Oil & Gas Geology ›› 2024, Vol. 45 ›› Issue (1): 215-230.doi: 10.11743/ogg20240115

• Petroleum Geology • Previous Articles     Next Articles

Recognition of the Carboniferous strata in the Hongche fault zone, Junggar Basin and its hydrocarbon accumulation characteristics

Hong PAN(), Qingsen YU, Xiaoshan LI, Junqiang SONG, Zhibin JIANG, Li WANG, Guanxing LUO, Wenxiu XU, Haoyu YOU   

  1. Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China
  • Received:2023-06-17 Revised:2023-10-27 Online:2024-02-01 Published:2024-02-29

Abstract:

This study focuses on the Carboniferous strata in the Hongche fault zone, Junggar Basin, which are characterized by complex lithology, interior architecture, and stratigraphic contact. To establish the Carboniferous stratigraphic sequence in the fault zone, we conduct a comprehensive analysis under the guidance of the Carboniferous stratigraphic system based on outcrops. This analysis involves examining the lithologic assemblage features, seismic wave group characteristics, and stratigraphic contacts through the fine calibration of lithological properties, electrical properties, and seismic attributes. By comparing the Carboniferous strata in wells with the Carboniferous stratigraphic system based on outcrops in the mountainous area on the northwestern margin of the Junggar Basin, we establish the stratigraphic sequence profiles of the Carboniferous in the fault zone and conduct fine division and correlation of the strata. Additionally, we analyze dominant lithofacies in the Carboniferous strata based on the established Carboniferous stratigraphic framework. Key findings are as follows: (1) Drilling data from the Junggar Basin reveals that the Carboniferous strata in the Hongche fault zone can date back to the Late Carboniferous and consist of the Aladeyikesai (C2a), Hala’alate (C2h), and Chengjisihanshan (C2c) formations top to bottom. These strata demonstrate a westward overlapping and uplifting trend overall, resulting in a tectonic framework characterized by west-east zonation and north-south partition; (2) The C2c is composed of volcanic breccias of explosive facies. In contrast, the C2a and C2h exhibit overlapping and pinchout due to napping. Both formations exhibit decreasing denudation under explosion in the southern part, with the main body primarily presenting volcanic and clastic sedimentary facies; (3) In the Hongche fault zone, the primary oil-bearing pay intervals include the C2c and C2h, with volcanic breccias in the southern part and localized andesitic basalts serving as favorable targets for hydrocarbon exploration.

Key words: fault terrace zone, explosive facies, volcanic sedimentary facies, volcanic breccia, Carboniferous, Hongche fault zone, Junggar Basin

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