古地理学报 ›› 2020, Vol. 22 ›› Issue (3): 504-522. doi: 10.7605/gdlxb.2020.03.035

• 岩相古地理学及沉积学 • 上一篇    下一篇

四川盆地下寒武统龙王庙组浅水碳酸盐岩台地沉积相特征及模式*

刘自亮1,2, 邓昆1,2, 施泽进1, 田亚铭3, 王勇3, 沈芳1, 谭谦1, 龚晓星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 成都理工大学能源学院,四川成都 610059;
    3 成都理工大学地球科学学院,四川成都 610059
  • 收稿日期:2020-03-07 修回日期:2020-04-05 出版日期:2020-06-01 发布日期:2020-06-06
  • 作者简介:刘自亮,男,1978年生,成都理工大学能源学院副教授,从事沉积学和储层地质学教学和科研工作。E-mail: bugliu2001@163.com。
  • 基金资助:
    * 国家重点研发计划专项(编号: 2018YFC0604201)和油气藏地质及开发工程国家重点实验室(成都理工大学)开放基金(编号: PLC201901013)联合资助

Sedimentary facies and model of shallow water carbonates platform of the Lower Cambrian Longwangmiao Formation in Sichuan Basin

Liu Zi-Liang1,2, Deng Kun1,2, Shi Ze-Jin1, Tian Ya-Ming3, Wang Yong3, Shen Fang1, Tan Qian1, Gong Xiao-Xing1   

  1. 1 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;
    2 School of Energy Resources,Chengdu University of Technology,Chengdu 610059,China;
    3 School of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China
  • Received:2020-03-07 Revised:2020-04-05 Online:2020-06-01 Published:2020-06-06
  • About author:About the first author Liu Zi-Liang,born in 1978,is an associate professor of Chengdu University of Technology. He is mainly engaged in sedimentology and reservoir geology. E-mail: bugliu2001@163.com.
  • Supported by:
    Co-funded by National Key Research and Development Program of China(No.2018YFC0604201),and the Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology)(No. PLC201901013)

摘要: 准确建立四川盆地龙王庙组沉积模式和精细刻画颗粒滩时空分布规律,是提高天然气勘探成功率的关键。依据野外露头、钻井、测井和地震等资料,综合分析四川盆地及周缘下寒武统龙王庙组沉积相类型及特征;以四级层序为单元,精细刻画等时地层格架内沉积相时空展布特征,建立沉积模式,揭示颗粒滩发育规律,指出下一步天然气勘探方向。结果表明: (1)四川盆地及周缘龙王庙组发育典型浅水碳酸盐岩镶边台地沉积体系,自盆地西缘向东依次发育混积潮坪、局限台地(颗粒滩、云坪和咸化潟湖等微相类型)、开阔台地(颗粒滩、灰坪等微相类型)、台地边缘和斜坡—盆地等沉积相类型;(2)建立了“一凹两隆,双滩成带”的沉积模式,颗粒滩的发育主要受控于古地貌和相对海平面升降,具体表现为垂向上主要发育于四级层序海退时期,平面上沿台地边缘带和围绕咸化潟湖的相对隆起区呈带状分布。由于颗粒滩是优质储集层发育的有利相带,因此该结果可为四川盆地寒武系龙王庙组下一步天然气勘探提供沉积地质基础。

关键词: 四川盆地, 寒武系, 龙王庙组, 沉积相, 颗粒滩

Abstract: Building the sedimentary model accurately and delineating the spatial-temporal distribution of grain bank are the keys to increase the rate of success in natural gas exploration. Thus,the types and characteristics of sedimentary facies of the Longwangmiao Formation in the Sichuan Basin were studied based on field outcrops,drilling,logging and seismic data. Taking a fourth-order sequence systems tract as a unit,the spatial-temporal distribution characteristics of sedimentary facies within the chronostratigraphic framework were precisely described,and the depositional model of the Longwangmiao Formation was established to reveal the development mechanisms of grain bank and point out the future natural gas exploration. The results showed that: (1)The typical shallow carbonate platform depositional system was developed in the Longwangmiao Formation of the Sichuan Basin and its surrounding areas. Mixed tidal flat,restricted platform(microfacies types including grain bank,dolomitic tidal flat,lagoon,and gypsum lagoon),open platform(microfacies types including grain bank,lime tidal flat),platform margin,and slope-basin were developed from the edge to the interior of the basin;(2)A sedimentary model was established,which was characterized by “one depression,two uplifts,and two grain banks in the form of belts”. The development of grain banks was mainly controlled by palaeo-topography and relative sea-level fluctuation. It was mainly developed in the highstand systems tract of a fourth-order sequence vertically,and distributed as a belt along the platform margin and around the lagoon area horizontally. Our paper pointed out the grain shoal deposits are the material basis for the development of high-quality reservoirs,the results thus provide a sedimentary geological basis for future natural gas exploration of the Cambrian Longwangmiao Formation in the Sichuan Basin.

Key words: Sichuan Basin, Cambrian, Longwangmiao Formation, sedimentary facies, grain bank

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