Organic Geochemistry and Oil‐Source Correlations in the Carboniferous Yanghugou Formation in the Yindongzi Area, Ordos Basin, China

ABSTRACT In recent years, extensive oil and gas exploration in the Ordos Basin has led to the discovery of oil reservoirs within the Carboniferous Yanghugou Formation in the basin's southwestern margin. This study investigates the organic geochemical characteristics and oil‐source correlations in the Yanghugou Formation, aiming to clarify the origin of crude oil in this formation by comparing samples from both the Yanghugou and Wulalike formations. Geochemical analyses reveal that the Yanghugou Formation source rocks exhibit high organic matter content, low maturity, and a freshwater‐oxidising environment, with contributions from both land plants and aquatic organisms, suggesting significant potential for oil generation. Conversely, the Wulalike Formation source rocks exhibit lower organic matter content, higher maturity, and a brackish water‐weakly reduced environment, reflecting a more moderate oil‐generating potential. The study uses biomarkers and multivariate statistical methods, including cluster analysis and Q‐factor analysis, to establish that the oil in the Yanghugou Formation is a mixed‐source oil, originating from both the Yanghugou and Wulalike source rocks. The results highlight the importance of combining geochemical parameters and statistical techniques to improve oil‐source correlations and aid exploration strategies in the southwestern Ordos Basin. This study provides new insights into the complex hydrocarbon accumulation mechanisms in the area and offers valuable information for future exploration efforts.