Oil & Gas Geology ›› 2024, Vol. 45 ›› Issue (5): 1211-1225.doi: 10.11743/ogg20240502

• Petroleum Geology • Previous Articles     Next Articles

Advances in research on the genetic mechanisms of intracratonic strike-slip fault system and their control on hydrocarbon accumulation: A case study of the northern Tarim Basin

Shang DENG1,2(), Huabiao QIU1(), Dawei LIU1, Jun HAN2, Zhixing RU1, Weilong PENG1, Qing BIAN1, Cheng HUANG2   

  1. 1.Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 102206, China
    2.Northwest Oil Field Company, SINOPEC, Urumqi, Xinjiang 830011, China
  • Received:2024-03-23 Revised:2024-06-20 Online:2024-10-30 Published:2024-11-06
  • Contact: Huabiao QIU E-mail:dengshang.syky@sinopec.com;qiuhuabiao.syky@sinopec.com

Abstract:

In recent years, strike-slip fault system over large areas has been identified in multiple cratonic basins in China, representing a significant structural style in interior cratonic basins. With the strike-slip fault system in the northern Tarim Basin in mind, we apply techniques like seismic-geological analysis of the faulted structure, discrete element numerical simulation of the fault dynamic evolution, finite element numerical simulation of off-fault deformations, and structural analysis of the fault cores and associated damage zones (also referred to as the fault core-damage zone architectures) to study. In combination with well production data, new understandings on the origin of the strike-slip fault system and its control on hydrocarbon accumulation are proposed. The results are as follows. (1) The strike-slip fault system in the northern Tarim Basin is formed as a result of northward thrusting of large thrust belts to accommodate regional shortening under the non-coaxial extrusion in the central Tarim Basin, featuring a dynamic genetic mechanism of non-coaxial extrusion and accommodation of regional deformations. (2) With increasing strike-slip fault displacement, the crackle and mosaic breccias in the fault cores gradually evolve into chaotic breccias and cataclasites. The resulted breccias of high evolutionary degree can reduce the fault core-damage zone permeability. (3) The pressure-ridge structures along the strike-slip faults formed under intense strike-slip transpressional stress, is characterized by extension in the upper part and compression in the lower part, resulting in the fault-controlled reservoirs in large scale primarily occurring at depths. (4) The decoupling of the gypsum-salt layer with the overlying strata related to the strike-slip faulting plays an important role in controlling the vertical hydrocarbon migration. (5) Layered deformation, as an inherent characteristic of the strike-slip faults with small displacement at great deeps, governs the vertical migration and accumulation of hydrocarbons in multiple layers along the strike-slip faults.

Key words: layered deformation, fault core-damage zone structure, hydrocarbon reservoir- and accumulation-governing characteristics, genetic mechanism, intracratonic strike-slip fault, Tarim Basin

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