| Summary: | The Tianjingshan Paleo-uplift (TJS PU) area in the northern segment of Western Sichuan Depression (NSWSCD) has abundant oil and gas shows. The traceability of paleo-oil reservoirs and their destruction are of great significance to the study of the characteristics and mechanism of deep hydrocarbon accumulations. This study focuses on the tectonic evolution of Mianyang-Changning Intracratonic Sag (MY-CN IS) and TJS PU. The Cambrian-Ordovician tectonic movement was significant in the NSWSCD, as indicated by the formation of the TJS PU. From tension to compression tectonic-sedimentary evolution, the TJS PU is an important node in the Early Paleozoic. The analysis of deep marine hydrocarbon geological characteristics in the NSWSCD shows that the Lower Cambrian Maidiping-Qiongzhusi formations are the best source rock. Reservoir bitumen in the Dengying Fm is used as a template to identify organic geochemical parameters of paleo-oil reservoir systems with different layers and different phases in the TJS PU area. Organic carbon isotope and biomarker compounds indicate that the main source of paleo oil reservoirs is the Lower Cambrian organic-rich black shale, and the concept of "Tianjingshan Paleo-uplift paleo-reservoir system" is finally established. According to the corresponding classification of source-reservoir-caprock combination, oil source identification and tectonic evolution period study, it is once again confirmed that the deep marine oil and gas multi-phase and diverse accumulation process under the complex structural background of the northern segment of the Western Sichuan Depression can be divided into "primary oil reservoir-primary gas reservoir" and "secondary oil reservoir-primary gas reservoir" types.
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