石油学报 ›› 2022, Vol. 43 ›› Issue (11): 1509-1519.DOI: 10.7623/syxb202211001

• 地质勘探 •    下一篇

鄂尔多斯盆地延长组7段3亚段页岩型页岩油储层特征及勘探方向

李士祥1, 郭芪恒1,2, 周新平1, 刘元博3, 刘江艳1   

  1. 1. 中国石油长庆油田公司勘探开发研究院 陕西西安 710018;
    2. 中国石油大学(北京)地球科学学院 北京 102249;
    3. 中国石油长庆油田公司第一采油厂 陕西延安 716000
  • 收稿日期:2022-06-28 修回日期:2022-07-07 出版日期:2022-11-25 发布日期:2022-12-02
  • 通讯作者: 郭芪恒,男,1994年2月生,2020年获中国石油大学(北京)硕士学位,现为中国石油大学(北京)地质工程专业博士研究生,主要从事页岩油勘探开发及综合研究工作。Email:guoqh_cq@petrochina.com.cn
  • 作者简介:李士祥,男,1981年6月生,2017年获成都理工大学博士学位,现为中国石油长庆油田公司教授级高级工程师,主要从事页岩油勘探开发及综合研究工作。Email:sxlee1981_cq@petrochina.com.cn
  • 基金资助:
    中国石油天然气集团有限公司前瞻性基础性研究重大科技项目"鄂尔多斯盆地页岩油勘探开发理论与关键技术研究"(2021DJ1806)和国家重点基础研究发展计划(973)项目"淡水湖盆细粒沉积与富有机质页岩形成机理"(2014CB239003)资助。

Reservoir characteristics and exploration direction of pure shale-type shale oil in the 3rd sub-member, 7th Member of Yanchang Formation in Ordos Basin

Li Shixiang1, Guo Qiheng1,2, Zhou Xinping1, Liu Yuanbo3, Liu Jiangyan1   

  1. 1. Research Institute of Exploration and Development, PetroChina Changqing Oilfield Company, Shaanxi Xi'an 710018, China;
    2. College of Geosciences, China University of Petroleum, Beijing 102249, China;
    3. No. 1 Oil Production Plant, PetroChina Changqing Oilfield Company, Shaanxi Yan'an 716000, China
  • Received:2022-06-28 Revised:2022-07-07 Online:2022-11-25 Published:2022-12-02

摘要: 鄂尔多斯盆地三叠系延长组7段(长7段)泥页岩发育,针对其内部富集的页岩型页岩油尚未取得勘探进展,仅在少量直井的试油阶段突破出油关,但试采效果整体较差。系统梳理了长7段3亚段(长73亚段)泥页岩的岩石学、地球化学和储层特征,优选页岩型页岩油的富集有利参数,明确了其成藏条件、勘探方向及潜力。相较于暗色泥岩,长73亚段的黑色页岩表现为多类型纹层频繁发育、有机质丰度高、生油母质类型好、主生烃期早、含油率高的特征,是页岩型页岩油勘探的有利岩性。受水平页理缝和陆源长英质、凝灰质等相对高孔高渗纹层的复合影响,黑色页岩的水平渗透率普遍高于垂直渗透率。长73亚段泥页岩的储集空间以刚性矿物支撑的粒间孔、粒内溶蚀孔、黏土矿物晶间孔及黄铁矿晶间孔为主,页理缝和超压微裂缝较发育。"有机质+陆源长英质纹层"、"有机质+凝灰质纹层"二元纹层组合与页理缝构成的复合单元对页岩油赋存最为有利。总有机碳(TOC)含量为4%~14%、镜质体反射率Ro>0.8%、页理及纹层发育、脆性矿物含量高的长英质黑色页岩是长73亚段页岩型页岩油的有利勘探目标,黑色页岩厚度相对较大、有机质丰度适中的马岭—华池深洼区是页岩型页岩油勘探的Ⅰ类有利区。鄂尔多斯盆地长73亚段页岩型页岩油资源丰富,有望成为盆地非常规石油勘探开发的现实性重大战略接替新领域。

关键词: 鄂尔多斯盆地, 页岩型, 页岩油, 长73亚段, 勘探潜力

Abstract: Mudstone and shale are developed in 7th Member of the Triassic Yanchang Formation in Ordos Basin, and there is no progress in the exploration of pure shale-type shale oil enriched inside. Oil has been produced only from a few vertical wells in the well testing stage, and the overall pilot production effect is poor. The paper systematically summarizes the petrological, geochemical and reservoir characteristics of mud shale in the 3rd sub-member of 7th Member of Yanchang Formation (Chang 73 sub-member), optimizes the favorable parameters for the enrichment of shale type shale oil, and determines its hydrocarbon accumulation conditions, exploration direction and potential. Compared with dark mudstone, the black shale in Chang 73 sub-member is characterized by frequent development of multi-type laminae, high abundance of organic matters, good type of parent material of source rock, early main hydrocarbon generation stage and high oil content, which are favorable lithologies for the exploration of pure shale-type shale oil. The horizontal permeability of black shale is generally higher than its vertical permeability due to the complex effect of horizontal lamellation fractures and high porosity and high permeability laminae such as terrigenous felsic and tuffaceous sandstone. The reservoir space of mud shale in Chang 73 sub-member is mainly composed of intergranular pores, intragranular denudation pores, clay mineral intercrystalline pores and pyrite intercrystalline pores supported by rigid minerals; lamellation fractures and overpressure microfractures are developed. The composite element composed of the binary laminae combination of "organic matters+terrigenous felsic lamina" and "organic matters + tuffaceous lamina" and lamellation fractures is the most favorable for the occurrence of shale oil. Black felsic shale with the total organic carbon (TOC) content of 4 % ~14 % , vitrinite reflectance Ro>0.8 % , development of lamellation and laminae as well as high content of brittle minerals is a favorable exploration target for pure-shale type shale oil in Chang 73 sub-member. The Maling-Huachi deep depression area with thick black shale and moderate organic matter abundance is a Class I favorable area for exploration of pure shale-type shale oil. The Chang 73 sub-member in Ordos Basin is rich in pure-shale type shale oil resources, which is expected to actually become a new major strategic replacement area for unconventional oil exploration and development in the basin.

Key words: Ordos Basin, shale-type, shale oil, 3rd sub-member, 7th Member of Yanchang Formation, exploration potential

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