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现代地质 ›› 2025, Vol. 39 ›› Issue (04): 1169-1179.DOI: 10.19657/j.geoscience.1000-8527.2025.016

• 能源地质与工程 • 上一篇    下一篇

川东北普光地区嘉陵江组四—五段成岩演化与卤水储层分布规律

麻乾坤1,2,3(), 崔新宇2, 苏奎2, 吴昆明1,3, 张永生2, 商雯君2   

  1. 1.核工业二三?研究所,湖南 长沙 410007
    2.中国地质科学院矿产资源研究所,北京 100037
    3.湖南省伴生放射性矿产资源评价与综合利用工程技术研究中心,湖南 长沙 410007
  • 出版日期:2025-08-10 发布日期:2025-08-27
  • 作者简介:麻乾坤,男,工程师,1993年出生,主要从事沉积地质和铀矿地质研究工作。Email:2825776768@qq.com
  • 基金资助:
    中国地质调查局地质调查二级项目(DD20190172);中国核工业地质局地勘项目(202223)

Diagenetic Evolution and Distribution of Brine Reservoirs in the 4th to 5th Members of the Jialingjiang Formation, Puguang Area, Northeastern Sichuan

MA Qiankun1,2,3(), CUI Xinyu2, SU Kui2, WU Kunming1,3, ZHANG Yongsheng2, SHANG Wenjun2   

  1. 1. Changsha Uranium Geology Research Institute, CNNC, Changsha, Hunan 410007, China
    2. Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
    3. Hunan Engineering and Technology Research Center for Evaluation and Comprehensive Utilization of Associated Radioactive Mineral Resources, Changsha, Hunan 410007, China
  • Published:2025-08-10 Online:2025-08-27

摘要:

川东北普光地区早三叠世嘉陵江组四—五段整体为海退环境下的陆表浅海沉积,以发育大段不等厚互层的碳酸盐岩与蒸发岩为主要特征。研究业已表明富锂钾卤水的富集与储卤层分布密切相关,但未从成岩作用与演化序列中得到验证,导致对嘉陵江组卤水成因机制认识的重要缺失,如何构建嘉陵江组成岩演化与卤水储层分布的耦合关系,对剖析和探寻优质富锂钾卤水至关重要。通过新近施工的CXD1井对普光地区嘉陵江组四—五段典型成岩作用和成岩阶段演化划分,认为区内有利于储层发育的建设性成岩作用为溶蚀作用、交代作用和应力破裂作用等,由此所形成的储集空间主要为构造裂缝、粒间溶孔和晶间溶孔等。此外,储层物性特征、单井储层评价以及储层连井对比综合剖析表明,普光地区存在优质Ⅱ类储层集中区,储集岩为一套溶孔白云岩,垂向上发育在T1 j 5 4 - 5亚期的灰云坪沉积微相中,北东向延伸稳定,在平面上呈“倒烧瓶状”分布于普光中西部和南部地区。

关键词: 嘉陵江组, 卤水储层, 成岩演化, 普光地区

Abstract:

The 4th to 5th Members of the Early Triassic Jialingjiang Formation in the Puguang area, northeastern Sichuan, were deposited in a shallow epicontinental sea under a regressive environment, characterized by thick, unevenly interbedded carbonate rocks and evaporites. Previous studies have shown that the enrichment of lithium-rich potassium brine is closely related to the distribution of brine reservoirs, but this relationship has not been verified through diagenetic processes and evolutionary sequences, resulting in a critical gap in understanding the genetic mechanism of brines in the Jialingjiang Formation. Establishing the coupling relationship between diagenetic evolution of the Jialingjiang Formation and brine reservoir distribution is crucial for analyzing and exploring high-quality lithium-rich potassium brine.Based on analyses of typical diagenesis and diagenetic stage division of the 4th to 5th Members of the Jialingjiang Formation in the Puguang area using newly drilled Well CXD1, constructive diagenetic processes favorable for reservoir development in the study area include dissolution, metasomatism, and stress fracturing. These processes form reservoir spaces mainly consisting of structural fractures, intergranular dissolved pores, and intercrystalline dissolved pores.Comprehensive analyses of reservoir physical properties, single-well reservoir evaluation, and inter-well correlation indicate that there is a concentrated area of high-quality TypeⅡreservoirs in the Puguang area. The reservoir rock is a set of dissolved-pore dolomite, vertically developed in the gray-dolomite flat sedimentary microfacies of the T1 j 5 4 - 5 substage, with stable northeastward extension. Planar distribution of these reservoirs is “inverted flask-shaped”, concentrated in the central-western and southern parts of Puguang.

Key words: Jialingjiang Formation, brine reservoir, diagenetic evolution, Puguang Area

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