石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (6): 1907-1926.doi: 10.11743/ogg20250611

• 油气地质 • 上一篇    下一篇

川东五峰组-龙马溪组深层-超深层页岩储层特征与差异

孙川翔1,2,3(), 张珂4, 聂海宽1,2,3(), 苏海琨4, 万成祥1,2,3, 边瑞康1,2,3, 俞凌杰1,2, 杨振恒1,2   

  1. 1.页岩油气富集机理与有效开发国家重点实验室,北京 102206
    2.中国石油化工股份有限公司 石油勘探开发研究院,北京 102206
    3.中国石油化工集团公司 页岩油气勘探开发重点实验室,北京 102206
    4.中国地质大学(北京) 能源学院,北京 100083
  • 收稿日期:2025-04-01 修回日期:2025-06-30 出版日期:2025-12-30 发布日期:2025-12-25
  • 通讯作者: 聂海宽 E-mail:suncx.syky@sinopec.com;niehk.syky@sinopec.com
  • 第一作者简介:孙川翔(1990—)硕士、副研究员,非常规油气地质。E‑mail: suncx.syky@sinopec.com
  • 基金项目:
    国家自然科学重点基金项目(42130803);国家自然科学基金项目(41872124);中国石化科技项目(P23132)

Comparative analysis of deep and ultra-deep shale reservoirs in the Wufeng-Longmaxi formations, eastern Sichuan Basin

Chuanxiang SUN1,2,3(), Ke ZHANG4, Haikuan NIE1,2,3(), Haikun SU4, Chengxiang WAN1,2,3, Ruikang BIAN1,2,3, Lingjie YU1,2, Zhenheng YANG1,2   

  1. 1.State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 102206,China
    2.Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 102206,China
    3.Key Laboratory of Shale Oil/Gas Exploration and Production,SINOPEC,Beijing 102206,China
    4.School of Energy Resources,China University of Geosciences (Beijing),Beijing 100083,China
  • Received:2025-04-01 Revised:2025-06-30 Online:2025-12-30 Published:2025-12-25
  • Contact: Haikuan NIE E-mail:suncx.syky@sinopec.com;niehk.syky@sinopec.com

摘要:

四川盆地五峰组-龙马溪组深层-超深层页岩气资源潜力大,但其储层特征与中-浅层存在显著差异。以川东凤来和梁平地区深层(埋深> 3 500 m)和超深层(埋深> 4 500 m)页岩为重点研究对象,通过场发射扫描电镜(FE-SEM)观测、高压压汞-气体吸附联合孔隙表征、聚焦离子束扫描电镜(FIB-SEM)三维孔隙重构、覆压孔-渗测试及流体包裹体显微测温等实验分析,结合与涪陵焦石坝中-浅层页岩储层的系统对比,阐明了深层-超深层页岩储层特征及其与中-浅层差异的主控因素。研究表明:①川东深层-超深层富有机质硅质页岩仍保持良好储集性能,表现为有机质孔主导的孔隙结构、相对较高的孔隙度和渗透率,并具有较强抗压实能力和有限裂缝-流体活动。②与中-浅层页岩储层相比,深层-超深层页岩无机质孔和微裂缝发育程度显著降低,介孔-宏孔占比增加,且受上覆压力影响渗透率显著下降。③深层-超深层与中-浅层储层差异主要受构造位置、矿物组分、成岩作用、构造演化和裂缝-流体活动共同控制。研究成果为四川盆地深层-超深层页岩气勘探开发提供了地质依据。

关键词: 主控因素, 孔隙结构, 储层特征, 页岩, 深层-超深层, 川东地区

Abstract:

The Wufeng-Longmaxi formations in the Sichuan Basin hold considerable potential for deep and ultra-deep shale gas resources. However, their deep and ultra-deep reservoirs exhibit significantly different characteristics compared to their medium and shallow counterparts. In this study, we investigate deep (burial depth > 3 500 m) and ultra-deep (burial depth > 4 500 m) shales in the Fenglai and Liangping areas in the eastern Sichuan Basin through a series of experiments and analyses, including field emission scanning electron microscopy (FE-SEM), pore characterization using high-pressure mercury injection (HPMI) combined with gas adsorption, 3D pore reconstruction using focused ion beam-scanning electron microscopy (FIB-SEM), porosity and permeability tests under confining pressure, and fluid inclusion microthermometry. Furthermore, comparative analysis is conducted with the shallow to medium-depth shale reservoirs in the Jiaoshiba area, Fuling shale gas field. Accordingly, the characteristics of deep and ultra-deep shale reservoirs in the Wufeng-Longmaxi formations in both areas are elucidated, and the primary factors that distinguish them from the medium and shallow shale reservoirs are identified. The results indicate that the deep and ultra-deep organic-rich siliceous shales in the eastern Sichuan Basin still retain favorable reservoir properties, including organic matter-dominated pore systems, relatively high porosity and permeability, strong resistance to compaction, and limited fracture-fluid activity. Compared to the medium and shallow shale reservoirs, the deep and ultra-deep shales exhibit a significantly decreased density of inorganic pores and microfractures, a higher proportion of meso-to-macro-pores, and markedly lower permeability under the influence of higher overburden pressure. These differences are primarily controlled by the combined effects of tectonic location, mineral composition, diagenesis, tectonic evolution, and fracture-fluid activity. These findings serve to provide a geological basis for the exploration and exploitation of deep and ultra-deep shale gas resources in the Sichuan Basin.

Key words: primary controlling factor, pore structure, reservoir characteristics, ultra-deep shale, deep shale, eastern Sichuan Basin

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