Geochemistry of High-Maturity Crude Oil and Gas from Deep–Ultradeep Reservoirs and Their Geological Importance in a Foreland Basin: A Case Study of the Southern Thrust Belt, Junggar Basin, Northwest China

作者：Gang Liu, Jianzhong Li, Xuefeng Qi, Ming Zhu · 发表于：Journal of Energy Engineering · 年份：2023 · DOI：10.1061/jleed9.eyeng-4766 · 被引用次数：6 · 研究领域：Hydrocarbon exploration and reservoir analysis、Atmospheric and Environmental Gas Dynamics、Methane Hydrates and Related Phenomena

In the southern thrust belt (STB) of Junggar Basin, hydrocarbon resources are abundant at ultradeep depths. The genesis of highly mature oil and gas is complex, with considerable geological implications, because of the burial depth of these resources and multiphase tectonic evolution. The deep–ultradeep oil and gas reservoir accumulation processes and the contribution of Permian source rocks are still unclear in the STB. In this study, using the ultradeep reservoirs of the middle section of the STB (MSTB) as an example, systematic evaluations were conducted on the hydrocarbon geochemical characteristics of the area. Additionally, this study detailed the accumulation and evolution processes of the reservoir in the lower play of the MSTB using various comprehensive technical analyses, such as those for the geochemical characteristics of crude oil, the genesis and source of crude oil and gas, inclusion observations, homogenization temperature, quantitative particle fluorescence, and basin simulation. The integrated analysis results showed that the oil and gas from Well HT-1 in Huxi Anticline (HXA) in the lower play was characterized by mixed sources from Permian argillaceous source rock and Jurassic coal-bearing source rocks. The pristane/phytane ratio (Pr/Ph) and biomarkers of the crude oil indicated the presence of Permian source crude oil. The natural gas drying coefficient and the carbon isotope of methane conveyed a typical coal-related gas from the Lower–Middle Jurassic ep...