Earth Science Frontiers ›› 2025, Vol. 32 ›› Issue (4): 453-470.DOI: 10.13745/j.esf.sf.2025.2.1

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Structural analysis and reservoir-controlling significance of No.19 strike-slip fault in the eastern Aman transition zone, Tarim Basin

LIU Binglei1,2(), ZHAO Yonggang1,2,*(), ZHANG Yintao3, ZHOU Fei3, XIE Zhou3, YAO Chao3, YIN Shuai1,2, DING Liuyang1,2, ZHAO Longfei3, SUN Chong3   

  1. 1. School of Earth Science and Engineering, Xi’an Shiyou University, Xi’an, 710065, China
    2. Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi’an Shiyou University, Xi’an, 710065, China
    3. Research Institute of Exploration and Development, Tarim Oilfield Company, Petro China, Korla, 841000, China
  • Received:2024-12-27 Revised:2025-02-14 Online:2025-07-25 Published:2025-08-04

Abstract:

Strike-slip faults are well developed in the northern depression of the Tarim Basin, playing a crucial role in controlling the development of fault-controlled reservoirs in the Ordovician carbonate rocks in the eastern Aman Transition Zone. Based on 3D seismic data and Ordovician geological information, and from the perspective of reservoir characterization and development needs of the No.19 strike-slip fault-controlled oil reservoir, this study conducts a detailed analysis of the layered deformation characteristics, segmented deformation features, activity patterns, evolutionary stages, and fault evolution process of the No.19 strike-slip fault zone, with particular emphasis on its reservoir-controlling significance. The main findings are as follows: (1) The No.19 strike-slip fault zone can be divided into four structural layers from bottom to top: the subsalt Cambrian structural layer, Middle Cambrian evaporite structural layer, Middle-Lower Ordovician carbonate structural layer, and Silurian clastic structural layer. (2) Based on fault strike and combination characteristics of faults at the top of Ordovician carbonate rocks, the fault zone is classified into horsetail, en echelon, braided, overlapping, and linear segments. (3) The Middle-Lower Ordovician section of the No.19 strike-slip fault zone exhibits strong overall activity with significant deformation, and can be subdivided into seven transtensional segments, seven transpressional segments, and three translational segments. The fault zone underwent multistage tectonic evolution, with the Early and Middle Caledonian being the key active periods. (4) Different planar segmentation patterns exert varying controls on reservoir development: braided and overlapping segments show relatively better reservoir development, while horsetail, en echelon, and linear segments exhibit poorer reservoir development. Profile structural styles significantly influence reservoir development, with transtensional segments favoring large-scale reservoir formation, transpressional segments promoting reservoir development, and translational segments yielding limited reservoir scale. The superposition of planar segmentation patterns and profile structural styles leads to notable differences in hydrocarbon accumulation scale across different superimposed segments of the same fault zone. (5) The layered deformation, planar segmentation patterns, activity characteristics, and profile structural styles collectively contribute to variations in reservoir development along different sections of the same fault zone. Research significance: This study provides an important structural foundation for investigating the vertical development patterns and connectivity of strike-slip fault-controlled reservoirs, and offers valuable insights for further research on the reservoir-controlling significance of strike-slip fault-controlled reservoirs.

Key words: eastern Aman Transition Zone, strike-slip fault, Ordovician, planar segmentation pattern, profile structural style, superimposed reservoir control

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