Acta Petrolei Sinica ›› 2023, Vol. 44 ›› Issue (2): 312-328.DOI: 10.7623/syxb202302007

• PETROLEUM EXPIORATION • Previous Articles     Next Articles

Framework and sedimentary model of microbial mound-bank complex in Member 2 of Dengying Formation,Sichuan Basin

Ren Jiaxin1, Song Jinmin1, Liu Shugen1,2, Zhao Rongrong3, Luo Zhong4, Li Zhiwu1, Jin Xin1, Ma Xingzhi4, Li Keran1, Ye Yuehao1, Ding Yi1, Li Wenhao3, Zhao Lingli1, Tian Lizhou1   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Sichuan Chengdu 610059, China;
    2. Xihua University, Sichuan Chengdu 610039, China;
    3. Exploration Division, PetroChina Southwest Oil&Gasfield Company, Sichuan Chengdu 610041, China;
    4. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
  • Received:2021-09-09 Revised:2022-05-27 Online:2023-02-25 Published:2023-03-08

四川盆地灯影组二段微生物丘滩体结构类型与沉积模式

任佳鑫1, 宋金民1, 刘树根1,2, 赵容容3, 罗忠4, 李智武1, 金鑫1, 马行陟4, 李柯然1, 叶玥豪1, 丁一1, 李文皓3, 赵玲丽1, 田立洲1   

  1. 1. 成都理工大学油气藏地质及开发工程国家重点实验室 四川成都 610059;
    2. 西华大学 四川成都 610039;
    3. 中国石油西南油气田公司勘探事业部 四川成都 610041;
    4. 中国石油勘探开发研究院 北京 100083
  • 通讯作者: 宋金民,男,1983年11月生,2012年获中国石油勘探开发研究院博士学位,现为成都理工大学副教授,主要从事油气储层地质的研究和教学工作。Email:songjinmin@sohu.com
  • 作者简介:任佳鑫,男,1997年7月生,2020年获成都理工大学学士学位,现为成都理工大学硕士研究生,主要从事沉积储层研究。Email:1749375404@qq.com
  • 基金资助:
    国家自然科学基金面上项目(No.41872150)和国家自然科学基金企业创新发展联合基金项目(No.U19B6003)资助。

Abstract: Microbial mound-bank complex in Member 2 of Dengying Formation in Sichuan Basin have been a hot spot of geological research and oil-gas exploration in recent years. To characterize the framework and sedimentary model of mound-bank complex in different facies zones, and to better guide oil-gas exploration, the framework of microbial mound-bank complex in Member 2 of Dengying Formation were dissected and their sedimentary model was established using typical section measurement, rock thin section identification, and drone aerial photography modeling. The microbial mound-bank complex in Member 2 of Dengying Formation are dominated by laminated stromatolite dolomite, relict-granule-bearing dolomite, breccia dolomite, thrombolite dolomite, foam spongy dolomite, micrite dolomite and grape-lace shaped dolomite, which can be divided into five microfacies including mound base, mound core, mound flank, mound flat and mound cap. The lithology of mound base is mainly laminated dolomite, that of mound core is mainly stromatolite dolomite, thrombolite dolomite and foam spongy dolomite, that of mound flank is mainly psammitic dolomite and dolorudite, that of mound flat is mainly psammitic dolomite and breccia dolomite, and that of mound cap is mainly laminated dolomite and micrite dolomite. There are 4 types of microbial mound-bank complex developed in slope, platform margin outer zone, platform margin inner zone and intra-platform zone of Sichuan basin, respectively. In the slope, the microbial mound-bank complex are located in the slope facies area, longitudinally shown as the microfacies combination of mound base-mound core-mound cap; in the platform margin outer zone, they are developed in the facies area and in paragenesis with slope deposits in front of the mound, longitudinally shown as the microfacies combination of mound base-mound core-mound flank-mound flat; in the platform margin inner zone, they are located in the facies area and in paragenesis with the lagoon deposits behind the mound, longitudinally shown as the microfacies combination of mound base-mound core-mound flank-mound flat; in the intra-platform zone, they are located in the facies area, in paragenesis with the platform flat and generally shown as the alternate development of mound core and mound flank. In general, different types of microbial mound-bank complex are characterized by "vertically superposed development and continuous horizontal development". Based on the tectonic analysis of different facies zones and different types of microbial mound-bank complex, the paper establishes the sedimentary model of microbial mound-bank complex in intra-platform zone, platform margin inner zone, platform margin outer zone and slope in Member 2 of Dengying Formation, Sichuan Basin. The research and understanding are of great guiding and reference significance for detecting and characterizing high-quality reservoirs in Member 2 of Dengying Formation.

Key words: Sichuan Basin, Member 2 of Dengying Formation, microbial mound-bank complex, mound-bank complex structure, microfacies assemblage, sedimentary model

摘要: 四川盆地灯影组二段(灯二段)微生物丘滩体是近年地质研究和油气勘探的热点,为刻画不同相带丘滩体的结构及沉积模式,以更好指导油气勘探,综合典型剖面实测、岩石薄片鉴定、无人机航拍建模等方法,解剖了灯二段微生物丘滩体的结构,并建立了微生物丘滩体沉积模式。灯二段微生物丘滩体主要发育纹层叠层石白云岩、残余颗粒白云岩、角砾状白云岩、凝块石白云岩、泡沫绵层白云岩、泥晶白云岩和葡萄花边白云岩,可划分出丘基、丘核、丘翼、丘坪和丘盖5种微相。丘基岩性主要为纹层状白云岩,丘核岩性主要为叠层石白云岩、凝块石白云岩和泡沫绵层白云岩,丘翼岩性主要为砂屑砾屑白云岩,丘坪岩性主要为砂屑白云岩和角砾状白云岩,丘盖岩性主要为纹层白云岩和泥晶白云岩。四川盆地发育斜坡型、台缘外带型、台缘内带型和台内型4类微生物丘滩体。斜坡型微生物丘滩体位于斜坡相区,纵向上表现为丘基-丘核-丘盖的微相组合;台缘外带型微生物丘滩体位于台缘外带相区,与丘前斜坡沉积共生,纵向上表现为丘基-丘核-丘翼-丘坪的微相组合;台缘内带型微生物丘滩体位于台缘内带相区,与丘后潟湖沉积共生,纵向上表现为丘基-丘核-丘翼-丘坪的微相组合;台内型微生丘滩体位于台内相区,与台坪共生,整体表现为丘核与丘翼交替发育。整体上,不同类型的微生物丘滩体具有"垂向叠置、平面连续"的发育特征,基于不同相带、不同类型微生物丘滩丘滩体的结构剖析,建立了四川盆地灯二段台内-台缘内带-台缘外带-斜坡的微生物丘滩体沉积模式。研究认识对于寻找并刻画灯二段优质储层具有重要指导与借鉴意义。

关键词: 四川盆地, 灯影组二段, 微生物丘滩体, 丘滩体结构, 微相组合, 沉积模式

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