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Articles 781 - 810 of 2083
Full-Text Articles in Earth Sciences
Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing
Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing
Coal Geology & Exploration
As the weathered bedrock and burned rock aquifers seriously threaten the production safety of mines in the Jurassic coalfield of northern Shaanxi Province, accurate prediction of their waterrichness and water inflow at the working face is of great significance for water control in mines. Aiming at the weathered bedrock and burned rock aquifers with close hydraulic connection, the area where working face 15217 of Shaanxi Hongliulin Coal Mine is located was taken as the study area. Meanwhile, the aquifer thickness, lithological combination index, index of rock burning and weathering degree and core recovery was taken as the evaluation indexes. The …
Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang
Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang
Coal Geology & Exploration
In order to reveal the mechanism of two-region Darcian and non-Darcian flow induced by constant-head pumping tests in unconfined aquifers, a numerical model of well flow by constant-head pumping underground based on finite difference solution was proposed. In the model, it is assumed that the aquifer is divided into two regions according to the pumping flow characteristics: the finite non-Darcian flow region near the pumping well and the semi-infinite Darcian flow region far away from the pumping well. Specifically, the flow regime in the non-Darcian flow region was simulated by the Izbash’s equation, and the reliability of the proposed solution …
Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin
Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin
Coal Geology & Exploration
To study the mesoscopic failure characteristics of the layered red shale, uniaxial mechanical experiments were carried out by applying DSTD-1000 electro-hydraulic servo rigid pressure on the red shale with different bedding angles. Meanwhile, SEM and XRD experiments were implemented on debris to obtain its mechanical parameters, failure characteristics, microstructure, and relative content of components. Based on this, models of the red shale with different bedding angles were constructed using the discrete element PFC3D for the uniaxial compression experiments to study the mesoscopic failure characteristics of red shale. The results show that: (1) When the bedding angle θ=30°, 45°, …
Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun
Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun
Coal Geology & Exploration
In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces. However, coal seams, which have viscoelasticity actually, imposing absorptive and attenuation effects on in-seam waves. To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media, this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation. Using this equation, three-dimensional finite-difference numerical simulation was carried out. The results indicate that (1) for reflected in-seam waves in viscoelastic media, which exhibit high energy attenuation, their propagation and attenuation characteristics are …
Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang
Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang
Coal Geology & Exploration
In order to improve the support efficiency of coal mine roadway and the automation intelligence of heading face, an anchor drilling robot integrating the cantilever roadheader and the six-degree-of-freedom manipulator was designed, and studied on the anchor drilling sequence planning strategy and the drilling boom trajectory planning method. Firstly, the kinematics model of the manipulator structure was established based on the improved DH method. On this basis, the forward and inverse kinematics solutions were analyzed, and the spatial position and the corresponding joint variable values of the drilling rig were calculated. Secondly, the manipulator space was analyzed based on Monte …
More Than Energy: Coal As A Mineral Resource, University Of North Dakota. Energy And Environmental Research Center
More Than Energy: Coal As A Mineral Resource, University Of North Dakota. Energy And Environmental Research Center
EERC Brochures and Fact Sheets
Brochure on Carbon Ore, Rare Earth, and Critical Minerals (CORE-CM) Initiative, an Energy & Environmental Research Center and U.S. Department of Energy project. Explores the benefits of utilizing lignite coal from the Williston Basin.
Research On Three-Stage Automatic Hole Packer For Gas Extraction Drilling In Underground Coal Mine, Wang Qingfeng, Shi Shuhan, Xin Dezhong, Chen Hang, Zhang Shitao
Research On Three-Stage Automatic Hole Packer For Gas Extraction Drilling In Underground Coal Mine, Wang Qingfeng, Shi Shuhan, Xin Dezhong, Chen Hang, Zhang Shitao
Coal Geology & Exploration
In view of the requirements of hole sealing during gas extraction drilling in underground coal mine for manual packer installation and sealing material injection, as well as the low automation level of hole sealing technology, a three-stage automatic hole packer for gas extraction drilling in underground coal mine was developed, with the appearance similar to the drill pipe. The hole packer could be mechanized into the drilling hole by an automatic drilling machine, and realize the automatic injection of sealing material. Herein, the Mooney-Rivlin hyperelastic constitutive model was used to represent the strain energy function by the finite element analysis …
Intelligent Optimization And Control Technology For Drilling Process Of Coal Mine Tunnels, Yao Ningping, Wu Min, Chen Luefeng, Lu Chengda, Fan Haipeng, Zhang Youzhen, Li Wangnian, Yao Ke
Intelligent Optimization And Control Technology For Drilling Process Of Coal Mine Tunnels, Yao Ningping, Wu Min, Chen Luefeng, Lu Chengda, Fan Haipeng, Zhang Youzhen, Li Wangnian, Yao Ke
Coal Geology & Exploration
The harsh environment for drilling construction of coal mine tunnel, complex coal seam structure and complicated operation procedures can cause low drilling efficiency and high drilling cost. For this reason, it is imperative to carry out studies on the optimization and control technology for the drilling process of coal mine tunnel. Herein, study was conducted from intelligent identification of lithology of coal-bearing formation, intelligent optimization of drilling parameters and their intelligent control, focusing on the key technology for control of drilling process of coal mine tunnel. First, in order to accurately determine the type of coal-bearing formation, an intelligent identification …
Continuous And Discontinuous Numerical Simulation Of The Rock Breaking Process Of Pdc Drill Bit Under Composite Impact, Qin Chengshuai, Sun Hongbin, Li Liping, Liu Xuegang, Liu Zhihui, Feng Chun, Sun Zizheng
Continuous And Discontinuous Numerical Simulation Of The Rock Breaking Process Of Pdc Drill Bit Under Composite Impact, Qin Chengshuai, Sun Hongbin, Li Liping, Liu Xuegang, Liu Zhihui, Feng Chun, Sun Zizheng
Coal Geology & Exploration
Composite impact drilling is a novel rock-breaking technique that combines both axial and torsional impacts. To address the issues of complex failure mechanisms and unclear rock-breaking mechanisms under the axial-torsional impacts on rock by Polycrystalline Diamond Compact (PDC) drill bits, a FEM-DEM rock model based on shared nodes was established using the Continuous Discontinuous Element Method (CDEM), and the rationality of this computational model was verified through laboratory uniaxial compression experiments. Besides, a composite impact motion model for single drill bit was built through the secondary development of JavaScript, and the composite impact rock-breaking process of single PDC drill bit …
Application Of Intelligent Direct Push Measurement While Drilling Device For Environmental Geological Surveys, Sun Pinghe, Zhou Shengwei, Cao Han, Gao Qiang, Cheng Gongbi, Zhang Hui
Application Of Intelligent Direct Push Measurement While Drilling Device For Environmental Geological Surveys, Sun Pinghe, Zhou Shengwei, Cao Han, Gao Qiang, Cheng Gongbi, Zhang Hui
Coal Geology & Exploration
In order to solve the technical challenges of inaccuracy and poor credibility of contaminant survey results due to the low accuracy of drilling trajectories in environmental geological surveys, the structural and functional characteristics of the existing direct-push drilling tools were analyzed. On this basis, the method of near-bit measurement while drilling using single-action combination was proposed. An intelligent measurement-while-drilling (MWD) device was developed, a laboratory platform monitoring module was established, a set of monitoring software was developed, and the stability and reliability of the intelligent MWD device was analysed. Then, verification tests have been carried out on the laboratory platforms …
Wear Law And Design Of Assembling Diamond Bit Based On Finite Element Analysis, Yang Zhan, Tan Songcheng, Yang Kaihua, Fang Xiaohong
Wear Law And Design Of Assembling Diamond Bit Based On Finite Element Analysis, Yang Zhan, Tan Songcheng, Yang Kaihua, Fang Xiaohong
Coal Geology & Exploration
In addition to coring drilling, full (non-coring) drilling also occupies a large proportion in the energy exploration and development. Non-coring drilling can reduce the high time cost of lifting and lowering work required for coring, thereby increasing the net drilling time, improving the drilling efficiency and reducing the drilling costs. The traditional non-coring drill bits are prone to uneven wear on the bit surface during the drilling process. To identify and improve this law of uneven wear, it was herein proposed to use the assembling non-coring bit to improve the eccentric wear of bit. For this reason, numerical simulation analysis …
Table Of Contents, The Editors
Attenuation Model And Law Of High-Frequency Drilling Fluid Pressure Wave, Zhou Botao, Su Yinao, Wang Jiajin
Attenuation Model And Law Of High-Frequency Drilling Fluid Pressure Wave, Zhou Botao, Su Yinao, Wang Jiajin
Coal Geology & Exploration
The technology of transmitting high-frequency drilling fluid pressure wave information with high transmission rate. It is also one of the key technologies to achieve the automated and intelligent drilling. However, the field application of this technology is hindered by the substantial attenuation experienced by high-frequency drilling fluid pressure waves during the transmission process. Thus, exploring the attenuation characteristics of these waves is crucial for the development of high-speed transmission technology. Herein, it is assumed that the drilling fluid pressure is equivalent on the same section of drill string, and the flow rate of drilling fluid is radially distributed. On this …
Magnetic Beacon-Based Horizontal Directional Drilling Guidance Technology, Zu Yutong, Wang Lu, Gong Da, Hu Yuanbiao
Magnetic Beacon-Based Horizontal Directional Drilling Guidance Technology, Zu Yutong, Wang Lu, Gong Da, Hu Yuanbiao
Coal Geology & Exploration
In order to solve the problems of existing horizontal directional drilling (HDD) guidance methods, including low measurement accuracy, shallow positioning distance, discontinuous measurement data and great interference by magnetic field, a magnetic beacon-based horizontal directional drilling guidance and positioning method was proposed to achieve the position and attitude measurement of HDD. Meanwhile, a measurement array based on the third-order magnetic gradient tensor was designed, which verifies through simulation that the method could eliminate the influence of the geomagnetic fields and achieve the position measurement. In order to improve the attitude measurement accuracy, the multisource data fusion was performed with MEMS …
Analysis On Motor Output Characteristics And Influencing Factors Of Oscillating Valve Mud Pulser, Qu Hanwu, Shang Jie, Lu Huatao, Wang Zhiming, Chen Kun
Analysis On Motor Output Characteristics And Influencing Factors Of Oscillating Valve Mud Pulser, Qu Hanwu, Shang Jie, Lu Huatao, Wang Zhiming, Chen Kun
Coal Geology & Exploration
The oscillating valve pulser is a better choice for high-speed mud pulse transmission due to its capability of generating a higher frequency carrier. Great difficulties are brought to the research on the motor output characteristics due to the complex load moment and its numerous influencing factors during the operation. Using the dynamic balance equation for the motor operating in underground coal mine, the position angle and output current data of the oscillating valve motor under the Max Torque per Ampere (MTPA) control mode were obtained by measurement in the water cycle experiment. Then, the output torque and output power of …
Architecture Of Intelligent Service Platform For Drilling Based On Digital Twin, Jiang Jie, Huo Yuxiang, Zhang Haoxi, Yang Lanying, Tang Zhong, Li Qian
Architecture Of Intelligent Service Platform For Drilling Based On Digital Twin, Jiang Jie, Huo Yuxiang, Zhang Haoxi, Yang Lanying, Tang Zhong, Li Qian
Coal Geology & Exploration
In view of the situation of unknown, complex and variable drilling objects and frequent drilling accidents during the geological drilling, a digital twin model system of geological drilling based on time series data was built with the digital twin technology, so as to meet the actual requirements of prediction while drilling, condition identification, drilling rate optimization and others. The monitored data of ground equipment, measurement-while-drilling and drilling process were decomposed into prior data, real-time data, delayed data and late data according to the time series. On this basis, these multi-source heterogeneous data were processed by the Internet of Things, characteristic …
Drilling Core Identification Based On Natural Image, Gao Hui, Wu Zhenkun, Ke Yu, Tan Songcheng, He Siqi, Duan Longchen
Drilling Core Identification Based On Natural Image, Gao Hui, Wu Zhenkun, Ke Yu, Tan Songcheng, He Siqi, Duan Longchen
Coal Geology & Exploration
The traditional on-site core identification and recording mainly rely on the experience of technicians, and there are many uncertain factors. Limited by the site conditions, using mobile phones or cameras to capture the natural images is the most convenient way to collect the core information. Therefore, it is necessary to study the feature information extraction technology of core image and apply it to the identification and prediction of core type and other information. Specifically, a large number of core samples were collected, the thin-section identification method was employed to determine the core types and names, and then the core images …
An Intelligent Prediction Method And Interpretability For Drag And Torque Of Drill String, Liu Muchen, Song Xianzhi, Li Dayu, Zhu Shuo, Fu Li, Zhu Zhaopeng, Zhang Chengkai, Pan Tao
An Intelligent Prediction Method And Interpretability For Drag And Torque Of Drill String, Liu Muchen, Song Xianzhi, Li Dayu, Zhu Shuo, Fu Li, Zhu Zhaopeng, Zhang Chengkai, Pan Tao
Coal Geology & Exploration
The accurate characterization and dynamic analysis of drilling string mechanics are essential to ensure the safe and efficient drilling. In the classical soft/rigid string model for drag & torque of drilling string, the friction coefficient of the drilling string is determined by empirical estimation or post-drilling inversion, of which the accuracy and timeliness needs to be improved. Based on the effectiveness of artificial intelligence technology applied in complex nonlinear mapping, a drag and torque prediction method of drill string with mechanism-data fusion was proposed by predicting the friction coefficient. Firstly, the friction coefficient was inversed using the drilled and logged …
Development Of Remote Service Platform For Underground Tunnel Drilling Rigs Of Coal Mine, Liu Shijie, Yan Bin, Yao Ke, Dai Chenyu, Guan Zhiyang, Wang Longpeng, Li Jian, Zhu Qianxiang
Development Of Remote Service Platform For Underground Tunnel Drilling Rigs Of Coal Mine, Liu Shijie, Yan Bin, Yao Ke, Dai Chenyu, Guan Zhiyang, Wang Longpeng, Li Jian, Zhu Qianxiang
Coal Geology & Exploration
In view of the large demand for personnel in the underground coal mine drilling site, many potential safety hazards, and the difficulty of controlling the movement of the drilling rig by one-man operation and knowing the operating status of the drilling rig from a global perspective, the digital twin technology has benn introduced to design and develop a remote service platform for the drilling rig. Based on the ZDY25000LDK drilling rig, the platform system integrates the technologies concerning the remote control system of the drilling rig, the digital twin model and parameter monitoring system, with the remote control of the …
Research Progress Of Intelligent Drilling Equipment And Technology, Zhang Xinxin, Liang Bowen, Zhang Xiaolong, Zhang Shaohe, Jin Xin
Research Progress Of Intelligent Drilling Equipment And Technology, Zhang Xinxin, Liang Bowen, Zhang Xiaolong, Zhang Shaohe, Jin Xin
Coal Geology & Exploration
For the development and utilization of complex marine and continental oil and gas resources, and some problems of heterogeneity and uncertainty inevitably encountered during the drilling under complex geological conditions, it is urgent to create opportunities for the development of intelligent drilling technology and equipment using the high-end information such as artificial intelligence, big data and machine learning. Herein, the intelligent drilling system and its basic components were described, mainly including the field surface intelligent control platform, the data measurement communication control network system, the downhole intelligent steering drilling system and the remote real-time intelligent control center system. Besides, the …
Development And Prospect Of Intelligent Control Of Geological Drilling Process, Lu Chengda, Gan Chao, Chen Luefeng, Chen Xin, Cao Weihua, Wu Min
Development And Prospect Of Intelligent Control Of Geological Drilling Process, Lu Chengda, Gan Chao, Chen Luefeng, Chen Xin, Cao Weihua, Wu Min
Coal Geology & Exploration
The complex and ever-changing geological environment and harsh conditions pose enormous challenges to the control of geological drilling process. The flourishing development of frontier technologies such as big data and artificial intelligence has brought new opportunities to the development of drilling industry. Firstly, the development status of intelligent control of geological drilling process is elaborated from 3 aspects: Sensing and modelling of drilling process, intelligent optimization of drilling process and drilling process control. In terms of sensing and modelling of drilling process, various geological environment models have been established using multi-source information of drilling process, which enables the sensing of …
Intelligent Lithology Prediction Method Based On Vibration Signal While Drilling And Deep Learning, Wang Sheng, Lai Kun, Zhang Zheng, Bai Jun, Luo Zhongbin, Li Bingle, Zhang Jie
Intelligent Lithology Prediction Method Based On Vibration Signal While Drilling And Deep Learning, Wang Sheng, Lai Kun, Zhang Zheng, Bai Jun, Luo Zhongbin, Li Bingle, Zhang Jie
Coal Geology & Exploration
Intelligent lithology prediction is of great importance in geological drilling, capable of improving exploration and mining efficiency, as well as the quality of results. In this study, a method of intelligent lithology prediction while drilling was proposed based on the vibration signals produced by the drill bit breaking rocks during drilling. Specifically, seven types of rocks with the same size and different lithologies were selected, and a micro-drilling experiment was designed to apply different drilling rates and rotary speeds to the rocks, in order to collect the triaxial vibration signals while drilling under multiple drilling conditions. The signals were preprocessed …
Research On Coal-Rock Interface Recognition System Based On Drilling Parameters, Wang Jie
Research On Coal-Rock Interface Recognition System Based On Drilling Parameters, Wang Jie
Coal Geology & Exploration
In response to the problems of untimely and inaccurate coal-rock interface recognition and lack of appropriate technical means during the construction of cross-seam drilling for gas drainage by bottom drainage roadway, a coal-rock interface recognition system based on drilling parameters (rotational speed, rotary torque, propulsion force, advance velocity, crushing work ratio) was developed. The entire system consists of a data sensing layer, a data acquisition layer and a data analysis layer. Among them, the data sensing layer and the data acquisition layer are also collectively called the drilling data acquisition system, which can collect the drilling parameters in real time. …
Prediction Of Crack Width Of Drilling Fluid Leakage Based On Neural Network, Wang Jian, Xu Jiafang, Zhao Mifu, Wang Bowen, Wang Yahua, Chen Jie, Wang Xiaohui, Yang Gang, Ma Tengfei
Prediction Of Crack Width Of Drilling Fluid Leakage Based On Neural Network, Wang Jian, Xu Jiafang, Zhao Mifu, Wang Bowen, Wang Yahua, Chen Jie, Wang Xiaohui, Yang Gang, Ma Tengfei
Coal Geology & Exploration
During the drilling, it is difficult to select the appropriate leakage prevention and plugging methods and materials as the development of reservoir fractures is unknown. Herein, a reservoir crack width prediction method based on neural network was proposed with reference to the actual history data of wells. Firstly, the main influencing factors of reservoir fracture width were explored and ranked by correlation analysis, and seven main influencing factors, including pump pressure, drilling fluid displacement and drilling speed, were selected as the input parameters. The rate of convergence of the model was improved using the additional momentum algorithm and the variable …
Design Of Attitude Monitoring System For Directional Drilling Continuous Coring Tools, Lin Tingting, Liu Zekai, Ma Yinlong, Zhu Jinbao
Design Of Attitude Monitoring System For Directional Drilling Continuous Coring Tools, Lin Tingting, Liu Zekai, Ma Yinlong, Zhu Jinbao
Coal Geology & Exploration
Directional drilling continuous coring, as an emerging geological exploration technique, holds vast potential in the field of mineral resource exploration. To facilitate the development of directional continuous coring tools with proprietary intellectual property rights, an attitude monitoring system based on attitude sensing and wireless communication technology was designed in this paper. Concerning the hardware system design, the MPU9250 attitude sensor and STM32F103C8T6 main control chip were adopted to monitor the attitude change of drilling tools, where the communication through geological layers was achieved using a LoRa wireless module. Additionally, to accommodate the structural of the drilling tool and the requirements …
Tracking Control Of Drilling Robot Feed Force Based On An Equivalent-Input-Disturbance, Li Wangnian, Lu Chengda, Zhang Youzhen, Song Haitao, Tian Shengnan, Huang Hengyu, Chen Luefeng, Wu Min
Tracking Control Of Drilling Robot Feed Force Based On An Equivalent-Input-Disturbance, Li Wangnian, Lu Chengda, Zhang Youzhen, Song Haitao, Tian Shengnan, Huang Hengyu, Chen Luefeng, Wu Min
Coal Geology & Exploration
During the underground construction of gas extraction hole in coal mine, the feeding system of drilling robot is used for pressurization, decompression and feeding in drilling process. In view of the problem that the uncertain disturbance of complex strata affects the working performance of drilling robot and the quality and efficiency of drilling construction, the structural composition and drilling construction technology of drilling robot were analyzed at first. The mathematical model of pressure reducing valve control was established according to the working principle of its feed system, and the mapping relationship between the control input, the electromagnet current, and the …
Research Status And Development Trend Of Near-Bit Mwd In Underground Coal Mine, Hao Shijun, Chu Zhiwei, Li Quanxin, Fang Jun, Chen Long, Liu Jianlin
Research Status And Development Trend Of Near-Bit Mwd In Underground Coal Mine, Hao Shijun, Chu Zhiwei, Li Quanxin, Fang Jun, Chen Long, Liu Jianlin
Coal Geology & Exploration
Near-bit meusurement while drilling (MWD) integrates several key technologies such as near-bit multi-parameter measurement, power supply and communication across positive displacement motor drills, turbine continuous power generation and high-speed mud pulse wireless transmission, capable of obtaining various types of parameters near the bit. It is one of the key components of intelligent drilling technology in underground coal mine. Herein, the limitation of the existing technology applied in coal mine was analyzed with full reference to the development experience and development path of near-bit MWD in the field of surface oil and gas drilling. Meanwhile, the research idea of near-bit MWD …
Mining-Induced Shear Deformation And Permeability Evolution Law Of Crushed Rock Mass In Fault Zone, Li Qiang, Ma Dan, Zhang Jixiong, Liu Yong, Hou Wentao
Mining-Induced Shear Deformation And Permeability Evolution Law Of Crushed Rock Mass In Fault Zone, Li Qiang, Ma Dan, Zhang Jixiong, Liu Yong, Hou Wentao
Coal Geology & Exploration
To explore the mechanism of water inrush induced by fault activation under mining, experimental studies were conducted on the shear deformation and permeability evolution of crushed rock mass in fault zone. Specifically, a set of compression-shear-seepage test system for crushed rock mass was designed according to the principle of fluid-solid coupling, with the coupling process of shear deformation and seepage realized. On this basis, the shear-seepage coupling test was carried out for the crushed rock mass under the influence of multiple factors. Thus, the influence of particle size distribution and initial porosity of crushed rock mass on porosity and permeability …
Stimulation Effect Of Pulsed Ultrasonic Excitation On Coal Pores With Full-Scale Pore Sizes, Lin Haifei, Qiu Yue, Han Shuangze, Gao Haidong, Yang Erhao, Wang Ruizhe, Yan Min
Stimulation Effect Of Pulsed Ultrasonic Excitation On Coal Pores With Full-Scale Pore Sizes, Lin Haifei, Qiu Yue, Han Shuangze, Gao Haidong, Yang Erhao, Wang Ruizhe, Yan Min
Coal Geology & Exploration
This study aims to further investigate the stimulation effect of pulsed ultrasonic excitation on coal pore structures. Using an ultrasonic excitation test system for gas-containing coals, this study conducted ultrasonic excitation tests on coals under continuous and interactive pulses with ultrasonic power of 800 W and 1000 W. Through low-pressure CO2 adsorption tests, low-temperature nitrogen adsorption tests, and the mercury injection capillary pressure (MICP) tests, this study explored the evolutionary patterns of parameters of various coal pores with full-scale pore sizes, including macropores (> 50 nm), mesopores (2‒50 nm), and micropores (< 2 nm). The test results are as follows: (1) Pulsed ultrasonic waves can expand coal pores. The pore volume of coals was primarily provided by micropores and macropores, with mesopores representing a small proportion. The specific surface area of various coal pores was in the order of micropores > mesopores > macropores. (2) Compared with those having …
Table Of Contents, The Editors