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Articles 1141 - 1170 of 5558

Full-Text Articles in Oil, Gas, and Energy

Attenuation Model And Law Of High-Frequency Drilling Fluid Pressure Wave, Zhou Botao, Su Yinao, Wang Jiajin Sep 2023

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 …

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Magnetic Beacon-Based Horizontal Directional Drilling Guidance Technology, Zu Yutong, Wang Lu, Gong Da, Hu Yuanbiao Sep 2023

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 …

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Analysis On Motor Output Characteristics And Influencing Factors Of Oscillating Valve Mud Pulser, Qu Hanwu, Shang Jie, Lu Huatao, Wang Zhiming, Chen Kun Sep 2023

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 …

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Architecture Of Intelligent Service Platform For Drilling Based On Digital Twin, Jiang Jie, Huo Yuxiang, Zhang Haoxi, Yang Lanying, Tang Zhong, Li Qian Sep 2023

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 …

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Drilling Core Identification Based On Natural Image, Gao Hui, Wu Zhenkun, Ke Yu, Tan Songcheng, He Siqi, Duan Longchen Sep 2023

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 …

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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 Sep 2023

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 …

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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 Sep 2023

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 …

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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 Sep 2023

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 …

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Research Progress Of Intelligent Drilling Equipment And Technology, Zhang Xinxin, Liang Bowen, Zhang Xiaolong, Zhang Shaohe, Jin Xin Sep 2023

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 …

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Development And Prospect Of Intelligent Control Of Geological Drilling Process, Lu Chengda, Gan Chao, Chen Luefeng, Chen Xin, Cao Weihua, Wu Min Sep 2023

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 …

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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 Sep 2023

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 …

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Research On Coal-Rock Interface Recognition System Based On Drilling Parameters, Wang Jie Sep 2023

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. …

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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 Sep 2023

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 …

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Design Of Attitude Monitoring System For Directional Drilling Continuous Coring Tools, Lin Tingting, Liu Zekai, Ma Yinlong, Zhu Jinbao Sep 2023

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 …

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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 Sep 2023

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 …

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Bpop Prospectus, University Of North Dakota. Energy And Environmental Research Center Sep 2023

Bpop Prospectus, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Prospectus for Bakken Production Optimization Program (BPOP) 4.0.

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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 Aug 2023

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 …

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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 Aug 2023

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 …

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Table Of Contents, The Editors Aug 2023

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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R&D And Experimental Research Of Pressure-Preserved Triggering Device For Horizontal Pressure-Preserved Coring In Coal Mines, Huang Wei, Chen Ling, Li Jianan, Fan Dong, Yang Mingqing, Liu Guikang, Xu Qing, Ma Changliang Aug 2023

R&D And Experimental Research Of Pressure-Preserved Triggering Device For Horizontal Pressure-Preserved Coring In Coal Mines, Huang Wei, Chen Ling, Li Jianan, Fan Dong, Yang Mingqing, Liu Guikang, Xu Qing, Ma Changliang

Coal Geology & Exploration

Gas content is an important evaluation index of safe coal mining, as well as the exploitation and utilization of coalbed methane resources. Pressure-preserved coring is an effective way to improve the measurement accuracy of gas content in coal seams. Aiming at the special operating conditions of horizontal pressure-preserved coring in coal mines and based on the principle and technology of pressure- and gas-preserved coring in coal mines, this study developed a pressure-preserved triggering device and systematically designed the key components of the device, such as the sealing and pressure-preserved unit, the hydraulic drive module, and the salvager-unstuck mechanism between the …

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Principle And Technology Of In-Situ Magnetically Controlled Multidirectional Pressure-Preserved Coring In The Coal Mine, Liu Guikang, Li Cong, You Zhenxi, Hu Yunqi, Huang Wei, Wang Ruize, Xu Meng Aug 2023

Principle And Technology Of In-Situ Magnetically Controlled Multidirectional Pressure-Preserved Coring In The Coal Mine, Liu Guikang, Li Cong, You Zhenxi, Hu Yunqi, Huang Wei, Wang Ruize, Xu Meng

Coal Geology & Exploration

Obtaining the in-situ physical and mechanical parameters of coal-rock mass is the primary task for the development of deep coal resource. Accurate measurement of the in-situ parameters of gas is the basic guarantee to realize the safe mining of coal. In view of the technical challenges of inaccurate measurement of in-situ gas parameters in coal mine, the idea of multi-directional pressure-preserved coring technology based on magnetic force control was proposed with consideration to the technical characteristics of coring in underground coal mines. Specifically, a self-triggered magnetically controlled pressure-preserved controller was designed based on the characteristics of the composite magnetic field. …

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Simulation Optimization And Applications Of Pressure-Preserved Triggering Device For Coring In Deep Coal Mines, Shi Xiaojun, Li Minghui, Liu Guikang, You Zhenxi, Guo Lihua, Hou Lele, Zhao Xiang Aug 2023

Simulation Optimization And Applications Of Pressure-Preserved Triggering Device For Coring In Deep Coal Mines, Shi Xiaojun, Li Minghui, Liu Guikang, You Zhenxi, Guo Lihua, Hou Lele, Zhao Xiang

Coal Geology & Exploration

The pressure-preserved controller is the core component of pressure- and gas-preserved coring equipment used in deep coal mines. Its pressure-preserved capability and sealing performance are the key to pressure- and gas-preserved coring technology. Given that the existing pressure-preserved controller exhibits low initial sealing specific pressure and poor sealing performance when its initial sealing force is provided only by gravity, this study innovatively designed a pressure-preserved triggering device for coring, aiming to provide initial sealing specific pressure required for the sealing of the pressure-preserved controller. Then, this study conducted numerical simulations of the operating process of the triggering device using the …

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Development Of Self-Locking Transfer Mechanism For Coal Samples From Pressure-Preserved Coring In Deep Mining, Zhu Pengfei, Li Jianan, Li Ju, Fu Chenghang, Ye Banghua Aug 2023

Development Of Self-Locking Transfer Mechanism For Coal Samples From Pressure-Preserved Coring In Deep Mining, Zhu Pengfei, Li Jianan, Li Ju, Fu Chenghang, Ye Banghua

Coal Geology & Exploration

Pressure-preserved coring technology can directly store the collected deep coal samples at the bottom of the hole, so as to minimize the gas loss during the coring process. Besides, pressure transfer and testing of the pressure-preserved rock core is a technical prerequisite for the accurate determination of gas content. Then, how to achieve the precise docking from pressure-preserved coring to pressure transfer and testing has become a key technical difficulty that needs to be overcome urgently. Therefore, the research was carried out around the self-locking transfer mechanism, which is the core component of the docking transfer between the pressure-preserved coring …

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Closure Trajectory Model Of Pressure-Preserved Controller For Coring In Coal Seam Surface Well, Guo Da, Zhang Yiwei, Wang Dingming, Fang Xin, Yang Bengao, Guo Lihua, Hou Lele, Zhao Xiang Aug 2023

Closure Trajectory Model Of Pressure-Preserved Controller For Coring In Coal Seam Surface Well, Guo Da, Zhang Yiwei, Wang Dingming, Fang Xin, Yang Bengao, Guo Lihua, Hou Lele, Zhao Xiang

Coal Geology & Exploration

The traditional method of coal exploration is to obtain coal samples using an open coring tool and estimate the gas loss through theoretical calculations. However, the measured gas content of these coal samples is generally low, significantly impeding the development and utilization of coalbed methane and compromising the safety of coal mining operations. To meet the demands of deep coal exploration, an innovative pressure-preserved coring tool was specifically designed for the coal seam surface wells. This tool has a total length of 6.7 m and can extract a 3 m long pressure-preserved coal core sample at a single time. In …

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Fractal Theory-Based Permeability Model Of Fracture Networks In Coals, Xia Binwei, Liao Chuanbin, Luo Yafei, Ji Kainan Aug 2023

Fractal Theory-Based Permeability Model Of Fracture Networks In Coals, Xia Binwei, Liao Chuanbin, Luo Yafei, Ji Kainan

Coal Geology & Exploration

Fractures in coal reservoirs, which act as the major seepage pathways for coalbed methane (CBM), determine the permeability and CBM productivity of coal reservoirs. Research on the relationships between fracture structures and reservoir permeability is of great theoretical and practical significance for the accurate prediction of CBM productivity. Based on the classical cubic law-based permeability model, as well as the fractal theory, fracture network structures, and effective stress, this study built a permeability model containing complex bending fractures, which was then combined with the S & D (Shi-Durucan) model to build the permeability model of fractured coals under the action …

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A Method For Classification Of Surrounding Rock Based On The Excavatability Performance And Adaptability Of Tunnel Boring Machines And Its Applications, Liu Jiawei, Zhang Sheng, Chen Zhao, Yang Zhanbiao, Ji Panjun, Wei Yonghui Aug 2023

A Method For Classification Of Surrounding Rock Based On The Excavatability Performance And Adaptability Of Tunnel Boring Machines And Its Applications, Liu Jiawei, Zhang Sheng, Chen Zhao, Yang Zhanbiao, Ji Panjun, Wei Yonghui

Coal Geology & Exploration

The varying geological conditions of the surrounding rocks of coal mine roadways influence the wide application of full-face rock tunnel boring machines (TBMs). Therefore, accurately assessing the excavatability of rock masses in coal mines and the rock adaptability of TBMs is crucial for the efficient operation of TBMs. Based on the evaluation results of the parameters and excavatability of rock masses, this study built a classification model for rock mass excavatability using the technique for order preference by similarity to ideal solution (TOPSIS). Furthermore, combining the correlation analysis between the [BQ] values of different geological conditions and the utilization ratio …

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Drillability And Mechanical Parameters Of Laser Hot Cracking Sandstones, Yang Lei, Yang Bengao, Liu Junjun, Zhou Xuemin, Xie Jing, Wang Chen, Guo Chenchen, Gao Mingzhong Aug 2023

Drillability And Mechanical Parameters Of Laser Hot Cracking Sandstones, Yang Lei, Yang Bengao, Liu Junjun, Zhou Xuemin, Xie Jing, Wang Chen, Guo Chenchen, Gao Mingzhong

Coal Geology & Exploration

Over recent years, shallow coal resources that can be easily mined have been gradually exhausted. As a result, conventional drilling techniques tend to face challenges such as low rock-breaking efficiency, high drilling costs, and environmental pollution in the exploration and exploitation of deep coal resources. Therefore, there is an urgent need to introduce a new auxiliary rock-breaking technique for drilling. Focusing on the new laser-assisted rock-breaking technology, this study systematically conducted mechanical and drillability tests on sandstones after laser irradiation for different durations, aiming to explore the temporal and spatial evolution of the temperature field of hard sandstones, the propagation …

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Physical And Mechanical Properties Of Thermal Insulation Materials For In-Situ Temperature-Preserved Coring Of Deep Rocks, Xue Shouning, He Zhiqiang, Li Cong, Yu Bo, Lu Xuelian, Liu Wenyue, Yang Jianping, Wei Zijie Aug 2023

Physical And Mechanical Properties Of Thermal Insulation Materials For In-Situ Temperature-Preserved Coring Of Deep Rocks, Xue Shouning, He Zhiqiang, Li Cong, Yu Bo, Lu Xuelian, Liu Wenyue, Yang Jianping, Wei Zijie

Coal Geology & Exploration

High temperature affects deep coal mining and other engineering activities. However, conventional coring methods for terrestrial hard rocks lack temperature-preserved measures, ignoring the effects of temperature on the physical and mechanical properties of rocks. Consequently, the parameters obtained are subjected to distortion, affecting the safe and efficient mining of resources such as deep coals. To make breakthroughs in the development of in-situ temperature-preserved coring technologies for deep rocks, this study proposed using the hollow glass microsphere/epoxy resin (HGM/EP) as thermal insulation materials and the physical and mechanical properties. The results are as follows: (1) With an increase in the HGM …

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Sealing Performance Analysis And Structure Optimization Of Pressure-Preserved Controller For Pressure-Preserved Coring In Deep Coal Mine, Wang Tianyu, Li Jianan, Zhang Yiwei, Li Ju, Xie Heping Aug 2023

Sealing Performance Analysis And Structure Optimization Of Pressure-Preserved Controller For Pressure-Preserved Coring In Deep Coal Mine, Wang Tianyu, Li Jianan, Zhang Yiwei, Li Ju, Xie Heping

Coal Geology & Exploration

As the pressure-preserved controller is a core component of the deep coal in-situ pressure-preserved coring device, its sealing design plays a decisive role in the effect of pressure-preserved coring. In order to obtain the optimal sealing structure, a two-dimensional axisymmetric nonlinear contact model was established for the sealing structure of the pressure-preserved controller. On this basis, the effects of different groove design, cone angle selection and friction coefficient on the sealing performance were analyzed by orthogonal test method. Meanwhile, the stress changes of the sealing ring under different closing stages and medium pressures were studied. The results show that: the …

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Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong Aug 2023

Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong

Coal Geology & Exploration

The in-situ gas pressure and content of coal seams are critical for the safe production of deep coal mines and the accurate evaluation of coalbed methane resources. To address the technical challenges of accurately determining in-situ gas content in deep coal seams, this study proposed brand-new principles of in-situ pressure coring and the tests of in-situ gas content and pressure. It also derived a calculation method for in-situ gas content in coal seams and a method for determining the in-situ gas pressure while considering the effects of moisture content and multiple gas components. Given the in-situ stress environment deep in …

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