石油学报 ›› 2019, Vol. 40 ›› Issue (10): 1192-1201.DOI: 10.7623/syxb201910005

• 地质勘探 • 上一篇    下一篇

川南地区龙马溪组页岩岩相对页岩孔隙空间的控制

王曦蒙, 刘洛夫, 汪洋, 盛悦, 郑珊珊, 罗泽华   

  1. 中国石油大学(北京)地球科学学院 油气资源与探测国家重点实验室 北京 102249
  • 收稿日期:2019-03-01 修回日期:2019-05-26 出版日期:2019-10-25 发布日期:2019-11-09
  • 通讯作者: 刘洛夫,男,1958年11月生,1982年获江汉石油学院学士学位,1992年获英国布里斯托大学博士学位,现为中国石油大学(北京)教授,主要从事石油地质及油气地球化学研究。Email:liulf@cup.edu.cn
  • 作者简介:王曦蒙,男,1994年11月生,2017年获中国石油大学(北京)资源勘查工程专业学士学位,现为中国石油大学(北京)地质资源与地质工程专业硕士研究生,主要从事页岩储层特征及页岩气成藏机理研究。Email:913649441@qq.com
  • 基金资助:

    国家科技重大专项(2017ZX05035-002-005)资助。

Control of lithofacies on pore space of shale from Longmaxi Formation, southern Sichuan Basin

Wang Ximeng, Liu Luofu, Wang Yang, Sheng Yue, Zheng Shanshan, Luo Zehua   

  1. College of Geosciences, China University of Petroleum;State Key Laboratory of Petroleum Resources and Prospecting, Beijing 102249, China
  • Received:2019-03-01 Revised:2019-05-26 Online:2019-10-25 Published:2019-11-09

摘要:

页岩的孔隙类型、孔隙结构的定量化表征以及孔隙空间的控制因素是页岩储层研究的重要问题。川南地区龙马溪组的页岩岩相按矿物组分可分为硅质页岩、混合质页岩和黏土质页岩。利用扫描电镜矿物定量评价(QEMSCAN)技术、低温N2和CO2吸附实验以及高压压汞实验对川南地区龙马溪组不同页岩岩相的孔隙类型、结构特征及孔隙空间的控制因素开展了分析。研究结果表明,黏土质页岩多发育黏土矿物片状粒内孔且多被迁移有机质充填;混合质页岩多发育有机质孔和碳酸盐矿物溶蚀宏孔;硅质页岩多发育有机质孔。页岩的总面孔率主要由孔径为0~500 nm的孔隙提供,矿物(除碳酸盐矿物与长石外)及有机质中的孔隙均以粒内孔为主,有机质的面孔率高达32.37%,为矿物颗粒的8~16倍。页岩的中孔是孔体积的主要贡献者,微孔是孔比表面积的主要贡献者。混合质页岩的总面孔率、孔体积与孔比表面积的平均值与硅质页岩相近,具有良好的储集能力。高TOC含量的混合质页岩与硅质页岩的孔隙空间主要受有机质孔控制,TOC含量较低的黏土质页岩的孔隙空间则主要受有机质孔和伊利石相关孔隙共同控制。

关键词: 龙马溪组, 页岩岩相, 孔隙类型, 面孔率, 孔隙结构, 有机质孔

Abstract:

The pore types of shale, quantitative characterization of pore structures and control factors of pore spaces are important topics in research of shale reservoir. The shale lithofacies of Longmaxi Formation in the southern Sichuan Basin can be classified into siliceous shale, mixed shale and argillaceous shale according to the mineral composition. The pore types, structural characteristics and control factors of pore spaces of different shale lithofacies of Longmaxi Formation in the southern Sichuan Basin were analyzed by technologies of quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN), low temperature N2 and CO2 adsorption and high pressure mercury intrusion experiments. The results show that the argillaceous shale is mostly characterized by the sheet-like intragranular pores of clay minerals and filled with the migrated organic matters; the mixed shale is rich in organic matter pores and carbonate dissolved macropores; siliceous shale is rich in organic matter pores. The total surface porosities of shale is mainly provided by the pores with the diameter of 0-500 nm. The surface porosity of minerals (except carbonate and feldspar)and organic matters are mainly contributed by intragranular pores. The surface porosity of organic matter is up to 32.37%, 8 to 16 times higher than that of mineral particles. The mesopores of shale are the main contributors to the pore volume, while micropores make a major contribution to the specific surface area of pores. The average surface porosity, pore volume and pore specific surface area of mixed shale are similar to those of siliceous shale, which means the mixed shale has potential storage capacity. The pore space of mixed shale and siliceous shale with high TOC content is mainly controlled by organic matter pores, but the pore space of argillaceous shale with lower TOC content is mainly controlled by organic matter pores and illite mineral related pores.

Key words: Longmaxi Formation, shale lithofacies, pore type, surface porosity, pore structure, organic matter pore

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