古地理学报 ›› 2024, Vol. 26 ›› Issue (4): 779-795. doi: 10.7605/gdlxb.2024.04.051

• 层序地层学及古地理学 • 上一篇    下一篇

鄂尔多斯盆地庆城油田延长组页岩层系层序地层与沉积相特征*

刘明成1,2, 吴胜和1,2, 万晓龙1,2,4, 李桢3, 樊建民3, 陈朝晖1,2, 王梓沣1,2, 刘海旭1,2   

  1. 1 油气资源与工程全国重点实验室,中国石油大学(北京),北京 102249;
    2 中国石油大学(北京)地球科学学院,北京 102249;
    3 中国石油长庆油田分公司勘探开发研究院,陕西西安 710018;
    4 中国石油长庆油田分公司第十一采油厂,甘肃庆阳 745000
  • 收稿日期:2023-07-15 修回日期:2023-09-16 出版日期:2024-08-01 发布日期:2024-07-29
  • 通讯作者: 吴胜和,男,1963年生,中国石油大学(北京)教授、博士生导师,主要从事沉积古地理、储层表征与建模研究。E-mail: reser@cup.edu.cn
  • 作者简介:刘明成,男,1996年生,中国石油大学(北京)博士研究生,主要从事沉积学、储层表征与建模研究。E-mail: cupliumingcheng@163.com。
  • 基金资助:
    *中石油与中国石油大学(北京)战略合作课题(编号: ZLZX2020-02)以及国家自然科学基金(编号: 42272110)联合资助

Sequence stratigraphy and sedimentary facies characteristics of the shale strata of Yanchang Formation in Qingcheng Oilfield,Ordos Basin

LIU Mingcheng1,2, WU Shenghe1,2, WAN Xiaolong1,2,4, LI Zhen3, FAN Jianmin3, CHEN Zhaohui1,2, WANG Zifeng1,2, LIU Haixu1,2   

  1. 1 National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;
    2 College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;
    3 Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company, Xi'an 710018, China;
    4 The 11th Oil Production Plant,PetroChina Changqing Oilfield Company,Gansu Qingyang 745000,China
  • Received:2023-07-15 Revised:2023-09-16 Online:2024-08-01 Published:2024-07-29
  • Contact: WU Shenghe,born in 1963,is a professor and Ph.D. supervisor of China University of Petroleum(Beijing). He is mainly engaged in sedimentary palaeogeography,reservoir characterization and modelling. E-mail: reser@cup.edu.cn.
  • About author:LIU Mingcheng,born in 1996,is a Ph.D. candidate of China University of Petroleum(Beijing). He is mainly engaged in sedimentology palaeogeography,reservoir characterization and modeling research. E-mail: cupliumingcheng@163.com.
  • Supported by:
    Co-funded by the Strategic Cooperation Technology Projects of CNPC and CUPB(No. ZLZX2020-02),and the National Natural Science Foundation of China(No.42272110)

摘要: 鄂尔多斯盆地三叠系延长组页岩层系蕴藏着丰富的油气资源,但其层序格架及沉积相展布存在较大的争议,从而影响着页岩油气的精细勘探与开发。以庆城油田西233区块为例,应用岩心、测井及最新的三维地震资料重构了层序地层格架及沉积相分布。研究表明,在延长组原长81—长32砂组内,地层向湖盆中心呈进积叠置样式,可分为2个长期基准面旋回和10个中期基准面旋回。在每个中期旋回内,向盆地方向的古地貌依次为浅水带、斜坡带和盆底带。浅水带主要发育三角洲; 斜坡带发育重力流水道,顺斜坡呈窄条带状分布; 在盆底带近端发育重力流朵叶体沉积,砂体夹于泥页岩中,而盆底带远端主要为深湖页岩夹滑塌体沉积。原长7油层组页岩层系为1套穿时地层,由多个中期旋回的斜坡带下部、盆底带湖底扇砂体和半深湖—深湖泥岩组成。这一研究不仅对鄂尔多斯盆地夹层型页岩油的有效开发(开发区优选及水平井部署)具有重要的指导作用,亦对拗陷湖盆层序与沉积演化理论的发展具有一定的促进作用。

关键词: 鄂尔多斯盆地, 延长组, 7油层组, 湖底扇, 页岩层系, 层序地层格架, 沉积相

Abstract: The shale succession of Yanchang Formation in Ordos Basin is rich in hydrocarbon resources,but its sequence framework and sedimentary facies distribution are controversial,which affects the exploration and development of shale hydrocarbon. Taking the Xi233 area of Qingcheng Oilfield as an example,this paper reconstructs the sequence stratigraphic framework and sedimentary facies distribution using core,logging,and the latest 3D seismic data. Research has shown that in the original Chang 81-Chang 32 interval of the Yanchang Formation,the strata represent a progradational superposition pattern towards the center of the lake basin,which can be divided into two long-term base-level cycles and ten mid-term base level cycles. In each mid-term cycle,the paleogeomorphology towards the basin is followed by shallow-water area,slope area and basin floor area. The shallow-water area mainly develops deltas. The slope belt develops gravity flow channels,which are distributed in narrow bands along the slope; the gravity flow lobe deposits are developed in the proximal basin floor,and the sand bodies are sandwiched in mud shale. The distal basin floor is mainly deep-lake shale interbedded with slump deposits. The original “Chang 7 interval” shale strata is a set of diachronous strata,which is composed of sublacustrine fan sand bodies and semi-deep to deep lake shale in the lower part of the slope belt and basin floor belt of multiple mid-cycles. This study not only plays an important guiding role in the effective development of interbedded shale oil in the Ordos Basin(optimization of development areas and deployment of horizontal wells),but also promotes the development of the theory of sequence and sedimentary evolution in depression lake basins.

Key words: Ordos Basin, Yanchang Formation, Chang 7 interval, sublacustrine fan, shale strata, sequence stratigraphic framework, sedimentary facies

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