Xinjiang Petroleum Geology ›› 2024, Vol. 45 ›› Issue (4): 409-416.doi: 10.7657/XJPG20240404

• OIL AND GAS EXPLORATION • Previous Articles     Next Articles

Segmented Structural Characteristics and Growth Mechanism of Transtensional Strike-Slip Fault Zone in Tazhong Uplift

BAI Bingchen1(), WU Guanghui1, MA Bingshan1(), ZHAO Xingxing2a,3,4, TANG Hao1, SHEN Chunguang2b,3,4, WANG Xupeng1   

  1. 1. School of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2. PetroChina Tarim Oilfield Company, a.Oil and Gas Field Productivity Construction Division; b.Research Institute of Exploration and Development, Korla, Xinjiang 841000, China
    3. R&D Center for Ultra-Deep Complex Reservior Exploration and Development, CNPC, Korla, Xinjiang, 841000, China
    4. Xinjiang Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development, Korla, Xinjiang 841000, China
  • Received:2024-03-20 Revised:2024-04-16 Online:2024-08-01 Published:2024-07-23

Abstract:

In the Tarim basin, transpressional strike-slip faults are developed under oblique compression in the Ordovician carbonate rocks, but a series of transtensional strike-slip faults have been discovered in the Tazhong uplift, significantly controlling the hydrocarbon accumulation. Using the 3D seismic data from the western Tazhong uplift, as well as the attributes such as coherence and curvature, the kinematic parameters of the strike-slip faults were statistically analyzed. Through structural analysis of the strike-slip faults, the F21 strike-slip fault zone in the Tazhong uplift was optimally selected for segmented modeling, and its growth mechanism was investigated. The results show that the F21 strike-slip fault zone is segmented horizontally and stratified vertically. Various structural forms such as linear, en echelon, horsetail, wingtip, braided, and overlapping structures are found at the top of the Ordovician carbonates. The characteristics of altitude differences of the fault zone reveal segmentation and tail-end expansion as the growth mechanisms, elucidating its role as a transform fault that regulates the reverse contraction deformation on either side of the strike-slip fault zone, and clarifying its evolution process including stages of en echelon fracturing, growth and linkage, and reactivation.

Key words: Tarim basin, Tazhong uplift, strike-slip fault zone, structural feature, segmentation, modeling, growth mechanism

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