Oil & Gas Geology ›› 2022, Vol. 43 ›› Issue (1): 79-91.doi: 10.11743/ogg20220107

• Petroleum Geology • Previous Articles     Next Articles

Hydrocarbon accumulation process and exploration direction of the deep Cambrian in Bachu-Tabei area, Tarim Basin

Jianchao Zheng1,2,3(), Bin Li4(), Qian Yuan5, Minghui Qi2,3, Zhongshan Yin2,3, Jun Peng4, Yi Huang2,3, Yeyu Zhang2,3   

  1. 1.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu,Sichuan 610059,China
    2.Sichuan Key Laboratory of Shale Gas Evaluation and Exploitation,Chengdu,Sichuan 610091,China
    3.Technology Innovation Center of Shale Gas Exploration and Development in Complex Structural Areas,MNR,Chengdu,Sichuan 610091,China
    4.School of Geo?science and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China
    5.Exploration & Development Research Institute of Southwest Oil and Gas Field Company,PetroChina,Chengdu,Sichuan 610500,China
  • Received:2020-12-01 Revised:2021-12-01 Online:2022-02-01 Published:2022-01-28
  • Contact: Bin Li E-mail:17783437@qq.com;lbin@swpu.edu.cn

Abstract:

Tarim Basin as a typical marine petroliferous basin, has undergone multi-stage structural transformation, with its Cambrian strata deeply buried, highly risky in exploration. No significant exploration breakthrough has been made in Bachu-Tabei area where two major palaeo-uplifts control hydrocarbon accumulation in the region. In this regard, the study focuses on dynamically revealing the hydrocarbon accumulation process in large area and wide time domain by applying basin modeling technology in combination of the basic data of drilling, seismic exploration and test analysis, with a view to deepening understanding and deciphering exploration direction. The research results suggest that: (1) The thermal evolution of hydrocarbon source rocks in the Yuertus Formation mainly underwent 4 key periods, namely the Middle Caledonian, Late Caledonian-Early Hercynian, Late Hercynian and Late Himalayan periods, in 3 patterns of successive evolution in depression area, relaying evolution in slope area and rapid evolution in peripheral piedmont area; (2) Carrier systems of fault type, carrier bed type and unconformity type are well developed in the study area, indicating favorable conditions for hydrocarbon migration; (3) Three hydrocarbon migration and accumulation modes are put forward, that is, reversed confluence mode as shown by east Bachu area, diffusion mode by west Bachu area and confluence mode by Tabei area; (4) The favorable exploration targets in the eastern part of Bachu area are the structural traps formed and well preserved before the Late Hercynian period, and the structural traps well preserved in the western part. The target zone favorable for hydrocarbon migration in Tabei area is situated inside the platform to the west of Shaya Uplift.

Key words: thermal evolution of source rock, basin modeling, carrier system, hydrocarbon accumulation process, exploration target, Yuertus Formation, Cambrian, Bachu-Tabei area

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