石油与天然气地质 ›› 2024, Vol. 45 ›› Issue (6): 1736-1754.doi: 10.11743/ogg20240618

• 油气地质 • 上一篇    下一篇

海拉尔盆地呼和湖凹陷深层煤岩气赋存条件及勘探方向

白雪峰1,2(), 高庚1,3(), 王彪1,3, 李敬生1,3, 李军辉1,3, 徐慧4, 马文娟1,3, 刘璐1,3   

  1. 1.多资源协同陆相页岩油绿色开采全国重点实验室,黑龙江 大庆 163712
    2.大庆油田有限责任公司,黑龙江 大庆 163458
    3.大庆油田有限责任公司 勘探开发研究院,黑龙江 大庆 163712
    4.常州大学,江苏 常州 213164
  • 收稿日期:2024-06-08 修回日期:2024-10-26 出版日期:2024-12-30 发布日期:2024-12-31
  • 通讯作者: 高庚 E-mail:bxf@petrochina.com.cn;ggao_njucsu@petrochina.com.cn
  • 第一作者简介:白雪峰(1979—),男,博士、教授级高级工程师,油气勘探开发与管理。E‑mail: bxf@petrochina.com.cn
  • 基金项目:
    国家科技重大专项(2016ZX0504);中国石油天然气股份有限公司重大科技专项(2017E-14);大庆油田有限责任公司科研项目(202121KT002)

Occurrence conditions and exploration targets of deep coal-rock gas in the Huhehu Sag, Hailar Basin

Xuefeng BAI1,2(), Geng GAO1,3(), Biao WANG1,3, Jingsheng LI1,3, Junhui LI1,3, Hui XU4, Wenjuan MA1,3, Lu LIU1,3   

  1. 1.State Key Laboratory of Continental Shale Oil,Daqing,Heilongjiang 163712,China
    2.Daqing Oilfield Limited Company,Daqing,Heilongjiang 163458,China
    3.Research Institute of Exploration and Development,Daqing Oilfield Limited Company,Daqing,Heilongjiang 163712,China
    4.Changzhou University,Changzhou,Jiangsu 213164,China
  • Received:2024-06-08 Revised:2024-10-26 Online:2024-12-30 Published:2024-12-31
  • Contact: Geng GAO E-mail:bxf@petrochina.com.cn;ggao_njucsu@petrochina.com.cn

摘要:

海拉尔盆地呼和湖凹陷白垩系南屯组二段(南二段)已发现油气藏,但对其中的深层煤岩气赋存条件及勘探方向研究较少。分析了烃源岩、沉积和构造等油气成藏基础条件,研究了深层煤储层发育特征及含气规律,探讨了呼和湖凹陷深层煤岩气赋存条件,提出了下一步勘探方向。研究结果表明:①南屯组发育泥岩及煤岩2套成熟源岩,深层煤岩气具有良好的气源物质基础。②断陷湖盆沼泽发育,成煤环境优越,初始期煤岩厚度大,煤-泥共生;稳定期和萎缩期煤岩厚度小,砂-煤共生。③缓坡断阶带煤岩厚度小,含气量低;洼槽带及陡坡带煤岩厚度大,割理裂隙发育,微裂隙沟通有机孔,连通性好,孔-缝体系发育,富游离气。④早期断裂体系为深层煤岩气垂向与侧向运移提供通道。⑤呼和湖凹陷预测深层煤岩气资源量1.79×1012 m3,勘探潜力大,将成为断陷盆地重要风险勘探新领域,洼槽带和陡坡带是深层煤岩气最有利的勘探方向。

关键词: 风险勘探, 洼槽带, 陡坡带, 深层煤岩气, 南屯组二段, 呼和湖凹陷, 海拉尔盆地

Abstract:

Hydrocarbon reservoirs have been identified in the 2nd member of the Cretaceous Nantun Formation (also referred to as the Nan 2 Member) in the Huhehu Sag, Hailar Basin. However, limited studies have been conducted on the occurrence conditions and exploration targets of deep coal-rock gas therein. In this study, we analyze the fundamental conditions for hydrocarbon accumulation, including source rocks, deposits, and structures, in the Huhehu Sag and examine the developmental characteristics and gas-bearing features of deep coal reservoirs. Accordingly, we explore the occurrence conditions of deep coal-rock gas in the sag and propose potential exploration targets. The findings reveal that in Nantun Formation there are two suites of mature source rocks in the mudstones and coals, which provide a favorable material basis for the deep coal-rock gas generation and accumulation. During the deposition of the Nan 2 Member, Hailar Basin, a faulted lacustrine basin, exhibits swamps, which create a favorable coal-forming setting. The initial extension stage of the basin witnessed the formation of thick coals and coal-mudstone coexistence, while its stable extension and contraction stages featured thin coals and sandstone-coal coexistence. The ramp-faulted terrace zone exhibits thin coals and low gas content. In contrast, the trough and steep slope zones are characterized by thick coal rocks and well-developed cleats, with organic pores interconnected by microfractures, contributing to high connectivity and a well-developed pore-fracture system. So it is rich in free gas. The fault system formed in the early extension stage provides pathways for the vertical and lateral migration of deep coal-rock gas. The Huhehu Sag exhibits deep coal-rock gas resources predicted at 1.79×1012 m3, suggesting considerable exploration potential and establishing this sag as an important new risk exploration target in the faulted lacustrine basin. Additionally, the trough and steep-slope zones are identified as the most favorable exploration targets for deep coal-rock gas.

Key words: risk exploration, trough zone, steep-slope zone, deep coal-rock gas, the 2nd member of the Nantun Formation (Nan 2 Member), Huhehu Sag, Hailar Basin

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