石油学报 ›› 2020, Vol. 41 ›› Issue (6): 643-657.DOI: 10.7623/syxb202006001

• 地质勘探 •    下一篇

歧口凹陷歧北次凹沙河街组三段页岩油地质特征与勘探突破

赵贤正, 周立宏, 蒲秀刚, 时战楠, 韩国猛, 吴佳朋, 韩文中, 张伟, 高欢欢, 马建英, 汪虎   

  1. 中国石油大港油田公司 天津 300280
  • 收稿日期:2020-03-10 修回日期:2020-05-20 出版日期:2020-06-25 发布日期:2020-07-11
  • 通讯作者: 赵贤正,男,1962年10月生,1986年获华东石油学院学士学位,2005年获中国石油大学(北京)博士学位,现为中国石油大港油田公司总经理、教授级高级工程师、李四光地质科学奖及孙越崎能源大奖获得者,主要从事油气勘探与开发研究和管理工作。
  • 作者简介:赵贤正,男,1962年10月生,1986年获华东石油学院学士学位,2005年获中国石油大学(北京)博士学位,现为中国石油大港油田公司总经理、教授级高级工程师、李四光地质科学奖及孙越崎能源大奖获得者,主要从事油气勘探与开发研究和管理工作。Email:xzzhao@petrochina.com.cn
  • 基金资助:

    中国石油天然气股份有限公司科技重大专项"大港油区效益增储稳产关键技术研究与应用"(2018E-11)资助。

Geological characteristics and exploration breakthrough of shale oil in Member 3 of Shahejie Formation of Q ibei subsag, Q ikou sag

Zhao Xianzheng, Zhou Lihong, Pu Xiugang, Shi Zhannan, Han Guomeng, Wu Jiapeng, Han Wenzhong, Zhang Wei, Gao Huanhuan, Ma Jianying, Wang Hu   

  1. PetroChina Dagang Oilfield Company, Tianjin 300280, China
  • Received:2020-03-10 Revised:2020-05-20 Online:2020-06-25 Published:2020-07-11

摘要:

歧口凹陷歧北次凹沙河街组三段(沙三段)湖泛期细粒沉积发育、烃源岩品质好、页岩油资源丰富,但其研究尚处于起步阶段,在沧东凹陷孔店组二段湖相页岩油工业化开发的带动下,落实其勘探前景势成必然。为探究歧北次凹沙三段页岩油的地质特征及勘探潜力,依据F39X1井、QY10-1-1井等多口井的岩心、分析化验、测井资料和录井资料,对沙三段页岩层系的地质特征、页岩油类型与富集模式、甜点的空间分布规律等开展了综合研究。歧北次凹沙三段的矿物组成和岩石类型多样,主要包括灰质白云质页岩、长英质页岩、混合质页岩及微晶白云岩、亮晶生屑白云岩、粉砂岩等;烃源岩的总有机碳(TOC)含量主要分布在1%~3%,以Ⅱ型干酪根为主且指示热演化成熟度的镜质体反射率(Ro)普遍高于0.7%;储集空间主要包括粒间孔、晶间孔、生物体腔孔、有机孔及层理缝、构造(微)缝等;页岩油的超越效应明显(油饱和度指数平均为116.3 mg/g)、荧光显示良好。在歧北次凹沙三段中识别出单一型和夹层型2类页岩油,构建了高TOC滞留型页岩油和低TOC运移型页岩油2种富集模式,并建立了基于油饱和度指数、TOC和脆性指数等多参数的甜点定量评价方法及标准。针对甜点区部署了QY10-1-1水平井,其初期的折算产油量达103.5 t/d,预计可形成亿吨级增储新领域。勘探发现证实歧口凹陷的沙三段细粒岩段具备良好的页岩油勘探潜力。

关键词: 陆相页岩油, 页岩层系, 沙河街组三段, 歧北次凹, 歧口凹陷

Abstract:

Lacustrine fine-grained sediments are developed in Member 3 of Shahejie Formation of Qibei subsag of Qikou sag, with good source rock quality and rich in shale oil resources. However, the corresponding research is still in the early stage. As stimulated by the industrial development of lacustrine shale oil in Member 2 of Kongdian Formation of Cangdong sag, it is inevitable to implement the exploration prospects of fine-grained sediments. In order to explore the geological characteristics and exploration potential of shale oil in Member 3 of Shahejie Formation of Qibei subsag, based on the cores, analytical tests, logging data and logging data of the wells such as F39X1 and QY10-1-1, a comprehensive study is carried out on the geological characteristics, shale oil types and enrichment patterns of the shale strata in Member 3 of Shahejie Formation, and the spatial distribution of sweet spots. There are various mineral compositions and rock types in Member 3 of Shahejie Formation of Qibei subsag, mainly including calcareous-dolomitic shale, felsic shale, hybrid shale, micritic dolomite, sparry bioclastic dolomite, and siltstone. The total organic carbon (TOC) content of source rocks is mainly distributed between 1% and 3%, dominated by type Ⅱ kerogen, and the vitrinite reflectance (Ro) is generally higher than 0.7%. The reservoir spaces mainly include intergranular pores, intercrystalline pores, biological cavity pores, organic pores, bedding fractures, and structural (or microstructural) fractures. The shale oil presents obvious crossover effect (with an average oil saturation index of 116.3 mg/g), as well as good fluorescence effect. This study identifies two types of shale oil, i.e., monolayer type and interbedded type, in Member 3 of Shahejie Formation in Qibei subsag, constructs two enrichment patterns, i.e., high-TOC retention-type and low-TOC migration-type shale oil, and establishes the quantitative evaluation methods and standards of sweet spot based on multiple parameters such as oil saturation index, TOC and brittleness index. For the horizontal well QY10-1-1 deployed in the sweet spot, the initial oil production is calculated to be 103.5 t/d; it is expected to form a new field with the increasing reserves of 100 million tons. It is confirmed by the exploration discovery that the fine-grained rock section of Member 3 of Shahejie Formation in Qikou sag has good exploration potential for shale oil.

Key words: terrestrial shale oil, shale strata, Member 3 of the Shahejie Formation, Qibei subsag, Qikou sag

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