Establishment of "Iron Pillar" of Well Daji 70 in Ordos Basin and Its Geological Significance
-
摘要: 为建立石炭-二叠系地层剖面“铁柱子”，在鄂尔多斯盆地东缘大吉地区部署实施大吉70井.该井取心井段1 843.27~2 032.27 m共189 m，岩心收获率100%.通过厘米级岩心精细描述、多尺度CT扫描、地球化学测试与分析等工作，结合地球物理响应特征，构建了鄂尔多斯盆地东南缘晚石炭世-早二叠世等时地层格架，厘清了沉积体系空间配置关系，为沉积环境研究奠定基础.揭示出5#、8#煤层以及4#、6#等薄煤层以半亮-光亮煤为主且天然裂缝网络高度发育（裂隙孔隙度为1.17%~1.19%），有效支撑“高含气、高饱和、高游离”的成藏认识；本溪组-山西组发育5套优质页岩段，为海陆过渡相页岩气的突破提供了直接地质依据.大吉70井“铁柱子”标准剖面的建立，不仅直接验证并支撑了大吉区块深层煤层气的勘探突破，还发现了多套页岩气接替层系，为鄂尔多斯盆地高效勘探开发提供了关键地质证据和决策依据.Abstract: To establish a stratigraphic benchmark for the Carboniferous-Permian formation, Well Daji 70 was deployed and drilled in the Daji area on the eastern margin of the Ordos Basin. This well cored a total of 189 m from 1 843.27 m to 2 032.27 m, achieving a 100% core recovery rate. Through centimeter-scale detailed core description, multi-scale CT scanning, geochemical testing and analysis, combined with geophysical response characteristics, an isochronous stratigraphic framework for the Late Carboniferous to Early Permian on the southeastern margin of the Ordos Basin was constructed. This clarified the spatial configuration of sedimentary systems, laying the foundation for sedimentary environment research. It revealed that the No. 5 and No. 8 coal seams, as well as thin coal seams such as No. 4 and No. 6, are dominated by semi-bright to bright coal with a highly developed natural fracture network (fracture porosity 1.17%-1.19%), effectively supporting the understanding of reservoir formation characterized by "high gas content, high saturation, and high free gas." Additionally, five sets of high-quality shale intervals were identified in the Benxi Formation to Shanxi Formation, providing direct geological evidence for breakthroughs in transitional marine-terrestrial shale gas exploration. The establishment of the "Iron Pillar" in Well Daji 70 not only directly verified and supported the exploration breakthrough of deep coalbed gas in the Daji block but also revealed multiple shale gas replacement layers, offering critical geological evidence and decision-making support for efficient exploration and development in the Ordos Basin.
-
Key words:
- Ordos Basin /
- "Iron Pillar" project /
- continuous coring /
- coalbed methane /
- shale gas /
- geological significance /
- petroleum geology
-
图 1 大吉地区煤系非常规天然气立体成藏模式示意图（据杨华等，2015修改）
Fig. 1. Schematic diagram of three-dimensional accumulation model for unconventional natural gas in coal measures of eastern Ordos Basin (modified after Yang et al., 2015)
图 3 大吉70井取心不同岩性厚度
Fig. 3. Thicknesses of different lithologies in the coring results of Well Daji 70
图 4 大吉70“铁柱子”建设技术路线图
Fig. 4. Technical roadmap for the construction of the Daji 70 "Iron Pillar"
图 5 二级和三级层序界面特征
a. 本溪组与马家沟组界线特征；b. 马家沟组岩性特征；c. 晋祠砂岩及上覆深灰色页岩；d. 晋祠砂岩与下伏地层分界特征；e. 8#煤与顶部灰岩接触特征；f. 8#煤层特征；g. 7#煤层与顶部灰岩接触特征；h. 北岔沟砂岩与下伏地层接触特征；i~l. 山西组泥岩‒砂岩突变接触面
Fig. 5. Characteristics of second- and third-order sequence boundaries
图 8 大吉70井裂隙系统精细描述
8-2#煤层，1 991.30~1 991.95 m
Fig. 8. Fine characterization of multi-scale pore-fracture systems in Well Daji 70
图 10 大吉70井本溪组、太原组、山西组页岩岩相划分图版
Fig. 10. Shale facies classification chart for the Benxi, Taiyuan, and Shanxi formations of Well Daji 70
图 11 本溪组岩心特征
a~c. 大吉70井，本1段深水潟湖相页岩，双壳类生屑发育；d~f. 大吉70井，本2段深水潟湖相页岩，发育硅质粉砂纹层、层状黄铁矿
Fig. 11. Core characteristics of the Benxi Formation
图 12 太原组岩心特征
a~c.大吉70井，太1段深水潟湖相页岩，端面见碳化植物碎屑；d~f. 大吉70井，太2段深水潟湖相页岩，硅质粉砂纹层发育
Fig. 12. Core characteristics of the Taiyuan Formation
图 13 山西组岩心特征
a~c.大吉70井，山23亚段2~3小层（1 915.94~1 920.20 m），深水潟湖相富有机质页岩；d~f. 大吉70井，山23亚段1小层（1 934.37~1 939.65 m）海湾相富有机质页岩
Fig. 13. Core characteristics of the Shanxi Formation
表 1 大吉70井煤层发育特征
Table 1. The development characteristics of the coal seam in Well Daji 70
煤层编号 厚度(m) 煤层结构类型 煤岩类型 裂隙特征 顶底板岩性 沉积环境 各煤层关键差异点 4# 0.47 二分型 光亮煤 层状裂隙 顶板：泥岩；底板：炭质泥岩 间湾沼泽 横向稳定性差，含气性高（全烃＞10%） 5# 3.88 三分型 光亮煤+半亮煤 中型网状裂隙，方解石充填 顶板：碳质泥岩→粉砂岩（过渡） 泥炭沼泽 最优封盖条件，原生结构煤 6# 0.57 二分型 镜煤+亮煤 层状裂隙 顶板：碳酸盐潮坪（海侵终止） 潮坪沼泽 聚煤作用受海侵中断 7# 0.25 简单结构煤层 光亮煤为主，次为暗淡煤 大裂隙方解石充填 顶板：碳酸盐潮坪（海侵终止） 潮坪沼泽 厚度较薄 8# 6.07 二分型 光亮煤+半亮煤 裂隙密度3.93条/cm3（网状） 顶板：灰岩→泥岩→灰岩（接触） 泥炭沼泽 储集优势段：8#-1 9# 0.44 二分型 镜煤+亮煤 层状裂隙 顶板：灰黑页岩；底板：粉砂质泥岩 潮坪沼泽 厚度波动大 
下载: 导出CSV
表 2 大吉70井泥页岩段厚度分布
Table 2. Distribution layers and thickness of shale in Well Daji 70
发育层段 本二段 本一段 太1+太2段 山23亚段 山21+2亚段 具体井段埋深(m） 2 012.87~2 018.90 1 996.48~2 004.97 1 956.23~1 982.20 1 933.20~1 956.23 1 898.65~1 904.37 页岩厚度（m） 6.03 8.49 6.53 19.16 6.70
下载: 导出CSV
表 3 大吉70井页岩矿物组成（%）及总有机碳（TOC）含量（%）
Table 3. Mineral composition (%) and total organic carbon (TOC, %) of shales from Well Daji 70
校正岩心深度
（m）层位 编号 石英（%） 斜长石（%） 方解石（%） 菱铁矿（%） 黄铁矿（%） 锐钛矿（%） 金红石（%） 黏土矿物（%） TOC（%） 平均TOC（%） 1 883.87 山21 1 44.3 4.4 0.0 1.2 0.0 0.8 0.0 49.3 0.55 0.43 1 887.97 2 36.4 15.2 0.0 0.4 0.0 0.4 0.0 47.6 0.30 1 918.07 山23 3 34.8 1.8 0.0 1.9 0.0 0.7 0.0 60.8 2.86 4.02 1 919.27 4 22.4 0.6 0.0 0.4 4.6 0.4 0.0 71.6 8.68 1 919.67 5 26.6 0.8 0.0 0.4 5.0 0.6 0.0 66.6 9.63 1 927.47 6 46.3 1.2 0.0 0.4 2.9 0.7 0.0 48.5 1.64 1 927.87 7 54.4 0.9 0.0 2.7 0.6 0.3 0.0 41.1 1.63 1 934.97 8 1.4 0.0 0.0 0.0 0.0 0.4 0.2 98.0 2.36 1 935.77 9 1.0 0.0 0.0 0.0 2.3 0.6 0.2 95.9 0.74 1 952.30 10 33.3 0.0 0.0 0.0 0.0 0.6 0.0 66.1 4.66 1 955.47 太1段 11 37.4 0 0 0 11.3 0 0 51.3 4.25 1.68 1 957.40 12 42.6 0 0 0 1.9 0 0 55.5 0.18 1 961.43 13 52.1 0 0 0 0 0 0 45.6 0.29 1 971.83 14 63 0 0 0 3.9 0 0 33.1 1.24 1 973.57 15 39.1 0 0 1.6 8.4 0 0 50.9 2.48 1 994.35 本1段 16 11.7 0.7 0 9.1 1 0 0 77.5 1.41 2.40 1 995.49 17 12.5 0 8.4 6.6 2.8 0 0 69.7 2.22 2 000.29 18 19.5 1.3 0 0 10.2 0 0 67.8 1.39 2 000.56 19 14.9 0 0 0 9.9 0 0 74.1 3.58 2 000.99 20 18.6 1.1 0 0 12.5 0 0 66.5 3.96 2 005.07 21 31.5 0 0 4.3 2.8 0 0 59.2 1.35 2 013.04 22 29.4 2.2 0 1.6 6.7 0 0 59.6 2.91 2 013.82 本2段 23 31.2 2.9 0 8.6 0.9 0 0 55.5 4.81 3.04 2 014.40 24 31.4 3.8 0 8 1.4 0 0 54.5 3.14 2 015.06 25 22.2 2.6 0 7.2 1.2 0 0 66.2 2.22 2 015.60 26 28 2.1 0 5.7 1.2 0 0 62.6 2.41 2 016.29 27 22.2 2.6 0 7.2 1.2 0 0 66.2 2.63
下载: 导出CSV
-
Castro-Alvarez, F., Marsters, P., Ponce de León Barido, D., et al., 2018. Sustainability Lessons from Shale Development in the United States for Mexico and Other Emerging Unconventional Oil and Gas Developers. Renewable and Sustainable Energy Reviews, 82: 1320-1332. doi: 10.1016/j.rser.2017.08.082 Guo, Y. H., Liu, H. J., Chen, M. J., 2004. Late Paleozoic Sedimentary Evolution in the Ordos Region. China University of Mining and Technology Press, Xuzhou (in Chinese). Li, X. W., Liu, H. T., Ning, C. B., et al., 2025. The Hydrocarbon Generation Characteristics of the Upper Paleozoic Coaly Bearing Source Rocks and Its Main Controlling Factors in the North of the Jizhong Depression. Earth Science, 50(5): 1917-1932 (in Chinese with English abstract). Li, Y., Xu, L. F., Zhang, S. R., et al., 2023. Gas Bearing System Difference in Deep Coal Seams and Corresponded Development Strategy. Journal of China Coal Society, 48(2): 900-917 (in Chinese with English abstract). Liu, H. L., Zou, C. N., Yin, S., et al., 2024. Formation, Distribution, Sweet Spot Evaluation and Development Prospect of Coal-Measure Gas in China. Natural Gas Industry, 44(10): 1-21 (in Chinese with English abstract). Niu, X. B., Yu, J., Xu, W. L., et al., 2024. Reservoir-Forming Geological Conditions and Exploration Directions of Upper Paleozoic Coal-Rock Gas in the Ordos Basin. Natural Gas Industry, 44(10): 33-50 (in Chinese with English abstract). Qin, Y., 2025. Advances and Trends of Modern and Contemporary Research on the Geology of Coal-Measure Minerals in China. Coal Geology & Exploration, 53(1): 12-35 (in Chinese with English abstract). Qin, Y., Shen, J., Shen, Y. L., 2016. Joint Mining Compatibility of Superposed Gas-Bearing Systems: A General Geological Problem for Extraction of Three Natural Gases and Deep CBM in Coal Series. Journal of China Coal Society, 41(1): 14-23 (in Chinese with English abstract). Qin, Y., Shen, J., Shen, Y. L., et al., 2019. Geological Causes of High Production of Coal-Measure Gas in the Surat Basin and Its Implications. Acta Petrolei Sinica, 40(10): 1147-1157 (in Chinese with English abstract). Qin, Y., Shen, J., Shi, R., 2022. Strategic Value and Choice on Construction of Large CMG Industry in China. Journal of China Coal Society, 47(1): 371-387 (in Chinese with English abstract). Shang, G. X., 1997. Study on Late Paleozoic Coal Geology of the North China Platform. Shanxi Science and Technology Press, Taiyuan (in Chinese). Shen, J., Li, K. X., Zhang, H. W., et al., 2021. The Geochemical Characteristics, Origin, Migration and Accumulation Modes of Deep Coal-Measure Gas in the West of Linxing Block at the Eastern Margin of Ordos Basin. Journal of Natural Gas Science and Engineering, 91: 103965. https://doi.org/10.1016/j.jngse.2021.103965 Shen, J., Qin, Y., Zhang, B., et al., 2018. Superimposing Gas-Bearing System in Coal Measures and Its Compatibility in Linxing Block, East Ordos Basin. Journal of China Coal Society, 43(6): 1614-1619 (in Chinese with English abstract). Shi, R., Bian, L. H., Zhang, W., et al., 2025. Prediction Model of Free Gas Content in Deep Coal Seams Based on Effective Porosity. Journal of China University of Mining & Technology, 54(1): 161-171 (in Chinese with English abstract). Sun, F. J., Zhou, G. X., Tian, W. G., et al., 2024. Definition, Connotation, Formation and Application of Coalbed Methane System: A Case Study on the Carboniferous-Permian Coal Seams in the Ordos Basin. Natural Gas Industry, 44(7): 42-53 (in Chinese with English abstract). Xiong, X. Y., Yan, X., Xu, F. Y., et al., 2023. Analysis of Multi-Factor Coupling Control Mechanism, Desorption Law and Development Effect of Deep Coalbed Methane. Acta Petrolei Sinica, 44(11): 1812-1826, 1853 (in Chinese with English abstract). Xu, C. G., Ji, H. Q., Wang, C. W., et al., 2024. Enrichment Patterns and Exploration Countermeasures of Deep Coalbed Methane in the Linxing-Shenfu Block on the Eastern Margin of the Ordos Basin. Coal Geology & Exploration, 52(8): 1-11 (in Chinese with English abstract). Xu, F. Y., Xiong, X. Y., Hou, W., et al., 2025. Upgrading of Deep Coalbed Methane Industry and Establishment of the "Eight-in-One" System. Acta Petrolei Sinica, 46(2): 289-305 (in Chinese with English abstract). Yan, X., Xu, F. Y., Xiong, X. Y., et al., 2025. Key Experimental Technologies and Development Directions for Deep Coalbed Methane Exploration and Development. Coal Geology & Exploration, 53(1): 128-141 (in Chinese with English abstract). Yang, H., Liu, X. S., Yan, X. X., et al., 2015. The Shenmu Gas Field in the Ordos Basin: Its Discovery and Reservoir-Forming Geological Characteristics. Natural Gas Industry, 35(6): 1-13 (in Chinese with English abstract). Yang, X. C., Xu, F. Y., Wang, H. Y., et al., 2022. Exploration and Development Process of Coalbed Methane in Eastern Margin of Ordos Basin and Its Enlightenment. Coal Geology & Exploration, 50(3): 30-41 (in Chinese with English abstract). Zhao, X. Z., Jin, F. M., Zhou, L. H., et al., 2022. Breakthrough and Significance of Shale Oil Exploration in Member 1 of the Shahejie Formation of Risk Exploratory Well Qiye 1H in the Bohai Bay Basin. Acta Petrolei Sinica, 43(10): 1369-1382 (in Chinese with English abstract). Zhao, X. Z., Zhou, L. H., Zhao, M., et al., 2019. Breakthrough and Practice of Industrial Development on Continental Shale Oil: A Case Study on Kong-2 Member in Cangdong Sag, Bohai Bay Basin. China Petroleum Exploration, 24(5): 589-600 (in Chinese with English abstract). Zhou, L. H., Chen, C. W., Yang, F., et al., 2023. Research and Breakthrough of Benefit Shale Oil Development in Cangdong Sag, Bohai Bay Basin. China Petroleum Exploration, 28(4): 24-33 (in Chinese with English abstract). Zhou, L. H., Xiong, X. Y., Li, Y., et al., 2025. Revolutionary Breakthroughs and Key Theories and Technologies in Deep Coalbed Methane Development. Natural Gas Industry, 45(5): 17-30 (in Chinese with English abstract). Zhou, L. H., Zhao, X. Z., Chai, G. Q., et al., 2020. Key Exploration & Development Technologies and Engineering Practice of Continental Shale Oil: A Case Study of Member 2 of Paleogene Kongdian Formation in Cangdong Sag, Bohai Bay Basin, East China. Petroleum Exploration and Development, 47(5): 1059-1066 (in Chinese with English abstract). Zou, C. N., Zhao, Q., Liu, H. L., et al., 2025. China's Breakthrough in Coal-Rock Gas and Its Significance. Natural Gas Industry, 45(4): 1-18 (in Chinese with English abstract). 郭英海, 刘焕杰, 陈孟晋, 2004. 鄂尔多斯地区晚古生代沉积演化. 徐州: 中国矿业大学出版社. 李熹微, 刘海涛, 宁才倍, 等, 2025. 冀中坳陷北部上古生界煤系烃源岩生烃特征及发育的主控因素. 地球科学, 50(5): 1917-1932. 李勇, 徐立富, 张守仁, 等, 2023. 深煤层含气系统差异及开发对策. 煤炭学报, 48(2): 900-917. 刘翰林, 邹才能, 尹帅, 等, 2024. 中国煤系气形成分布、甜点评价与展望. 天然气工业, 44(10): 1-21. 牛小兵, 喻健, 徐旺林, 等, 2024. 鄂尔多斯盆地上古生界煤岩气成藏地质条件及勘探方向. 天然气工业, 44(10): 33-50. 秦勇, 2025. 中国煤系矿产近现代地质研究进展与走向. 煤田地质与勘探, 53(1): 12-35. 秦勇, 申建, 沈玉林, 等, 2019. 苏拉特盆地煤系气高产地质原因及启示. 石油学报, 40(10): 1147-1157. 秦勇, 申建, 沈玉林, 2016. 叠置含气系统共采兼容性——煤系"三气"及深部煤层气开采中的共性地质问题. 煤炭学报, 41(1): 14-23. 秦勇, 申建, 史锐, 2022. 中国煤系气大产业建设战略价值与战略选择. 煤炭学报, 47(1): 371-387. 尚冠雄, 1997. 华北地台晚古生代煤地质学研究. 太原: 山西科学技术出版社. 申建, 秦勇, 张兵, 等, 2018. 鄂尔多斯盆地东缘临兴区块煤系叠置含气系统及其兼容性. 煤炭学报, 43(6): 1614-1619. 史锐, 边利恒, 张伟, 等, 2025. 基于有效孔隙度的深部煤层游离气含量预测模型. 中国矿业大学学报, 54(1): 161-171. 孙粉锦, 周国晓, 田文广, 等, 2024. 煤层气系统的定义、内涵、形成及应用——以鄂尔多斯盆地石炭系-二叠系煤层为例. 天然气工业, 44(7): 42-53. 熊先钺, 闫霞, 徐凤银, 等, 2023. 深部煤层气多要素耦合控制机理、解吸规律与开发效果剖析. 石油学报, 44(11): 1812-1826, 1853. 徐长贵, 季洪泉, 王存武, 等, 2024. 鄂尔多斯盆地东缘临兴-神府区块深部煤层气富集规律与勘探对策. 煤田地质与勘探, 52(8): 1-11. 徐凤银, 熊先钺, 侯伟, 等, 2025. 深部煤层气产业升级与"八个一体化"体系的建立. 石油学报, 46(2): 289-305. 闫霞, 徐凤银, 熊先钺, 等, 2025. 深部煤层气勘探开发关键实验技术及发展方向. 煤田地质与勘探, 53(1): 128-141. 杨华, 刘新社, 闫小雄, 等, 2015. 鄂尔多斯盆地神木气田的发现与天然气成藏地质特征. 天然气工业, 35(6): 1-13. 杨秀春, 徐凤银, 王虹雅, 等, 2022. 鄂尔多斯盆地东缘煤层气勘探开发历程与启示. 煤田地质与勘探, 50(3): 30-41. 赵贤正, 金凤鸣, 周立宏, 等, 2022. 渤海湾盆地风险探井歧页1H井沙河街组一段页岩油勘探突破及其意义. 石油学报, 43(10): 1369-1382. 赵贤正, 周立宏, 赵敏, 等, 2019. 陆相页岩油工业化开发突破与实践——以渤海湾盆地沧东凹陷孔二段为例. 中国石油勘探, 24(5): 589-600. 周立宏, 陈长伟, 杨飞, 等, 2023. 渤海湾盆地沧东凹陷页岩油效益开发探索与突破. 中国石油勘探, 28(4): 24-33. 周立宏, 熊先钺, 李勇, 等, 2025. 深层煤层(岩)气革命性突破及关键理论与技术. 天然气工业, 45(5): 17-30. 周立宏, 赵贤正, 柴公权, 等, 2020. 陆相页岩油效益勘探开发关键技术与工程实践——以渤海湾盆地沧东凹陷古近系孔二段为例. 石油勘探与开发, 47(5): 1059-1066. 邹才能, 赵群, 刘翰林, 等, 2025. 中国煤岩气突破及意义. 天然气工业, 45(4): 1-18. -
点击查看大图
计量
- 文章访问数: 76
- HTML全文浏览量: 34
- PDF下载量: 22
- 被引次数: 0
