Title: Jurassic hydrocarbon accumulation period division in Huanjiang oilfield: evidence from fluid inclusions

Authors: Dong Hao; Zhiwei Liu; Li Qu; Yunhai Bai; Zhaobing Chen; Quyang Liu

Addresses: PetroChina ChangQing Oilfield Company, Exploration and Development Research Institute, Xi'an, Shaanxi 710018, China; National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields, Xi'an, Shaanxi 710018, China ' PetroChina ChangQing Oilfield Company, No. 7 Oil Production Plant, Xi'an, Shaanxi 710200, China ' PetroChina ChangQing Oilfield Company, No. 7 Oil Production Plant, Xi'an, Shaanxi 710200, China ' National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields, Xi'an, Shaanxi 710018, China; CNPC Chuanqing Drilling Engineering Company Ltd., Drilling and Production Technology Research Institute, Xi'an, Shaanxi 710018, China ' School of Earth Science and Engineering, Xi'an Shiyou University, Xi'an 710065, China ' PetroChina ChangQing Oilfield Company, No.7 Oil Production Plant, Xi'an, Shaanxi 710200, China

Abstract: This study provides a detailed description and quantitative analysis of Jurassic hydrocarbon inclusions in the Huanjiang area in the Ordos Basin through fluid inclusion analysis and homogenisation temperature measurement, revealing the hydrocarbon filling process and accumulation stages of the sandstone oil reservoir. The results show that oil pool of the Yan'an Formation is generally accumulated with mature and highly mature hydrocarbon, with the later one being the main period, and is characterised by filling sequence from bottom to top. Each layer exhibits obvious characteristics of two stages hydrocarbon filling, with the oil pool forming period being the Early Cretaceous, and the main filling period being the middle to late Early Cretaceous, which is basically consistent with the main hydrocarbon accumulation period of the basin. This indicates that the western margin thrust structure is dominated by uplifted, while the source rocks have not undergone further subsidence for hydrocarbon generation and expulsion. [Received: May 7, 2024; Accepted: June 14, 2024]

Keywords: Jurassic; Huanjiang area; Ordos basin; fluid inclusion; hydrocarbon accumulation.

DOI: 10.1504/IJOGCT.2025.145470

International Journal of Oil, Gas and Coal Technology, 2025 Vol.37 No.3, pp.301 - 320

Received: 24 Apr 2024
Accepted: 14 Jun 2024
Published online: 01 Apr 2025 *

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