›› 2018, Vol. 39 ›› Issue (3): 1-1.doi: 10.7657/XJPG20180301

   

Structure Deformation Characteristics of Wubaiti Area in the Eastern Sichuan Basin

ZHOU Lu1,2,3, ZHANG Xinji2, ZHONG Kexiu4, WU Yong2,5, ZHANG Qiaoyi2, LIU Yi2   

  1. (1.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China; 2.School of Earth Science and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China; 3.Sedimentary and Accumulation Department, PetroChina Key Laboratory of Carbonate Reservoir, Chengdu, Sichuan 610500, China; 4.Chongqing Gas Field, Southwest Oil and Gas Company, PetroChina, Chongqing 400021, China; 5.Sichuan Key Laboratory of Natural Gas Geology, Chengdu, Sichuan 610500, China)
  • Online:2019-01-01 Published:1905-07-16

Abstract: Based on the comprehensive analysis of drilling and logging data and the fine structural interpretation of 3D seismic data of Wubaiti area in the eastern Sichuan basin, the paper establishes a 3D structural model, studies the characteristics of structure deformation in the area by combining with typical seismic interpretation sections, and concludes that the structural deformation in the area is featured with zonation vertically and segmentation in the plane. 5 sets of structural layers are vertically separated by 4 sets of detachment layers. The structure below the Cambrian gypsum-salt bottom is simple with a few fractures in it and is represented by low-amplitude uplift; the structure between the top of the Cambrian gypsum salt layer and the bottom of the Silurian is controlled by the Cambrian gypsum salt layer, in which fault-propagation folds are developed; the structure between the Silurian bottom and the Permian bottom controlled by the Silurian shale detachment layer is represented by anticline; the structure between the Permian bottom and the bottom of 4th member of the Lower Triassic Jialingjiang formation controlled by the Permian coal detachment layer is represented by duplex and anticline; the structure above the bottom of the Upper Triassic Xujiahe formation which is consistent with the main structure and locally controlled by the gypsum-salt layer of the Triassic Jialingjiang formation is represented by wide and gentle anticline. According to the deformation differences among the Cambrian post-salt structures, the deformation can be divided into 3 segments such as southwestern segment, middle segment and northeastern segment in the plane. Combining the deformation degree of each structure with the characteristics of onlap and truncation of the top of the Sinian pre-salt paleo-uplift, it is considered that the pre-salt structure in the northeastern segment has the best oil and gas preserving conditions and can be the favorable target for deep strata exploration

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