtao Zhang, Shenzhen Branch of China National Offshore Oil Corporation, Shenzhen, China
Guangrong Peng, Shenzhen Branch of China National Offshore Oil Corporation, Shenzhen, China
Yinglin Zhang, Shenzhen Branch of China National Offshore Oil Corporation, Shenzhen, China
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.