Article
Engineering, Geological
Long-Chuan Deng, Xiao-Zhao Li, Wentao Xu, Liang Qiao, Peng Zhao
Summary: Understanding the relationship between drilling response parameters and rock properties is useful for quickly obtaining lithology parameters and dynamically grasping drilling conditions. This study designed a small-scale core drilling platform to simulate drilling in different types of rocks. Mechanical sensors were developed to monitor drilling response parameters. Experimental results showed that torque and axial thrust force were positively correlated with rock strength, while drilling speed was negatively correlated with rock strength. Conversely, axial thrust force and torque were negatively correlated with brittleness, while drilling speed was positively correlated with brittleness. The drilling speed was uniform for homogeneous lithology.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Haoteng Wang, Mingming He, Jianbin Zhao, Yonghao Zhang, Beibei Yang
Summary: This study proposes a new method for evaluating rock brittleness using a digital drilling approach, which includes a cutting model to describe the relationship between energy characteristics and mechanical parameters. A drilling-based index, the brittleness evaluation index (BEI), was developed based on energy dissipation. Drilling tests were conducted to investigate energy evolution, and the results indicated a linear correlation between cutting energy and rock strength parameters. Our proposed method provides a reliable evaluation of rock brittleness compared to the laboratory-determined brittleness index.
ENGINEERING GEOLOGY
(2023)
Article
Multidisciplinary Sciences
Mustafa Emre Yetkin
Summary: The study aims to examine and analyze the drilling operation and its duration in underground ore and dead rock by conducting drillability experiments on core samples. The results show that production galleries and holes formed parallel to bedding would increase production efficiency. Additionally, it is found that drilling speed increases steadily to a maximum point in the first 5 seconds and then remains stable, indicating the importance of drilling direction in enhancing efficiency.
ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS
(2021)
Article
Energy & Fuels
Wei -Ji Liu, Yan-Fei Wang, Zhao-Wang Dan, Xiao-Hua Zhu
Summary: In this study, the impact rock breaking experiments using different types of PDC cutters were conducted to investigate the influence of parameters such as cutter shape, rake angle, and impact energy on rock-breaking. The results showed that the conical-shaped cutter had the highest breaking efficiency and the penetration depth was mainly influenced by the impact energy and cutter shape. The research findings provide reference and basis for improving the rock-breaking efficiency in deep hard formations.
Article
Energy & Fuels
Ming-Zhong Gao, Ben-Gao Yang, Jing Xie, Si-Qi Ye, Jun-Jun Liu, Yi-Ting Liu, Rui-Feng Tang, Hai-Chun Hao, Xuan Wang, Xiang-Yue Wen, Xue-Min Zhou
Summary: This study focuses on the new microwave rock-breaking technology and conducts experimental and numerical simulation research on typical deep, hard rock granite. The research results show that granite exhibits high-temperature melting and fracture in the microwave field, with temperatures reaching up to 550°C. The numerical simulation results demonstrate the interaction of thermal stress and in situ stress, leading to the separation of the rock stratum into different areas.
Article
Geochemistry & Geophysics
Tianbin Li, Zhile Shu, Xin Zhang, Meiben Gao, Huangsong Pan
Summary: This study focuses on the thermomechanical (TM) coupling effects of rock bursts in regions with high geothermal and geostresses. Various tests were conducted to analyze the brittleness and rock burst mechanism under TM conditions. The research revealed that higher temperatures led to increased brittleness and rock burst tendency, with more intense and earlier failure occurring. This study has significant academic value and practical significance for the prevention, design, and safe construction of rock bursts in deep high geothermal tunnels.
Article
Chemistry, Multidisciplinary
Xiaopeng Yue, Tao Wen, Yuan Gao, Wenjun Jia, Yankun Wang, Mingyi Hu
Summary: The assessment of rock brittleness is crucial for understanding the mechanical properties and engineering behavior of rocks. This study summarizes existing evaluation methods and proposes a new brittleness index. The research findings provide guidance for evaluating and understanding the brittleness variations of red-bed sandstone and cyan sandstone.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Geological
Xiao-Ping Zhang, Xin-Mei Yang, Wei-Qiang Xie, Quan-Sheng Liu, Shao-hui Tang
Summary: The macro-indentation test is commonly used for evaluating rock mechanical properties, and various indentation indices have been proposed. In this study, previous studies on indentation indices were summarized, and indentation tests were conducted on 47 granite specimens to calculate 26 indices. The indices generally concentrate around the mean value and have different dispersion degrees. Force indices and energy indices show high correlation, while force indices and modulus indices have little correlation. Most modulus indices are correlated, while most dimensionless indices are independent. For highly correlated indices, those with low dispersion are preferred. Proper indices for estimating rock strength, representing rock brittleness, and drillability are suggested based on their distribution characteristics, correlations, and prediction accuracy. The minimum testing number to achieve the required accuracy is also proposed for these selected indices.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Review
Engineering, Geological
Fanzhen Meng, Louis Ngai Yuen Wong, Hui Zhou
Summary: The research reviewed various definitions of rock brittleness and identified 80 brittleness indices, showing a lack of standardization in the measurement methods. It was found that different field-specific indices are not directly applicable to others, and some empirically-obtained indices may not truly reflect rock brittleness.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2021)
Article
Energy & Fuels
Guozhou Qiu, Xin Chang, Jing Li, Yintong Guo, Lei Wang, Hongling Ma, Wuhao Guo, Zhenhui Bi
Summary: The brittleness characteristics of deep volcanic rocks were studied through triaxial compression tests and XRD tests. The results showed that the brittleness index of volcanic rocks decreased with the increase in confining pressure, and deep volcanic rocks exhibited lower brittleness. Additionally, an improved brittleness evaluation method based on internal friction Angle was proposed, and its evaluation results were consistent with the results obtained by other two methods.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2023)
Article
Engineering, Marine
Xingchen Li, Liang Xiong, Wenwei Xie, Ke Gao, Yutao Shao, Yunlong Chen, Yanjiang Yu, Beibei Kou, Qiuping Lu, Jing Zeng, Haoyu Yu
Summary: The hard rock stratum in deep-sea drilling negatively impacts efficiency and increases costs. Three different core bits, namely roller bit, diamond bit, and bionic bit, were designed and tested. Results showed that the roller bit provided stable drilling, low torque, and high efficiency in hard rock stratum. The new formula diamond bit demonstrated good adaptability to changing hard rock strata, with an average rate of penetration of 4.4 m/h and a bit life of 137.75 m. The bionic bit achieved a 100% core recovery rate, with an average rate of penetration of 1.35 m/h and a maximum rate of 1.88 m/h. The design and experiment of these three drill bits effectively solved the technical problem of efficient drilling in deep-sea hard-rock stratum.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Environmental
Utku Sakiz, Hamit Aydin, Olgay Yarali
Summary: This study investigates the impact of operational machine parameters and rock properties on drilling performance parameters for rotary core drilling conditions. The experiments reveal a strong inverse relationship between specific drilling energy and penetration rate, and a strong correlation between specific energy (470 rpm and 70 kg load) and rock sample properties. The optimal drilling performance is achieved when the penetration rate reaches 1 m/h.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Geological
Wei Wang, Yu Wang, Bo Chai, Juan Du, Linxiao Xing, Ziheng Xia
Summary: Accurate evaluations of rock brittleness are crucial in the fields of engineering geology and geotechnical engineering. Previous studies have focused on stress-strain relationships to estimate rock brittleness but overlooked rock damage. This study proposed a new brittleness index (BI23) considering rock damage, which was calculated using an energy-based method. The validation results showed that the rock brittleness estimated by BI23 significantly decreased under increasing confining pressures and temperatures. A comparative study demonstrated that BI23 produced more stable and consistent rock brittleness, even for the same rock type under different tests, representing a major improvement over previous indices. The distribution patterns of brittleness values for normal and extreme conditions were also discussed.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Chunjiang Zou, Suo Yingying, Kai Liu, Yi Cheng, Jianchun Li
Summary: With the development of 3D printing and computer numerical control machining techniques, researchers have been able to conduct complex experiments to simulate underground rock structures. This study compares artificial materials with natural marble to investigate their brittleness behavior and assess the feasibility of physical simulation. The study also explores the influence of strain rate on brittleness under dynamic loading conditions and proposes two brittleness indexes to evaluate the behavior of dynamic gypsum.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Computer Science, Information Systems
Bosong Yu, Kai Zhang, Ganggang Niu
Summary: This research studied two real-time rock strength determination models based on drilling parameters using a discrete element model, providing a method for simulating rock behavior. The applicability of rock drillability index and drilling specific energy in rock strength assessment was investigated, with results showing that the rock drillability index is more accurate than drilling specific energy.
