西南石油大学学报(自然科学版) ›› 2020, Vol. 42 ›› Issue (5): 13-24.DOI: 10.11885/j.issn.1674-5086.2019.03.04.03

• GEOLOGY EXPLORATION • Previous Articles     Next Articles

Sedimentary Facies Distribution and Exploration Significance of the Middle Permian Qixia Formation in the Sichuan Basin

BAI Xiaoliang1,2, YANG Yueming1, WEN Long1, LUO Bing1, HONG Haitao1   

  1. 1. Research Institute of Petroleum Exploration and Development, Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610051, China;
    2. School of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2019-03-04 Online:2020-10-10 Published:2020-10-10

Abstract: Through analysis of the seismic and logging data, we established standard lithology and Paleozoic stratigraphic profiles, and identified facies markers. Sedimentary facies were divided into the open platform facies, platform margin facies, slope facies, and basin facies. The slope facies and the basin facies were identified in the Pingwu-Maowen-Xiaojin area. A zone of platform margin facies had developed in the Western Sichuan Area. The Western Sichuan-Central Sichuan uplift is a developmental belt of the intra-platform beach subfacies of the open platform facies. The Northern Sichuan-Southern Shu low uplift is the open-sea and intra-platform beach subfacies of the open platform facies. The Eastern-Sichuan area is the intra-platform shallow-swamp subfacies of the open platform facies. Regional stratigraphic correlation and the distribution of sedimentary facies indicate that the pre-Permian sedimentary paleo-geomorphology controlled the sedimentary pattern of the Qixia Formation, while the development of the Caledonian uplift and the Western Sichuan rift Basin jointly controlled the distribution of the platform margin facies of the Qixia Formation in Western Sichuan. The platform margin facies belt of the Qixia Formation developed a facies-controlled dolomite reservoir, which formed a good source-storage match with the lower Cambrian high-quality hydrocarbon source layer. The platform margin facies belt of the Qixia Formation is a key exploration area for deep marine carbonate rocks. The Devonian-Permian has the same source-storage matching relationship, providing geological conditions for the development of large-scale tectonic-lithologic trap gas reservoirs. The large-scale concealed structural highs developed in the lower part of the nappe, which is an important zone favorable for overall exploration and three-dimensional exploration.

Key words: Sichuan Basin, Middle Permian, Qixia Formation, sedimentary facies, Caledonian uplift, Western Sichuan rift basin, platform margin

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