Oil & Gas Geology ›› 2020, Vol. 41 ›› Issue (5): 985-995, 1047.doi: 10.11743/ogg20200509

• Petroleum Geology • Previous Articles     Next Articles

Characterization of paleo-topography and karst caves in Ordovician Lianglitage Formation, Halahatang oilfield, Tarim Basin

Chaozhong Ning1(), Suyun Hu1, Wenqing Pan2, Zixiu Yao1, Yong Li1, Wenfang Yuan2   

  1. 1. Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China
    2. Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China
  • Received:2018-02-22 Online:2020-10-28 Published:2020-10-22

Abstract:

The typical eogenetic karsts developed in the Ordovician Lianglitage Formation of the Halahatang area, Tarim Basin, are characterized by the featured paleokarst topography and subsurface paleokarst cave systems.This study initiates from the characterization of the karst terrain on top of the Lianglitage Formation with seismic data and then turns to the analysis of basic features of collapsed karst cave systems by core and thin section observation and log interpretation.In addition, the distribution pattern of the karst cave system is depicted through RMS amplitude and variance attribute fusion; and the factors controlling the development of the karst cave systems are explored against the paleogeological background therein.This study shows that the karst landform on top of the Lianglitage Formation consists of typical elements such as karst highlands, karst ramps, karst troughs and valleys as well as dolines, each with a different distribution pattern.The internal cave systems in the Lianglitage Formation underwent distinctive collapse, filling and compaction, leading to the pathways inside the systems occurring in rectilinear pattern and interweaving into reticular structure.The factors controlling the karst system development include extensive subaerial exposure during the LST period, pre-existing faults and fractures and surficial fluvial systems.

Key words: cave, collapse, karst, paleogeomorphology, Lianglitage Formation, Ordovician, Tarim Basin

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