Article
Engineering, Geological
H. J. Lu, H. P. Xie, Y. Luo, L. Ren, R. Zhang, C. B. Li, J. Wang, M. Q. Yang
Summary: The study conducted direct shear tests on shale samples with different bedding orientations and found significant anisotropies in the shear stress-displacement relation, failure patterns, and shear strength. The new anisotropic shear failure criterion proposed in the study showed good agreement with the test results, indicating that the maximum shear strength in shale varies with the applied normal stress.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Chemical
Guanzheng Qu, Tao Shi, Zheng Zhang, Jian Su, Haitao Wei, Rui Guo, Jiao Peng, Kairui Zhao
Summary: This study aims to describe the surface morphology characteristics of shale fractures and proposes a set of methods for characterization. The study found that these characteristics are directional and positively correlated with roughness.
Article
Engineering, Geological
Mateusz Maslowski, Malgorzata Labus
Summary: This paper presents experiments on proppant embedment phenomenon on shale rock from the Baltic Basin, an unconventional gas deposit region. The results show that proper selection of proppant and fracturing fluid can reduce fracture width and increase conductivity. The novel laboratory imaging procedure introduced in the article is a valuable method for assessing the vulnerability of reservoir rocks to embedment.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Geological
L. Ren, H. P. Xie, X. Sun, R. Zhang, C. B. Li, J. Xie, Z. T. Zhang
Summary: The study investigates the fracture properties of Lower Silurian Longmaxi shale by conducting three-point bend tests in three principal fracture orientations. The results show the critical shape coefficient depends on the anisotropic elasticity of the investigated shale, and using a critical shape coefficient for isotropic rock could lead to a maximum error in the calculated fracture toughness. Additionally, the mode I fracture toughness varies across different fracture orientations, with a progressive decrease in fracture energy observed.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Sam S. Hashemi, Mark D. Zoback
Summary: The experimental study found that supercritical carbon dioxide (scCO(2)) has an impact on fracture permeability and surface characteristics in shales of various compositions, especially in samples with high carbonate content. Permeability may increase and fracture surface may degrade with longer exposure time. The sensitivity of permeability to effective normal stress also increases as the fracture surface becomes more compliant after exposure to scCO(2).
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Mechanics
Xiaoming Wang, Junbin Chen, Dazhong Ren, Jianhong Zhu
Summary: This study classified typical natural fractures in the Chang 7 reservoir of the Yanchang Formation using Fullbore Microscan Imager (FMI) and geostatistics. The results showed that natural fractures with different topology structures have different impacts on hydraulic fracture propagation. Among them, natural fractures with type II nodes have the largest effect, with the longest and fastest propagation velocity, leading to the most complex fracture network.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Geosciences, Multidisciplinary
Shaoqiang Yang, Dong Yang, Zhiqin Kang
Summary: This study investigates the mechanical properties and morphology changes of oil shale at different temperatures through tensile experiments. It reveals that temperature has a significant effect on tensile strength and fracture types of oil shale. Results show a decrease in tensile strength below 400 degrees C, with a multiple fracture type observed in this temperature range. Above 400 degrees C, a shift in tensile strength values and fracture types is observed.
NATURAL RESOURCES RESEARCH
(2021)
Article
Construction & Building Technology
Dongshuai Hou, Wei Zhang, Zhi Ge, Pan Wang, Xinpeng Wang, Hongzhi Zhang
Summary: The study implemented the Peridynamics theory on the fracture performance modelling of mortar at the meso-scale, showing that the PD theory can predict the load-displacement response and crack pattern satisfactorily without further calibration.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Mechanics
Cunbao Li, Dongchao Yang, Heping Xie, Li Ren, Jun Wang
Summary: Studying the anisotropic fracture behavior of shale is crucial for evaluating the development of a stimulated reservoir volume. The fracture toughness decreases with increasing bedding dip angle, reaching maximum and minimum values at 0 degrees and 90 degrees, respectively, with a ratio of 1.60. The crack propagates along the bedding plane when the dip angle is higher than 45 degrees.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Energy & Fuels
Rui Zhou, Zihan Sun, Tianyu Chen, Zhiming Hu, Kaijia Zhang, Mingguang Che
Summary: Understanding the permeability changes in shale under shear displacement is crucial for the development of unconventional gas or oil sources. Previous studies mainly focused on experiments under low-stress conditions, leaving the mechanism behind the permeability change in the presence of high effective stress unclear. This study used numerical models and laboratory experiments to investigate the dynamic permeability changes in shale with rough fracture surfaces. The morphology of internal fractures induced by different shear deformations was also examined. The results provide new insights into the permeability evolution of rock strata under shear action.
Article
Energy & Fuels
Shibin Li, Kai Liang, Changhao Wang, Yuxuan Jiao, Hegao Liu, Chunhua Wang
Summary: This study established a wellbore stability model for layered shale based on experimentally measured anisotropic elasticity and strength parameters. The results showed that considering anisotropy, the collapse pressure is the largest, and the influence of strength anisotropy is greater than that of elastic anisotropy. Horizontal wells have the best stability, and the actual drilling conditions of G101 well were consistent with the predicted results.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Engineering, Geological
Q. Zhou, H. P. Xie, Z. M. Zhu, R. He, H. J. Lu, Z. D. Fan, X. F. Nie, L. Ren
Summary: Insight into the anisotropic fracture properties of shale under high in situ stress is given through a series of hydraulic fracturing tests on double wing crack specimens of Longmaxi shale. The study finds that the fracture resistance of shale significantly increases with confining pressure, and both fracture toughness and fracture energy exhibit remarkable anisotropies. The study also highlights the influence of in situ stress on shale fracture anisotropy, which should be carefully considered in hydraulic fracturing design.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Energy & Fuels
Zhipeng Huo, Jianbo Gao, Jinchuan Zhang, Dong Zhang, Yutao Liang
Summary: Limestones play a crucial role in the natural hydraulic fracturing of shale sections, aiding in selecting fracturing locations, enhancing stimulation power, and clarifying fracture propagation law to maximize shale oil and gas production.
Article
Energy & Fuels
Yushi Zou, Shicheng Zhang, Xinfang Ma, Xiaohuan Zhang, Shipeng Zhang
Summary: This study finds that continental shale oil formations are more complex and heterogeneous than marine shale formations. The presence of dense laminas, lithologic interfaces, and mineral-filled natural fractures in these formations can create complex hydraulic fracture growth, proppant placement, and conductivity evolution mechanisms. The findings provide important insights for the implementation of hydraulic fracturing.
Article
Geosciences, Multidisciplinary
Siwei Meng, Dongxu Li, Qi Wang, Jiaping Tao, Jian Su, Hanqi Li, Xu Jin, Liu Yang
Summary: A new comprehensive evaluation method for shale fracturing was developed in this study, utilizing multiple factors and nanoindentation to determine fracturing and fracability coefficients that assess the overall fracturing performance of shale. The results were found to be consistent with actual performance.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Thermodynamics
Jianming He, Xiao Li, Chao Yin, Yixiang Zhang, Chong Lin
Article
Energy & Fuels
Cheng Cheng, Xiao Li, Nengxiong Xu, Bo Zheng
Article
Energy & Fuels
Y. T. Duan, X. Li, P. G. Ranjith, Y. F. Wu
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2020)
Article
Chemistry, Multidisciplinary
Xiaohui Liao, Qi Ouyang, Haiyang Liu, Juanjuan Sun, Xueliang Wang, Lihui Li, Zhifa Yang, Zigan Chen
APPLIED SCIENCES-BASEL
(2020)
Article
Energy & Fuels
Lihui Li, Beixiu Huang, Xiaolin Huang, Ming Wang, Xiao Li
Article
Energy & Fuels
Shuhui Zhang, Xiao Li, Quanchen Gao, Erchao Li, Tongde Zhao, Xinyao Wang
PETROLEUM SCIENCE AND TECHNOLOGY
(2020)
Article
Geosciences, Multidisciplinary
Tianming Huang, Zhenbin Li, Bernhard Mayer, Michael Nightingale, Xiao Li, Guanfang Li, Yin Long, Zhonghe Pang
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Engineering, Geological
Xiukuo Sun, Xiao Li, Bo Zheng, Jianming He, Tianqiao Mao
ENGINEERING GEOLOGY
(2020)
Article
Geosciences, Multidisciplinary
Lihui Li, Beixiu Huang, Yufang Tan, Xiao Li, P. G. Ranjith
Summary: In this study, the elastic modulus differences of laminae in continental shale were investigated using micro-indentation technique and SEM. The results show that the elastic moduli of laminae are highly heterogeneous and can be classified into three types: the stiffer layer, the intermediate layer, and the soft layer. Additionally, the elastic modulus of lamina excellently correlates with mineral compositions. By analyzing the thickness and elastic modulus of each individual lamina, the elastic modulus of shale can be obtained. This provides a rapid and economically feasible method for studying the mechanical properties of shale.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Chemistry, Physical
Lihui Li, Chenglong Li, Beixiu Huang, Ming Wang, Zhida Bai, Shengwen Qi
Summary: The study found that, despite similar mineral composition and porosity, the mechanical properties of strongly welded tuffs are significantly better than those of weakly welded tuffs, with different failure modes as well.
Proceedings Paper
Computer Science, Information Systems
Shouding Li, Jialiang Zhang, Siyuan Wu, Weichang Chen, Dong Chen, Xiao Li, Han Wang
INFORMATION TECHNOLOGY IN GEO-ENGINEERING
(2020)
Article
Energy & Fuels
Yanzhi Hu, Xiao Li, Zhaobin Zhang, Jianming He, Guanfang Li
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2020)