特种油气藏 ›› 2021, Vol. 28 ›› Issue (2): 27-33.DOI: 10.3969/j.issn.1006-6535.2021.02.004

• 地质勘探 • 上一篇    下一篇

鄂尔多斯盆地中部奥陶系马四段天然气成藏主控因素

任海姣1,2, 吴伟涛2,3, 赵靖舟2,3, 陈梦娜1   

  1. 1.中国石油新疆油田分公司,新疆 克拉玛依 834000;
    2.西安石油大学,陕西 西安 710065;
    3.陕西省油气成藏地质学重点实验室,陕西 西安 710065
  • 收稿日期:2020-06-03 修回日期:2021-01-09 出版日期:2021-04-25 发布日期:2022-02-16
  • 通讯作者: 赵靖舟(1962—),男,教授,1983年毕业于西北大学地质学专业,2002年毕业于中国石油勘探开发研究院矿产普查与勘探专业,获博士学位,现从事油气成藏地质学、非常规油气地质与勘探研究工作。
  • 作者简介:任海姣(1992—),女,助理工程师,2015年毕业于西安石油大学资源勘查工程专业,2019年毕业于该校矿产普查与勘探专业,获硕士学位,现从事油气成藏地质学研究工作。
  • 基金资助:
    陕西省教育厅重点科研计划项目“鄂尔多斯盆地中部奥陶系中组合天然气成藏富集规律研究”(2015JS094)

Key Controlling Factors of Natural Gas Accumulation in the Ordovician Ma Member 4 in the Central Ordos Basin

Ren Haijiao1,2, Wu Weitao2,3, Zhao Jingzhou2,3, Chen Mengna1   

  1. 1. PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China;
    2. Xi'an Shiyou University, Xi'an, Shaanxi 710065, China;
    3. Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi'an, Shaanxi 710065, China
  • Received:2020-06-03 Revised:2021-01-09 Online:2021-04-25 Published:2022-02-16

摘要: 鄂尔多斯盆地中部奥陶系马四段碳酸盐岩天然气具有一定的勘探潜力,但其天然气成藏主控因素尚不清楚,限制了该区勘探的深入,针对这一问题,利用钻井、测井、地球化学、试气等资料,分析奥陶系马四段天然气藏特征,从气源岩条件、储层特征、运移条件和遮挡条件等方面开展成藏主控因素研究。研究结果表明:马四段气藏类型主要为岩性气藏;气源岩条件控制着天然气的贫富,马四段天然气为上古生界煤系源岩和下古生界碳酸盐岩源岩生成的混合气,并以前者为主,由于气源条件不充足,整体产气量较少;储层特征导致天然气主要富集在物性中等的灰云坪相和云灰坪相;孔隙、裂缝与断层组成的三维网络系统为天然气运移提供通道;在灰岩遮挡条件控制下,天然气主要分布在厚层白云岩与灰岩岩性变化带以及厚层灰岩中部云质含量增加的部位。通过对马四段天然气成藏主控因素的认识,可为鄂尔多斯盆地海相碳酸盐岩勘探提供理论依据。

关键词: 天然气成藏, 主控因素, 气源条件, 碳酸盐岩, 沉积相, 海相沉积, 奥陶系马四段, 鄂尔多斯盆地

Abstract: There is certain potential of exploring the carbonate gas in the Ordovician Ma Member 4 in the Central Ordos Basin. However, the key controlling factors for natural gas accumulation are not clear, limiting the exploration in this area. In response to this problem, the gas reservoir characteristics of the Ordovician Ma Member 4 was analyzed with reference to drilling, logging, geochemistry, gas testing and other data. The key controlling factors of hydrocarbon accumulation were studied from the aspects of gas source rock conditions, reservoir characteristics, migration conditions, and shielding conditions. The results showed that the gas reservoirs of the Ordovician Ma Member 4 were mainly lithological gas reservoirs; the richness of natural gas was controlled by the gas-source rock conditions; the natural gas of the Ordovician Ma Member 4 was the gas mixture generated by the upper Paleozoic coal-bearing source rocks and the Lower Paleozoic carbonate source rocks, dominated by the former, and the overall gas produced was less due to insufficient gas source; the characteristics of the reservoir made the natural gas mainly accumulated in the lime dolomite flat facies and dolomite lime flat facies with medium physical properties; the three-dimensional network system composed of pores, fractures and faults provided channels for natural gas migration; under the control of limestone shielding conditions, the natural gas was mainly distributed in the section with lithologic change of thick dolomite and limestone, and the central section with increased dolomite content of thick limestone. The understanding of the key controlling factors of natural gas accumulation in the Ordovician Ma Member 4 can provide a theoretical foundation for the exploration of marine carbonate rocks in the Ordos Basin.

Key words: natural gas accumulation, key controlling factors, gas source conditions, carbonate rocks, sedimentary facies, marine facies, Ordovician Ma Member 4, Ordos Basin

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