特种油气藏 ›› 2025, Vol. 32 ›› Issue (3): 47-56.DOI: 10.3969/j.issn.1006-6535.2025.03.006

• 地质勘探 • 上一篇    下一篇

延川地区盒8段储层溶蚀特征及其对物性的影响

黄杏雨1,2, 杜贵超1,2, 何雅雯3,4, 郭睿良1,2, 朱琳1,2, 贾文昊1,2, 王豪1,2, 王凤琴1,2   

  1. 1.西安石油大学地球科学与工程学院,陕西 西安 710065;
    2.西安石油大学陕西省油气成藏地质学重点实验室,陕西 西安 710065;
    3.西北大学地质学系,陕西 西安 710069;
    4.西北大学大陆动力学国家重点实验室,陕西 西安 710069
  • 收稿日期:2024-06-29 修回日期:2025-02-20 出版日期:2025-06-25 发布日期:2025-07-08
  • 通讯作者: 杜贵超(1983—),男,副教授,2007年毕业于新疆石油大学资源勘查工程专业,2012年毕业于中国科学院地质与地球物理研究所矿物学、岩石学及矿床学专业,获博士学位,研究方向为沉积学与储层地质学,现主要从事非常规油气勘探综合地质研究与教学工作。
  • 作者简介:黄杏雨(1999—),女,2022年毕业于忻州师范学院通信工程专业,现为西安石油大学地质工程专业在读硕士研究生,研究方向为沉积学与储层地质学。
  • 基金资助:
    国家自然科学基金“取心保存过程中页岩油轻烃散失动力学机制及规律——以鄂尔多斯盆地长7段为例”(42202175);国家科技重大专项“陆相页岩气成藏主控因素及‘甜点’预测”(2017ZX05039-001)

Dissolution characteristics and impact on properties of the He 8 Reservoirs in the Yanchuan Area

HUANG Xingyu1,2, DU Guichao1,2, HE Yawen3,4, GUO Ruiliang1,2, ZHU Lin1,2, JIA Wenhao1,2, WANG Hao1,2, WANG Fengqin1,2   

  1. 1. School of Earth Sciences and Engineering, Xi′an Shiyou University, Xi′an, Shaanxi 710065, China;
    2. Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi′an Shiyou University, Xi′an, Shaanxi 710065, China;
    3. Department of Geology, Northwest University, Xi′an, Shaanxi 710069, China;
    4. State Key Laboratory of Continental Dynamics (Northwest University), Xi′an, Shaanxi 710069, China
  • Received:2024-06-29 Revised:2025-02-20 Online:2025-06-25 Published:2025-07-08

摘要: 针对鄂尔多斯盆地延川地区盒8段溶蚀作用对储层物性影响不明确的问题,利用压汞、孔渗、岩心观察、薄片鉴定及扫描电镜等多种测试资料,系统开展了盒8段储层砂岩溶蚀作用发育特征及其对储层物性影响研究。结果表明:盒8段为典型的特低孔、致密储层,可划分为石英砂岩、岩屑石英砂岩及岩屑砂岩3种类型储层,储层遭受强烈成岩作用改造,溶蚀作用是形成次生孔隙、改善储层物性的主要因素。3类储层在早成岩B期晚期—中成岩A期均遭受酸性溶蚀作用改造。其中,石英砂岩储层可溶组分较低,溶蚀作用较弱,孔隙类型以粒间孔为主;岩屑石英砂岩遭受强烈溶蚀,产生大量次生孔隙,为溶蚀作用改造形成的优质储层;岩屑砂岩遭受强压实岩屑变形导致砂岩致密化,为致密储层。依据砂岩类型建立了溶蚀作用发育模式。研究结果对盒8段致密砂岩“甜点”划分和有利区预测具有一定指导意义。

关键词: 溶蚀作用, 发育特征, 储层物性, 盒8段, 延川地区, 鄂尔多斯盆地

Abstract: To address the unclear impact of dissolution on the properties of the He 8 Reservoir in the Yanchuan Area of the Ordos Basin, this study used mercury injection, porosity and permeability tests, core observation, thin-section identification, and scanning electron microscopy to analyze the development characteristics of He 8 sandstone reservoir dissolution and its impact on reservoir properties. The results show that the He 8 Member is a typical ultra-low-porosity, tight reservoir divided into three types: quartz sandstone, lithic quartz sandstone, and lithic sandstone. The reservoir has undergone intense diagenesis, with dissolution being the main factor for secondary pore formation and property enhancement. All three reservoir types experienced acidic dissolution during the late early diagenetic stage B to the middle diagenetic stage A. Quartz sandstone reservoirs, with low soluble components and weak dissolution, mainly have intergranular pores. Lithic quartz sandstone, strongly dissolved, forms high-quality reservoirs with abundant secondary pores. Lithic sandstone, subjected to strong compaction rock chip deformation resulting in densification of the sandstone, is a tight reservoir. A dissolution development model was established based on sandstone type. The study results offer a significant reference for "sweet spot" differentiation and favorable area prediction in the He 8 tight sandstone reservoir.

Key words: dissolution, development characteristics, reservoir properties, He 8 Member, Yanchuan Area, Ordos Basin

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