Pore Structure Characteristics of Shale Oil Reservoirs with Different Lithofacies and Their Effects on Mobility of Movable Fluids: A Case Study of the Chang 7 Member in the Ordos Basin, China

被引:1
|
作者
Xiao, Yufang [1 ,2 ,3 ]
Ye, Zhengqin [4 ]
Wang, Hongliang [1 ,2 ,3 ]
Yang, Hailong [4 ]
Mu, Nana [1 ,2 ,3 ]
Ji, Xinyuan [5 ]
Zhao, He [1 ,2 ,3 ]
机构
[1] China Univ Geosci, Sch Energy Resources, Beijing 100083, Peoples R China
[2] China Univ Geosci Beijing, Key Lab Marine Reservoir Evolut & Hydrocarbon Acc, Minist Educ, Beijing 100083, Peoples R China
[3] China Univ Geosci, Beijing Key Lab Unconvent Nat Gas Geol Evaluat & D, Beijing 100083, Peoples R China
[4] Yanchang Oilfield Co Ltd, Yanan 716000, Peoples R China
[5] China Natl Offshore Oil Corp Ltd, Tianjin Branch, Tianjin 300459, Peoples R China
基金
中国国家自然科学基金;
关键词
pore size distribution; movable fluid distribution; Chang; 7; member; shale oil reservoirs; Ordos Basin; NUCLEAR-MAGNETIC-RESONANCE; TIGHT SANDSTONE RESERVOIRS; TRIASSIC YANCHANG FORMATION; THROAT STRUCTURE; PERMEABILITY; MINERALOGY; AREA; GAS;
D O I
10.3390/en17040862
中图分类号
TE [石油、天然气工业]; TK [能源与动力工程];
学科分类号
0807 ; 0820 ;
摘要
The Chang 7 member of the Triassic Yanchang Formation in the Ordos Basin is a significant continent shale oil reservoir in China. Therefore, conducting an in-depth investigation into the pore structure and fluid mobility characteristics of the Chang 7 shale oil reservoir holds immense importance for advancing shale oil exploration. This study conducts a detailed analysis of the pore structures and their impact on fluid mobility of the Chang 7 shale oil reservoir using multiple methodologies, i.e., a cast thin section, scanning electron microscopy (SEM), X-ray diffraction (XRD), high-pressure mercury injection (HPMI), low-temperature nitrogen adsorption (LTNA), and nuclear magnetic resonance (NMR). The results show that the sandstone in the Yanwumao area of the Chang 7 shale oil reservoir consists mainly of lithic arkose and feldspathic litharenite, which can be classified into three lithofacies (massive fine-grained sandstone (Sfm), silt-fine sandstone with graded bedding (Sfgb), and silt-fine sandstone with parallel bedding (Sfp)). Moreover, three pore structures (Type I, II, and III), and four pore spaces (nanopores, micropores, mesopores, and macropores) can be characterized. Pore structure Type I, characterized by large pores, exhibits bimodal pore diameter curves, resulting in the highest levels of movable fluid saturation (MFS) and movable fluid porosity (MFP). Pore structure Type II demonstrates unimodal pore structures, indicating robust connectivity, and higher MFS and MFP. Pore structure Type III primarily consists of dissolved and intercrystalline pores with smaller pore radii, a weaker pore configuration relationship, and the least fluid mobility. Furthermore, a correlation analysis suggests that the pore structure significantly impacts the fluid flowability in the reservoir. Favorable petrophysical properties and large pores enhance fluid flowability. Micropores and mesopores with high fractal dimensions have a greater impact on reservoir fluid mobility compared to macropores and nanopores. Mesopores mainly control MFS and MFP, while micropores govern the shift from bound fluid to movable fluid states. Among the lithofacies types, the Sfm lithofacies exhibit the highest fluid mobility due to their significant proportion of macropores and mesopores, whereas the Sfgb lithofacies have lower values because they contain an abundance of micropores. The Sfp lithofacies also dominate macropores and mesopores, resulting in medium fluid mobility levels. This study combines lithofacies types, micro-reservoir pore structure characteristics, and mobile fluid occurrence characteristics to better understand the dominant reservoir distribution characteristics of the Chang 7 shale oil reservoirs in the Ordos Basin and provide theoretical information for further optimization of production strategies.
引用
收藏
页数:20
相关论文
共 50 条
  • [31] The Effect of Hydration on Pores of Shale Oil Reservoirs in the Third Submember of the Triassic Chang 7 Member in Southern Ordos Basin
    Zhao, Pengfei
    Fan, Xiangyu
    Zhang, Qiangui
    Wang, Xiang
    Zhang, Mingming
    Ran, Jiawei
    Lv, Da
    Liu, Jinhua
    Shuai, Juntian
    Wu, Hao
    ENERGIES, 2019, 12 (20)
  • [32] Sedimentary features of the gravity flow influenced shale deposit: A case study of Chang 7 member in the Ordos Basin, China
    Hou, Lianhua
    Pang, Zhenglian
    Luo, Xia
    Lin, Senhu
    MARINE AND PETROLEUM GEOLOGY, 2023, 153
  • [33] Occurrence Characteristics of Chang 7 Shale Oil from the Longdong Area in the Ordos Basin: Insights from Petrology and Pore Structure
    Fan, Yunpeng
    Zhang, Zhanyu
    Zhou, Xinping
    Zhang, Kun
    Wen, Zhigang
    Tian, Weichao
    Gao, Heting
    Yang, Yuxuan
    Liu, Yuhang
    Zheng, Xiaoyin
    PROCESSES, 2023, 11 (11)
  • [34] Spontaneous Imbibition Characteristics and Influencing Factors of Chang 7 Shale Oil Reservoirs in Longdong Area, Ordos Basin
    Zhou X.
    Chen D.
    Xia Y.
    Zeng J.
    Qiao J.
    Xu X.
    Cai J.
    Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences, 2022, 47 (08): : 3045 - 3055
  • [35] Shale oil exploration potential in central Ordos Basin: A case study of Chang 7 lacustrine shale
    Fan B.
    Jin Y.
    Shi L.
    Li Y.
    Chen W.
    Oil and Gas Geology, 2021, 42 (05): : 1078 - 1088
  • [36] Study on evolution mechanism of the pyrolysis of chang 7 oil shale from Ordos basin in China
    Jiang, Haiyan
    Liu, Shuai
    Wang, Jiao
    You, Yuan
    Yuan, Shibao
    ENERGY, 2023, 272
  • [37] Nanoscale pore structure and fractal characteristics of the continental Yanchang Formation Chang 7 shale in the southwestern Ordos Basin, central China
    Ju, Wei
    You, Yuan
    Chen, Yilin
    Feng, Shengbin
    Xu, Haoran
    Zhao, Yue
    Liu, Bo
    ENERGY SCIENCE & ENGINEERING, 2019, 7 (04): : 1188 - 1200
  • [38] STUDY ON THE CORRELATION BETWEEN OCCURRENCE CHARACTERISTICS OF MOVABLE FLUIDS AND MICROSCOPIC PORE STRUCTURE OF CHANG 8 FORMATION RESERVOIR IN CENTRAL ORDOS BASIN
    Liu, Bobiao
    Tan, Chengqian
    Li, Rongxi
    Chen, Shoumin
    Yang, Guobin
    Hou, Jingtao
    Tan, Yuhan
    Li, Delu
    Huai, Yinchao
    FRESENIUS ENVIRONMENTAL BULLETIN, 2019, 28 (4A): : 3131 - 3140
  • [39] Geological characteristics and exploration of shale oil in Chang 7 Member of Triassic Yanchang Formation, Ordos Basin, NW China附视频
    FU Jinhua
    LI Shixiang
    NIU Xiaobing
    DENG Xiuqin
    ZHOU Xinping
    Petroleum Exploration and Development, 2020, (05) : 931 - 945
  • [40] Characteristics and Genesis of Collophane in Organic-Rich Shale of Chang 7 Member in Ordos Basin, North China
    Zhang, Yu
    Dai, Chaocheng
    Bian, Congsheng
    Bai, Bin
    Jiang, Xingfu
    MINERALS, 2024, 14 (12)