石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (4): 1333-1348.doi: 10.11743/ogg20250420

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地石炭纪—二叠纪煤系全油气系统天然气成藏特征与有序分布模式

丁蓉1,2(), 庞雄奇1,3, 贾承造4(), 熊先钺2, 邓泽5,6, 田文广5, 蒲庭玉1,3, 王飞宇3,6, 林浩1,3, 陈雨萱1,3   

  1. 1.中国石油大学(北京) 地球科学学院,北京 102249
    2.中国石油 煤层气有限责任公司,北京 100028
    3.中国石油大学(北京) 油气资源与工程全国重点实验室,北京 102249
    4.中国石油天然气集团有限公司,北京 100724
    5.中国石油 勘探开发研究院,北京 100083
    6.中国石油大学(北京) 非常规油气科学技术研究院,北京 102249
  • 收稿日期:2025-05-08 修回日期:2025-07-21 出版日期:2025-08-30 发布日期:2025-09-06
  • 通讯作者: 贾承造 E-mail:25670030@qq.com;jiacz@petrochina.com.cn
  • 第一作者简介:丁蓉(1987—),女,高级工程师,煤层气勘探开发及储量管理。E-mail:25670030@qq.com
  • 基金项目:
    中国石油天然气股份有限公司C1类科技项目(2023YQX10110);中国石油天然气股份有限公司“十四五”前瞻性基础性科技重大项目(2021DJ0101);中国石油天然气股份有限公司科技项目(2023ZZ18YJ01)

Natural gas accumulation characteristics and orderly distribution pattern of gas reservoirs in the whole petroleum system of the Carboniferous-Permian coal measures, Ordos Basin

Rong DING1,2(), Xiongqi PANG1,3, Chengzao JIA4(), Xianyue XIONG2, Ze DENG5,6, Wenguang TIAN5, Tingyu PU1,3, Feiyu WANG3,6, Hao LIN1,3, Yuxuan CHEN1,3   

  1. 1.College of Geosciences,China University of Petroleum (Beijing),Beijing 102249,China
    2.Coalbed Methane Company Limited,PetroChina,Beijing 100028,China
    3.State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum (Beijing),Beijing 102249,China
    4.China National Petroleum Corporation,Beijing 100724,China
    5.Research Institute of Petroleum Exploration & Development,PetroChina,Beijing 100083,China
    6.Unconventional Petroleum Research Institute,China University of Petroleum (Beijing),Beijing 102249,China
  • Received:2025-05-08 Revised:2025-07-21 Online:2025-08-30 Published:2025-09-06
  • Contact: Chengzao JIA E-mail:25670030@qq.com;jiacz@petrochina.com.cn

摘要:

自2021年以来,鄂尔多斯盆地石炭纪—二叠纪(C—P)煤系深层煤层气勘探取得重大突破并展示出广阔发展前景,其与盆地C—P多层系致密气和其他类型天然气的成因联系及共采潜力受到广泛关注。基于全油气系统理论及其定量评价方法,对盆地内已发现的各类天然气藏的成因机制和关联性进行了分析,并在此基础上建立了煤系全油气系统天然气成藏与有序分布模式,结果表明:①C—P煤系全油气系统边界范围涉及整个盆地。全油气系统内,自浅而深分别存在浮力成藏下限、油气成藏底限和源岩供烃底限3个动力边界。②在地表与上述3个动力边界之间分别形成了自由、局限和束缚3个动力场。③全油气系统在演化过程中,源岩排出烃在中-浅层自由动力场运聚受浮力作用主导,进入圈闭构造高孔-高渗储层形成煤成常规气藏;源岩排出烃在中-深层局限动力场的运聚受源-储间毛细管力差作用主导,就近进入低孔-低渗储层形成煤成致密气藏;源岩滞留原始烃在束缚动力场的运聚受吸附作用等动力主导,源-储一体形成煤层气藏。④整体自下而上形成的天然气藏呈现出“煤层气—煤成致密气—煤成常规气”的有序分布模式。⑤盆地东部中-浅层因整体抬升和构造裂缝发育,煤成常规气勘探受限,中-深层煤成致密气和煤层气分布面积广、目的层厚度大、富气类型多、资源潜力巨大,是持续勘探的重点方向。

关键词: 化石能源, 全油气系统, 煤层气, 煤系气, 天然气藏, 石炭纪—二叠纪(C—P)煤系, 鄂尔多斯盆地

Abstract:

Since 2021, significant breakthroughs have been achieved in the exploration of deep coalbed methane (CBM) or coal-rock gas in the Carboniferous-Permian coal measures of the Ordos Basin, revealing broad development prospects. Meanwhile, wide attention has been directed to the genetic correlations and commingling production potential between CBM gas and other natural gas, such as tight gas, across multiple Carboniferous-Permian sequences within the basin. Based on the theory and a quantitative evaluation method of the whole petroleum system, we analyze the genetic mechanisms and interrelationships of various natural gas reservoirs that have already been identified in the basin. Accordingly, we establish the accumulation model of natural gas and define the orderly distribution pattern of gas reservoirs in the whole petroleum system of the coal measures. The results indicate that the boundaries of the whole petroleum system in the Carboniferous-Permian coal measures extend across the entire basin. The whole petroleum system exhibits three dynamic boundaries from shallow to deep: the buoyancy-driven hydrocarbon accumulation depth (BHAD), the hydrocarbon accumulation depth limit (HADL), and the active source-rock depth limit (ASDL). Accordingly, three dynamic fields of hydrocarbon accumulation are developed between the Earth’s surface and the three dynamic boundaries, namely the free-hydrocarbon dynamic field, the confined-hydrocarbon dynamic field, and the bound-hydrocarbon dynamic field from top to bottom. During the evolution of the whole petroleum system, hydrocarbons expelled from source rocks migrate and accumulate predominantly under the action of buoyancy in the free-hydrocarbon dynamic field of the intermediate to shallow strata, and then enter into high-porosity, high-permeability reservoirs within traps to form conventional natural gas reservoirs. In contrast, within the confined-hydrocarbon dynamic field of the intermediate to deep strata, hydrocarbon migration and accumulation from source rocks are predominantly driven by differences in capillary pressure between the source rocks and reservoirs. Consequently, these hydrocarbons migrate into adjacent low-porosity, low-permeability reservoirs, resulting in the formation of tight gas reservoirs. In the bound-hydrocarbon dynamic field, primary hydrocarbons retained in source rocks migrate and accumulate predominantly through adsorption, contributing to the formation of CBM reservoirs characterized by integrated source rocks and reservoirs. The natural gas reservoirs in the basin generally display an orderly distribution pattern, with CBM reservoirs, tight gas reservoirs, and conventional gas reservoirs occurring sequentially from bottom to top. In the eastern Ordos Basin, the intermediate to shallow strata contain only limited conventional gas due to the overall uplift and the presence of tectonic fractures. In contrast, the intermediate to deep strata in this region demonstrate widely distributed tight gas, substantial thickness of target strata, varied gas-rich plays, and considerable resource potential, establishing them as an important target for sustainable exploration and development.

Key words: fossil fuel, whole petroleum system, coalbed methane (CBM), coal-measure gas, natural gas reservoir, Carboniferous-Permian coal measures, Ordos Basin

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