Acta Petrolei Sinica ›› 2019, Vol. 40 ›› Issue (1): 74-85.DOI: 10.7623/syxb201901006

• Oil Field Development • Previous Articles     Next Articles

Influence of laminar structure differences on the fracability of lacustrine fine-grained sedimentary rocks

Xiong Zhouhai1, Cao Yingchang1,2, Wang Guanmin1,2, Liang Chao1, Shi Xiaoming1, Li Mingpeng3, Fu Yao4, Zhao Shouqiang5   

  1. 1. School of Geosciences, China University of Petroleum, Shandong Qingdao 266580, China;
    2. Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Shandong Qingdao 266071, China;
    3. Petrochina Research Institute of Petroleum Exploration and Development, Beijing 100083, China;
    4. Baishan Seismostation, Jilin Baishan 134300, China;
    5. Qingdao Jiahang Petroleum Technology Company Limited, Shandong Qingdao 266590, China
  • Received:2018-04-19 Revised:2018-09-18 Online:2019-01-25 Published:2019-01-29

湖相细粒沉积岩纹层结构差异对可压裂性的影响

熊周海1, 操应长1,2, 王冠民1,2, 梁超1, 石晓明1, 李明鹏3, 付尧4, 赵寿强5   

  1. 1. 中国石油大学地球科学与技术学院 山东青岛 266580;
    2. 海洋国家实验室海洋矿产资源评价与探测技术功能实验室 山东青岛 266071;
    3. 中国石油勘探开发研究院 北京 100083;
    4. 白山市地震台 吉林白山 134300;
    5. 青岛嘉航石油科技有限公司 山东青岛 266590
  • 通讯作者: 王冠民,男,1969年4月生,1991年获长春地质学院地质学专业学士学位,2005年获中国科学院广州地球化学研究所矿物学、岩石学、矿床学专业博士学位,现为中国石油大学(华东)教授、博士生导师,主要从事石油地质与勘探研究。Email:wguanmin@sina.com
  • 作者简介:熊周海,男,1990年1月生,2013年获中国石油大学(华东)资源勘查工程专业学士学位,2017年获中国石油大学(华东)地质学硕士学位,现为中国石油大学(华东)地质学博士研究生,主要从事页岩油气勘探开发工作。Email:xiongzhouhai@126.com
  • 基金资助:

    国家自然科学基金项目(No.41572123和U1762217),国家科技重大专项(2016ZX05024-003和2016ZX05006-003),山东省自然科学基金项目(ZR2014DM013),国家自然科学基金青年科学基金项目(No.41602142)和中国石油大学(华东)研究生创新基金项目(18CX06022A)资助。

Abstract:

Laminar structures of fine-grained sedimentary rocks (e.g., laminar development degree, thickness, thickness difference and continuity) are intrinsic factors affecting the mechanical properties of rocks and crack propagation. Taking the Mesozoic-Cenozoic lacustrine fine-grained sedimentary rocks of Eastern China as an example, the corresponding relationship between different laminar structures and mechanics parameters of rocks is analyzed based on the conventional triaxial test and fracture toughness experiment in combination with image analysis and processing technology. Meanwhile, this paper comprehensively evaluates the influence of the laminar structure difference of lacustrine fine-grained sedimentary rocks on the fracability. The results show that the fracability index of fine-grained sedimentary rocks is negatively correlated with the quantity and continuity of laminae, while positively correlated with the laminar thickness variance and the vertical distribution variance of grains. The developed fine-grained sedimentary rocks with strong continuity show excellent plasticity. The compressive fractures are mainly extended along the lamina interface or the laminae with certain plasticity (e.g., clay lamina or organic lamina), easy to close again in the fine-grained sedimentary rocks, thus reducing the fracability of rock. The fine-grained sedimentary rocks with large difference in thickness and high homogeneity of laminar vertical distribution have high brittleness, which is beneficial to the development of complex and effective mesh fractures in fracturing process, thus improving the fracability of rocks. In addition, the composition, particle texture and diagenesis of fine-grained sedimentary rocks also play an important role in controlling the fracability.

Key words: laminar structure, fine-grained sedimentary rocks, fracability, continuity, controlling mechanism

摘要:

细粒沉积岩纹层结构(如纹层发育程度、厚度大小、厚度差异性和连续度)是影响岩石力学性质以及裂缝扩展的内在因素。通过对中国东部中生代-新生代的湖相细粒沉积岩开展研究,以常规三轴实验和断裂韧性实验为基础,结合图像分析和处理技术,分析了不同纹层结构与岩石力学参数之间的对应关系,综合评价了湖相细粒沉积岩纹层结构差异对可压裂性的影响。研究表明,细粒沉积岩的可压裂性指数与纹层数量、连续度呈负相关,但与纹层厚度方差、颗粒垂向分布方差呈正相关。纹层发育且连续性强的细粒沉积岩,其塑性较强,压裂缝以沿纹层界面或塑性纹层(黏土纹层或有机质纹层)扩展为主,裂缝易再次闭合,从而导致岩石的可压裂性降低。纹层厚度差异性较大、颗粒垂向分布均匀度较高的细粒沉积岩,其脆性较高,在压裂过程中易形成复杂有效的网状缝,从而提高岩石的可压裂性。此外,细粒沉积岩组分、颗粒结构以及成岩作用对可压裂性也具有重要的控制作用。

关键词: 纹层结构, 细粒沉积岩, 可压裂性, 连续性, 控制机理

CLC Number: