特种油气藏 ›› 2024, Vol. 32 ›› Issue (5): 76-84.DOI: 10.3969/j.issn.1006-6535.2025.05.009

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玛湖凹陷风城组成岩作用及其对物性的影响

张路路1,2, 杨智3, 高之业1,2, 张洪3, 马国明1,2, 贾荔丹1,2, 刘昭臣1,2, 信昊天1,2   

  1. 1.油气资源与工程全国重点实验室,北京 102249;
    2.中国石油大学(北京),北京 102249;
    3.中国石油勘探开发研究院,北京 100083
  • 收稿日期:2024-09-24 修回日期:2025-07-16 出版日期:2025-09-25 发布日期:2025-10-30
  • 通讯作者: 杨智(1980—),男,教授级高级工程师,博士生导师,2004年毕业于中国地质大学(武汉)资源勘查工程专业,2009年毕业于该校矿产普查与勘探专业,获博士学位,现主要从事非常规油气地质、常规油气风险勘探等工作。
  • 作者简介:张路路(2001—),女,2023年毕业于中国石油大学(北京)勘查技术与工程专业,现为该校地质资源与地质工程专业在读硕士研究生,主要从事非常规油气地质研究工作。
  • 基金资助:
    国家能源致密油气研发中心开放基金“页岩油储层‘甜点’孔缝结构和烃类赋存多尺度评价方法研发”(2023-KFKT-12);中国石油天然气集团有限公司-中国石油大学(北京)战略合作科技专项“玛湖凹陷风城组页岩油富集机理及评价关键技术研究”(ZLZX2020-01-05)

Diagenesis of the Fengcheng Formation in the Mahu Sag and its impact on physical properties

ZHANG Lulu1,2, YANG Zhi3, GAO Zhiye1,2, ZHANG Hong3, MA Guoming1,2, JIA Lidan1,2, LIU Zhaochen1,2, XIN Haotian1,2   

  1. 1. State Key Laboratory of Oil and Gas Resources and Engineering,Beijing 102249, China;
    2. China University of Petroleum (Beijing),Beijing 102249, China;
    3. China Petroleum Exploration and Production Research Institute,Beijing 100083, China
  • Received:2024-09-24 Revised:2025-07-16 Online:2025-09-25 Published:2025-10-30

摘要: 准噶尔盆地玛湖凹陷二叠系风城组岩相复杂,成岩作用类型多样,其储集能力受成岩作用影响显著,然而不同岩相成岩作用差异性及演化序列不明,对储集能力控制作用不清,制约了对风城组成储机理的深入认识。为此,通过图像处理技术分析岩石光学薄片与扫描电镜图像,定量识别矿物与孔缝特征,明确了成岩作用类型及其演化序列,结合岩心描述、高压压汞实验等,系统分析了成岩作用对页岩油储层储集能力的影响机制。研究结果表明:风城组页岩油储层岩相可划分为3类,Ⅰ型粉砂岩相孔隙度与渗透率最高,储集能力强,Ⅱ型碳酸盐岩相次之,Ⅲ型泥页岩相最低。3类岩相具有相似的成岩演化序列,但主导成岩作用不同。风城组储层处于中成岩B期,其成岩演化序列为早期机械压实、方解石与白云石胶结、黄铁矿化、早期油气充注、溶蚀作用、破裂作用、晚期油气充注及溶蚀作用等。压实和碳酸盐岩胶结为造成储层致密化的主要因素,而溶蚀及破裂作用是致密储层成岩改造的关键,对储集空间的形成和改善具有一定的贡献。研究成果对深化风城组页岩油储层成储机制、完善页岩油储层评价体系以及“甜点”优选具有重要的指导意义。

关键词: 成岩作用, 储层物性, 成岩演化, 玛湖凹陷, “甜点”, 风城组

Abstract: The lithofacies of the Permian Fengcheng Formation in the Mahu Sag,Junggar Basin are complex,and the types of diagenesis are diverse.Its reservoir capacity is significantly affected by diagenesis.However,the differences in diagenesis among different lithofacies and their evolutionary sequences are unclear,and the controlling effects on reservoir capacity are not well understood,hindering an in-depth understanding of the reservoir formation mechanism of the Fengcheng Formation.In response to this issue,through image processing technology to analyze rock optical thin sections and scanning electron microscope (SEM) images,minerals and pore-fracture characteristics were quantitatively identified,the types of diagenesis and their evolutionary sequences were clarified,and the impact mechanisms of diagenesis on the reservoir capacity of shale oil reservoirs were systematically analyzed in combination with core descriptions,high-pressure mercury injection experiments,etc.The research results show that the lithofacies of the Fengcheng Formation shale oil reservoir can be divided into three types:Type Ⅰ siltstone facies has the highest porosity and permeability and the strongest reservoir capacity,Type Ⅱ carbonate rock facies comes second and Type Ⅲ mud shale facies has the lowest.The three lithofacies share similar diagenetic evolutionary sequences,but the dominant diagenetic processes differ. The Fengcheng Formation reservoir is in the middle diagenetic stage B. Its diagenetic evolutionary sequence includes early mechanical compaction,calcite and dolomite cementation,pyritization,early hydrocarbon charging,dissolution,fracturing,late hydrocarbon charging and dissolution.Compaction and carbonate cementation are the main factors for densification,while dissolution and fracturing are key to the diagenetic modification of tight reservoirs,contributing significantly to the formation and improvement of reservoir space.The research results have important guiding significance for deepening the understanding of shale oil reservoir formation mechanisms,improving the shale oil reservoir evaluation system,and "sweet spot" optimization.

Key words: diagenesis, reservoir physical properties, diagenetic evolution, Mahu Sag, “sweet spot”, Fengcheng Formation

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