Acta Petrolei Sinica ›› 2019, Vol. 40 ›› Issue (9): 1030-1044.DOI: 10.7623/syxb201909002

• Petroleum Exploration • Previous Articles     Next Articles

Development characteristics of organic pore in the continental shale and its genetic mechanism: a case study of Shahezi Formation shale in the Changling fault depression of Songliao Basin

Gao Fenglin1,2, Song Yan1,2,3, Liang Zhikai1,2, Li Zhuo1,2, Yuan Yuan4, Zhang Yinghan1,2, Chen Lei1,2, Guo Wang5   

  1. 1. State Key Laboratory of Petroleum Resources and Prospecting, Beijing 102249, China;
    2. Unconventional Oil and Gas Institute, China University of Petroleum, Beijing 102249, China;
    3. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China;
    4. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
    5. Xi'an Center, China Geological Survey, Shaanxi Xi'an 710054, China
  • Received:2019-01-29 Revised:2019-05-21 Online:2019-09-25 Published:2019-10-15

陆相页岩有机质孔隙发育特征及成因——以松辽盆地长岭断陷沙河子组页岩为例

高凤琳1,2, 宋岩1,2,3, 梁志凯1,2, 李卓1,2, 原园4, 张瀛涵1,2, 陈磊1,2, 郭望5   

  1. 1. 油气资源与探测国家重点实验室 北京 102249;
    2. 中国石油大学非常规油气科学技术研究院 北京 102249;
    3. 中国石油勘探开发研究院 北京 100083;
    4. 中国科学院地质与地球物理研究所 北京 100029;
    5. 中国地质调查局西安地质调查中心 陕西西安 710054
  • 通讯作者: 宋岩,女,1957年10月生,1982年获华东石油学院石油地质专业学士学位,2003年获中国科学院博士学位,现为中国石油大学(北京)非常规油气科学技术研究院教授,主要从事天然气地质综合研究工作。Email:sya@petrochina.com.cn
  • 作者简介:高凤琳,女,1988年3月生,2010年获西安石油大学地质学专业学士学位,2014年获中国地质大学(北京)矿物学、岩石学、矿床学专业硕士学位,现为中国石油大学(北京)非常规油气科学技术研究院博士研究生,主要从事非常规天然气成藏与地质评价的研究工作。Email:471568216@qq.com
  • 基金资助:

    国家科技重大专项(2016ZX05034-001-005)和国家自然科学基金项目(No.41602162)资助。

Abstract:

Organic pores in the continental shale show a relatively strong heterogeneity. Taking the Shahezi Formation shale in the Changling fault depression of Songliao Basin as an example, and based on observation using the field emission scanning electron microscopy and optical microscopy, this paper explores the heterogeneity characteristics and genetic mechanism of organic pores in the continental shale. The results show that there are four main factors controlling the heterogeneity of organic matters in the continental shale, i.e., remnants of primary organic pores, differences in hydrocarbon generation potential, differences in the solid bitumen reflectance and catalyses of clay minerals. Due to the fact that the cell lumens were not filled or subjected to external force, the components with higher plant fiber structure, such as telinite, fusinite, semi-fusinite and sclerotinite, formed the fold superimposed with residual pores. Pores are best developed in solid bitumen, followed by vitrinite and intertinite; the weight percentage of carbon in the three components increases successively, indicating that the difference in pore development among the three organic matters is essentially controlled by the difference in the hydrocarbon generation potential. Not all of the organic pores are developed in solid bitumen. Statistics show that the porous solid bitumen mostly has the reflectivity of 1.60% -2.00%, in the stage of petroleum cracking and gas generation; the non-porous solid bitumen mostly has the reflectance of 1.20% -1.60%, in the stage of kerogen cracking and hydrocarbon generation. Under the catalyses of clay minerals, almost all solid bitumens in the organoclay complex are developed with rich honeycomb pores. The specific catalytic activity can be enhanced by illite, thus facilitating the formation of gaseous hydrocarbon and the generation of pores.

Key words: pore heterogeneity, organic pores, maceral, Shahezi Formation shale, Songliao Basin

摘要:

陆相页岩有机质孔隙的非均质性强。以松辽盆地长岭断陷沙河子组页岩为例,通过场发射扫描电镜与偏光显微镜的定位观察,探讨了陆相页岩有机质孔隙的非均质特征及成因机理。研究结果表明,控制陆相页岩有机质孔隙非均质性的主要因素有4种:原生有机质孔隙残余、生烃潜力差异、固体沥青反射率差异以及黏土矿物催化作用。结构镜质体、丝质体、半丝质体以及少量菌落体等具有高等植物纤维结构的组分,因细胞腔未被充填或受外力作用褶曲叠覆可残留孔隙。固体沥青中孔隙发育最好,其次为镜质体和惰质体;三者的碳元素重量百分比依次增大,表明这3种有机质中孔隙发育程度的差异本质上受生烃潜力差异控制。不是所有的固体沥青中都发育有机质孔隙。统计显示,多孔固体沥青的反射率多为1.60%~2.00%,处于石油裂解生气阶段,而无孔固体沥青的反射率多为1.20%~1.60%,处于干酪根裂解生烃阶段。黏土矿物的催化作用使得有机黏土复合体中几乎所有的固体沥青均发育丰富的蜂窝状孔隙,伊利石的存在可增加比催化活度,导致气态烃更易生成并产生孔隙。

关键词: 孔隙非均质性, 有机质孔隙, 显微组分, 沙河子组页岩, 松辽盆地

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