Special Oil & Gas Reservoirs ›› 2024, Vol. 31 ›› Issue (5): 50-58.DOI: 10.3969/j.issn.1006-6535.2024.05.006

• Geologic Exploration • Previous Articles     Next Articles

Depositional Microfacies and Sedimentary Patternsof Sandy Conglomeratein the Carboniferous Bachu Formation of the Tahe Oilfield

Wang Jia'nan1,2,3, Zhao Weiwei1,2, Diao Xindong4, Huo Zhipeng3,5, Gao Jianbo3,5, Li Wenping4, Sun Ningliang3,5, Jiang Dong4*   

  1. 1. Xi′an Shiyou University,Xi′an,Shaanxi 710065,China;
    2. Provincial Key Lab of Hydrocarbon Accumulation Geology,Xi′an,Shaanxi 710065,China;
    3. Northeastern University at Qinhuangdao,Qinhuangdao, Hebei 066004,China;
    4. Sinopec Northwest China Petroleum Bureau,Urumqi,Xinjiang 830011,China;
    5. National Engineering Research Center for Ocean Oil and Gas Exploration,Beijing 100028,China
  • Received:2023-11-24 Revised:2024-06-28 Online:2024-10-25 Published:2024-12-24

Abstract: To address the issues of unclear sedimentary patterns of sandy conglomerate and insufficient research on the depositional microfacies in the Carboniferous Bachu Formation of Tahe Oilfield,the sedimentary patterns,depositionalmicrofacies type and distribution characteristics of the study area are studied by using lithology, drilling,and logging data.The results show that the study area mainly develops three types of rocks:conglomerate,sandstone and mudstone,with a high content of calcareous materials.There are 3 sedimentary facies,5 sedimentary subfacies and 13 sedimentary microfacies in the study area.The sedimentary microfacies vary rapidly in lateral,and multiple phase of the identical sedimentary microfacies are superimposed in vertical.The western part of the study area is delta sedimentary system with braided channels,which interbeds with the tidal flat on its side.A kekule by the Akkulak Uplift, the eastern part is closer to the source area.It develops a fan delta sedimentary system,which interbeds with the tidal flat in the south.The diamicton position of braided channels delta front and tidal flat shows good evidence of oil,gasand water,which is a favorable sedimentary facies belt.The main sedimentary pattern of the study area is the diamicton of braided channel delta front,fan delta front and tidal flat.The findings have guiding significance for the subsequent exploration and development of Tahe Oilfield.

Key words: depositional microfacies, sedimentary pattern, carboniferous sandy conglomerate in the Bachu Formation, Tahe Oilfield

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