新疆石油地质

新疆石油地质 ›› 2018, Vol. 39 ›› Issue (zk(English) ): 1-8.

• •    下一篇

Sedimentation Model and Exploration Significance of Large-Scaled Shallow Retrogradation Fan Delta in Mahu Sag

TANG Yong1, XU Yang2, LI Yazhe2, WANG Libao2   

  1. 1. Research Institute of Exploration and Development, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China;
    2. Hangzhou Institute of Geology, PetroChina, Hangzhou, Zhejiang 310023, China
  • 收稿日期:2017-11-27 修回日期:2017-12-20 出版日期:2019-01-01 发布日期:2021-05-19

Sedimentation Model and Exploration Significance of Large-Scaled Shallow Retrogradation Fan Delta in Mahu Sag

TANG Yong1, XU Yang2, LI Yazhe2, WANG Libao2   

  1. 1. Research Institute of Exploration and Development, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China;
    2. Hangzhou Institute of Geology, PetroChina, Hangzhou, Zhejiang 310023, China
  • Received:2017-11-27 Revised:2017-12-20 Online:2019-01-01 Published:2021-05-19
  • About author:TANG Yong, E-mail: tyong@petrochina.com.cn

PDF

29

摘要： The upper Wuerhe formation of Permian and Triassic Baikouquan formation in Mahu sag and its adjacent areas are a set of near-source coarse deposits under the background of depression basin that are large-scaled shallow retrogradation fan-delta deposits under the background of gentle slope, and 13 lithofacies and 7 sedimentary microfacies are identified based on core observation. Multiple fan deltas are developed on the slope of the sag, and the fan bodies connect with each other. The formation of this kind of large-scaled shallow retrogradation fan delta is closely related to 3 geological conditions. The first is that continuously uplifting periphery ancient mountains and stable river systems provided sufficient provenance for each fan during deposition; the second is that there was a good paleogeographic background such as large basin, shallow water and gentle slope; the third is that continuous lake transgression and multi-stage slope-break are significant conditions for large-sized superposition and merging of sand bodies. A sedimentary model of large-scaled shallow retrogradation fan delta is established, which provides guidance for petroleum prospecting and reserves estimation in Mahu sag.

关键词: Mahu sag, Baikouquan Formation, upper Wuerhe formation, fan delta, sedimentation model, exploration significance

Abstract: The upper Wuerhe formation of Permian and Triassic Baikouquan formation in Mahu sag and its adjacent areas are a set of near-source coarse deposits under the background of depression basin that are large-scaled shallow retrogradation fan-delta deposits under the background of gentle slope, and 13 lithofacies and 7 sedimentary microfacies are identified based on core observation. Multiple fan deltas are developed on the slope of the sag, and the fan bodies connect with each other. The formation of this kind of large-scaled shallow retrogradation fan delta is closely related to 3 geological conditions. The first is that continuously uplifting periphery ancient mountains and stable river systems provided sufficient provenance for each fan during deposition; the second is that there was a good paleogeographic background such as large basin, shallow water and gentle slope; the third is that continuous lake transgression and multi-stage slope-break are significant conditions for large-sized superposition and merging of sand bodies. A sedimentary model of large-scaled shallow retrogradation fan delta is established, which provides guidance for petroleum prospecting and reserves estimation in Mahu sag.

Key words: Mahu sag, Baikouquan Formation, upper Wuerhe formation, fan delta, sedimentation model, exploration significance