中国石油勘探 ›› 2025, Vol. 30 ›› Issue (4): 106-117.DOI: 10.3969/j.issn.1672-7703.2025.04.008

• 石油地质 • 上一篇    下一篇

鄂尔多斯盆地大宁—吉县区块深层8 号煤夹矸特征及其与产能关系分析

黄红星1,2,石军太3,陈国辉4,王峰1,2,陶自强1,2,刘莹1,2,朱文涛2,李小刚2,赵浩阳1,2,常益行2,林海鲲1,2,何睿4   

  1. 1 中石油煤层气有限责任公司;2 中联煤层气国家工程研究中心有限责任公司;3 中国石油大学( 北京) 煤层气研究中心;4 北京润泽创新科技有限公司
  • 出版日期:2025-07-15 发布日期:2025-07-15
  • 作者简介:黄红星(1980-),男,湖北仙桃人,硕士,2009年毕业于中国石油大学(北京),高级工程师,现主要从事煤层气开发及生产研究工作。地址:北京市朝阳区太阳宫南街13号楼中石油煤层气有限责任公司,邮政编码:100028。
  • 基金资助:
    国家自然科学基金项目“深部煤层流体作用与煤层气富集产出机理”(U24B2018);中石油煤层气有限责任公司科技项目“煤系储层数字化精细评价研究”(2023-KJ-19)、“深层煤层气(煤岩气)开发方案编制和跟踪优化研究”(2025-KJ-08)。

Characteristics of gangues in deep No.8 coal seam and their relationship with production capacity in Daning–Jixian block, Ordos Basin

Huang Hongxing1,2,Shi Juntai3,Chen Guohui4, Wang Feng1,2,Tao Ziqiang1,2, Liu Ying1,2,Zhu Wentao2,Li Xiaogang2,Zhao Haoyang1,2,Chang Yihang2, Lin Haikun1,2,He Rui4   

  1. 1 PetroChina Coalbed Methane Co., Ltd.; 2 China United Coalbed Methane National Engineering Research Center Co., Ltd.;3 Coalbed Methane Research Center, China University of Petroleum (Beijing); 4 Beijing Runze Innovation Technology Co., Ltd.
  • Online:2025-07-15 Published:2025-07-15

摘要: 鄂尔多斯盆地东部大宁—吉县区块深层8号煤具有良好的勘探潜力,但煤层夹矸发育,其分布特征及对产能的影响机制尚不清楚。通过对本区8口井的全直径螺旋CT 扫描,并结合煤岩的工业分析、孔隙结构、矿物成分等测试资料,对8号煤层夹矸进行高精度识别和表征,进而对夹矸发育特征及其与含气量、储层敏感性和产能的关系进行了综合评价。结果表明:大宁—吉县区块8号煤夹矸广泛发育,单井夹矸厚度占比约25.16%,发育密度约2.3 层/m,单层厚度为0.02~1.57m,一般厚度小于1m,夹矸累计厚度为0.20~2.66m ;夹矸含碳量低、微孔占比少、吸附性差,导致其生气能力及吸附能力均弱于煤层;夹矸中黏土矿物含量平均为61.61%,且以伊/ 蒙混层、高岭石及伊利石为主,容易发生水敏及速敏,对压裂后渗流通道的稳定性与有效性产生不利影响;夹矸含量、平均厚度、单层最大厚度与日产气量呈较好的负相关关系,分析认为夹矸的发育不仅降低了煤层总体的有机质含量,同时增强了煤层非均质性和敏感性,并影响了单井产能。研究成果可以为大宁—吉县区块深层煤层气压裂方案设计及合理排采措施制定提供科学依据。

关键词: 大宁—吉县区块, 深层, 8号煤, 螺旋CT 扫描, 夹矸, 分布特征, 含气性, 产能

Abstract: The deep No.8 coal seam in Daning–Jixian block in the eastern Ordos Basin demonstrates promising exploration potential. However, there is unclear understanding of the distribution characteristics and influence mechanisms on production capacity of the well-developed coal gangues. The high-precision identification and characterization of gangues in No.8 coal seam have been conducted by full-diameter spiral CT scanning for core section from eight wells in the study area, as well as coal rock laboratory data such as proximate analysis, pore structure, and mineral composition. Furthermore, a comprehensive evaluation has been performed on the development characteristics of gangues and their relationship with gas content, reservoir sensitivity, and production capacity. The results indicate that gangues in No.8 coal seam are extensively distributed in Daning–Jixian block, with a thickness proportion of approximately 25.16% in individual wells, a density of about 2.3 layers/m, a single-layer thickness of 0.02–1.57 m (generally <1 m), and the cumulative thickness of 0.20–2.66 m. The gangues are featured by low carbon content, low proportion of micropores, and poor adsorption performance, resulting in weaker gas generation and adsorption capacity compared to coal seams. The average clay mineral content in gangues is 61.61%, dominated by illite/montmorillonite mixed-layer minerals, kaolinite,and illite, which are prone to water and velocity sensitivity, adversely affecting the stability and effectiveness of post-fracturing flow pathways.It shows distinctly negative correlation between gangue content, average thickness, maximum single-layer thickness, and daily gas production.The study concludes that the gangues not only reduce the overall organic content of coal seams but also enhance reservoir heterogeneity and sensitivity, ultimately reducing well production capacity. These findings provide a scientific basis for optimizing hydraulic fracturing design and rational drainage strategy of deep coalbed methane in Daning–Jixian block.

Key words: Daning–Jixian block, deep formation, No.8 coal seam, spiral CT scanning, gangue, distribution characteristics, gas content, production capacity

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