High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam, Chen Dongdong, Wang Jianli, Jia Bingyi, Xi Jie
Coal Geology & Exploration
Advanced management of gas enrichment area is an important guarantee to realize safe, efficient and intelligent mining in coal mine. Aiming at the problem of high-efficiency gas drainage in broken and soft coal seam region, taking No.3 coal seam in Hancheng mining area as the research object, a gas drainage mode of comb-shaped long borehole hydraulic fracturing in the roof of coal seam is proposed. The applicability of the model is verified by means of theoretical analysis, numerical simulation and field test, and the fracture propagation law, gas drainage mechanism, and fracturing curve features of comb-shaped borehole in adjacent roof …
Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane,
2022
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China
Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane, Li Quangui, Wu Xiaobin, Hu Qianting, Liu Le, Shi Jialin, Song Mingyang
Coal Geology & Exploration
The structural plane extensively occurs in coal measures, and is one of the key factors affecting the hydraulic fracturing effect of coal/rock. The fabrication time and filling material types of the structural plane were adjusted to obtain the coal/rock specimens without the filling structural plane, or the coal/rock specimens with the filling structural plane. The physical experiment for hydraulic fracturing was carried out to find out the effect and action mechanism of the structural plane type and injected flow rate on hydraulic fracture extension. As indicated by the result, in the condition of the injected flow rate of 50 mL/min, …
Analysis And Prospect Of Precise Prevention And Control Technical System Ahead Of Large Areas And Time For Gas Disasters In China,
2022
State Key Laboratory of the Gas Disaster Detecting, Preventing and Emergency Controlling, Chongqing 400037, China; China Coal Technology and Engineering Group Chongqing Research Institute, Chongqing 400039, China
Analysis And Prospect Of Precise Prevention And Control Technical System Ahead Of Large Areas And Time For Gas Disasters In China, Liu Cheng, Sun Dongling, Wu Wenbin, Li Liangwei, Sun Zhongguang
Coal Geology & Exploration
To meet the rapid development of coal mine automation and intelligent production and the urgent need for rapid prevention and regional management outburst, and to promote the development of the gas disaster control technology system in large areas of coal mines, this paper aims to solve the problem of traditional coal seam drilling gas drainage technology, which is “not deep enough to be drilled and cannot be pumped out and cannot be tested.” It analyzes the application effects of technical equipment such as directional drilling, surface wells, staged hydraulic fracturing, deep hole sampling, and detection while drilling in various geological …
Hydrochemical Characteristics And Source Analysis Of Deep Groundwater In Qianyingzi Coal Mine,
2022
School of Earth and Environment, Anhui University of Science & Technology, Huainan 232001, China
Hydrochemical Characteristics And Source Analysis Of Deep Groundwater In Qianyingzi Coal Mine, Chen Kai, Liu Qimeng, Liu Yu, Peng Weihua, Wang Zitao, Zhao Xiang
Coal Geology & Exploration
The shallow coal resources in China have been gradually depleted. Under the condition that the deep coal exploitation has been started, the threat from the high-artesian limestone water at the coal seam floor is greater. Deep understanding of the hydrochemical composition control mechanism in the aquifer of the mine area is an important scientific precondition for pertinently carrying out water hazard prevention and control. In order to find out the qualitative and quantitative sources of the conventional ions which in the deep ground water of the Anhui Qianyingzi Coal Mine, the 22 conventional ion concentrations in limestone water were analyzed …
Abnormal Response Characteristic Simulation During Transient Electromagnetic Detection In Mine Borehole,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Abnormal Response Characteristic Simulation During Transient Electromagnetic Detection In Mine Borehole, Zhang Jun
Coal Geology & Exploration
Conventional mine transient electromagnetic advance detection method is greatly influenced by the condition outside of the mine, which leads to the inaccurate location in anomalous body detection. In order to solve this problem, an advance detection method for measuring the three-component signals of the transient electromagnetic field in the down-hole borehole was proposed to carry out numerical simulation for the abnormal response characteristics from the different locations of the plane where the receiving coil is located and the different orientations of the anomalous body. The principle of borehole transient electromagnetic detection was analyzed, and the test design and construction design …
Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes,
2022
Ningxia Coal Industry Co., Ltd., CHN Energy, Yinchuan 750011, China
Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes, Huang Zhongzheng, Jiang Guoqing, Wang Jun, Cheng Jiulong, Ma Zhi, Tian Chuxiao, Xin Chengtao
Coal Geology & Exploration
Closed poor boreholes connect aquifers at some degree to form well concealed water diversion channels, which poses a water hazard threat on either tunneling or working bench recovery. In order to discuss the effectiveness of using the transient electromagnetic method in the advance detection of closed poor boreholes for the mine, the 3D geologic-geophysical model of the closed poor boreholes in front of the tunneling working bench was established based on the full-space transient electromagnetic theory to simulate and study the response characteristics of the full-space transient electromagnetic field in the influence area model of closed poor boreholes. As indicated …
Experimental Study On Nondestructive Testing Of Anchor Cable In Pumped Storage Power Station,
2022
Xinjiang Fukang Pumped Storge Power Company Limited, Urumqi 830000 China
Experimental Study On Nondestructive Testing Of Anchor Cable In Pumped Storage Power Station, Yan Liangping, Zhou Liming, Cui Botao, Wang Bolin, Lu Jiangang
Coal Geology & Exploration
In order to demonstrate the effect of elastic wave reflection method, the nondestructive testing test of anchor cables was carried out at the bank slope of Fukang Pumped Storage Power Station in Xinjiang. On the basis of the basic theory of elastic wave reflection method, the anchor cable sensor is embedded, and the data acquisition, signal excitation position and wave velocity of anchor body in the process of nondestructive testing of anchor cable are systematically studied. The following results are obtained: When the receiving sensor position is fixed and the excitation part is the steel strand where the receiving sensor …
Development And Application Of A Retractable Slip Overshot In Underground Coal Mines,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Development And Application Of A Retractable Slip Overshot In Underground Coal Mines, Wu Tao
Coal Geology & Exploration
The stuck and buried drills in underground coal mines often lead to accidents of broken drill pipes in the holes. At present, the success rate of the commonly used fishing methods of male and female fishing tap buckle is low, which not only consumes a lot of manpower and material resources, but also affects the production progress of coal mining. Based on this, a retractable slip overshot with the structural design of the cooperation between the slips and the outer cylinder through the wedge-shaped spiral surface has been proposed, which converts the pull-out force of the drill rod into a …
Study On Long-Distance Fixed-Point Sealed Coring Technology In Broken-Soft Coal Seam,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Study On Long-Distance Fixed-Point Sealed Coring Technology In Broken-Soft Coal Seam, Long Weicheng, Sun Siqing, Chen Jian
Coal Geology & Exploration
With the rapid development of mining, drilling and other technologies in the field of coal mine and the increasing demand for enhancing production and profit in the coal mine, the demand is increasingly urgent for detection of coal seam gas content in the initial stage. In recent years, the gas content measurement technology of underground long borehole high-pressure water sealed coring has been applied in the medium hard coal seam mining area with remarkable effects, but its application is limited in broken-soft coal seam. A number of issues are encountered that easy breakup of coal core sample, easy wall collapse …
Research On Hydraulic Fracturing Technology And Equipment Of Directional Long Drilling With Sand In Coal Seam Roof,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Research On Hydraulic Fracturing Technology And Equipment Of Directional Long Drilling With Sand In Coal Seam Roof, Zhang Jian, Liu Le, Zhao Jizhan, Sun Siqing, Wang Chenyang
Coal Geology & Exploration
Due to low permeability, fast gas-rate decline, uneven fracturing, easy fracture closure, it is difficult to perform advance gas extraction in broken-soft coal seams. Aimed at these issues, this study has been proposed a new idea to enhance the coalbed permeability and eventually the gas extraction, which is based on roof-supporting, long-reach directional drilling, and hydraulic fracturing. Corresponding equipment including fracturing pump unit, directional sandblasting perforation assembly, sand control packer and tools have been developed. Specifically, the pumping unit is capable of a pumping rate up to 90 m3/h, a pumping pressure up to 70 MPa, and a …
Optimized Design And Surface Additive Technology Of Pdc Bit For Hard Rock Directional Drilling,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Optimized Design And Surface Additive Technology Of Pdc Bit For Hard Rock Directional Drilling, Wang Chuanliu, Jin Xin, Gao Xiaoliang, Zhang Peng
Coal Geology & Exploration
Directional long drilling is the main technical means of gas and water hazard control in coal mines, and the performance of PDC directional bit is an important factor which affects the drilling efficiency in hard rock. In view of frequent tripping and low that caused by the broken PDC bit body and PDC tooth collapse in the construction of directional long drilling in the roof and floor of coal seams, the principle of equal cutting teeth distribution is used to optimize the blade teeth distribution to reduce the impact damage of the cutter. Through the simulated analysis of fluid mechanics, …
Research Progress And Development Trend Of Staged Hydraulic Fracturing Technology In Long-Borehole Underground Coal Mine,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Research Progress And Development Trend Of Staged Hydraulic Fracturing Technology In Long-Borehole Underground Coal Mine, Sun Siqing, Li Wenbo, Zhang Jian, Chen Dongdong, Zhao Jizhan, Zheng Kaige, Long Weicheng, Wang Chenyang, Jia Bingyi, Du Tianlin, Liu Le, Yang Huan, Dai Nan
Coal Geology & Exploration
Since the “13th Five-Year Plan”, significant progress has been made in the directional long-borehole staged hydraulic fracturing technology, equipment development and engineering demonstration application of underground coal mine through the technical research, equipment development and engineering test with directional long-borehole and staged hydraulic fracturing technology in combination, focusing on the two major issues of regional permeability enhancement, efficient gas drainage and rock weakening treatment of hard roof for coal seams in underground coal mine in China. It is mainly manifested in the following four aspects: (1) Two staged hydraulic fracturing technologies and tools with/without rig movement have been developed. Specifically, …
Study Of Technologies And Equipment Of Continuous Hydraulic Sand Fracturing For Permeability Enhancement At High Pressure Side Of Coal Mine Downhole,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China; College of Safety Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Study Of Technologies And Equipment Of Continuous Hydraulic Sand Fracturing For Permeability Enhancement At High Pressure Side Of Coal Mine Downhole, Jia Bingyi, Li Shugang, Chen Dongdong, Lin Haifei, Zheng Kaige, Sun Siqing, Zhao Jizhan
Coal Geology & Exploration
The technological concept of sand fracturing at the high pressure side is proposed against the present situation where the coal mine downhole operation space is small, the power and water supply capacities are limited, and the surface sand fracturing equipment cannot be applied directly in the coal mine downhole. On the basis of the principle of sand mixing and carrying through hydrodynamic impact, the continuous hydraulic sand fracturing equipment at the high pressure side was developed. Such equipment requires no external power source for sand mixing. It forms cyclone impact through the changes in the flow regime and flow field …
Dynamic Disaster Evolution Mechanism Of High Mine Pressure At Hard Roof And Advance Area Prevention And Control Technology,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology Engineering Group Corp., Xi’an 710077, China; School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China
Dynamic Disaster Evolution Mechanism Of High Mine Pressure At Hard Roof And Advance Area Prevention And Control Technology, Zheng Kaige, Wang Lintao, Li Bingang, Li Yanjun, Yang Huan, Yang Sen, Dai Nan, Wang Haojie, Wang Zeyang, Xi Jie
Coal Geology & Exploration
The overlying roof on the hard roof working bench is usually not likely to fall off, while tends to form dynamic pressure disaster. The stress evolution characteristics and roof breaking mechanism before and after hard roof weakening were analyzed and revealed using the methods of numerical simulation and theoretical analysis, and the advance area prevention and control technology were proposed and applied in the field practice, for the typical dynamic disaster problem of high mine pressure that was caused by the hard roof against the background of the Buertai Coal Mine in the Shendong Mine Area. As indicated by the …
Enhanced Gas Drainage Technology By Staged Fracturing In Long Bedding Borehole In Hard Coal Bed Of Underground Coal Mine And Its Application,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China; Safety College Xi’an University of Science and Technology, Xi’an 710054, China
Enhanced Gas Drainage Technology By Staged Fracturing In Long Bedding Borehole In Hard Coal Bed Of Underground Coal Mine And Its Application, Wang Chenyang, Li Shugang, Zhang Yongtao, Guo Yi, Sun Siqing, Chen Dongdong, Dou Chengyi
Coal Geology & Exploration
In view of the problems of rapid attenuation, long period and low efficiency of gas drainage in hard coal bed, the enhanced gas drainage technology of increasing the permeability of coal bed by staged fracturing in long bedding borehole was put forward for the medium-to-hard coal bed. Herein, research was conducted on No.4 coal bed of Shaanxi Binchang Mining Area. Specifically, the change characteristics of micro-pore structure of coal body before and after hydraulic fracturing were comparatively analyzed by high-resolution electron microscope (SEM) in the laboratory. Meanwhile, the stress characteristics of packer and the stability of borehole were simulated with …
Floor Failure Law Of Extra-Thick Coal Seam In Fully Mechanized Caving Mining,
2022
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Floor Failure Law Of Extra-Thick Coal Seam In Fully Mechanized Caving Mining, Guo Guoqiang
Coal Geology & Exploration
The coal mining on the high-artesian water body will cause floor disturbance and damage, and lead to the thinner effective waterproof stratum, which enhances the risk coefficient of water bursting at the floor. Grouting modification of the target horizon is an effective governing measure. However, the grouting within the floor damage scope will waste a large amount of grout and affect the project effect. Therefore, it is especially important to carry out the study of the damage depth and regularity of the coal seam floor. Accordingly, the 5105 working bench of the Yushupo Coal Mine in Shanxi was adopted as …
Study Of Constitutive Model Of Frozen Sandstone Damage Based On Weibull Distribution,
2022
China Railway 16th Bureau Group 5th Engineering Co. Ltd, Tangshan 064000, China
Study Of Constitutive Model Of Frozen Sandstone Damage Based On Weibull Distribution, Yi Ming, Zhao Tao, Ma Feifei, Wang Lei, Yuan Chao
Coal Geology & Exploration
Abstract: The deformation and destruction characteristics of frozen rock is a basic mechanical problem encountered during the construction using the freezing method. Under the action of load, the mechanical characteristics and deformation characteristics are greatly different for the rock with different freezing temperatures, which significantly affects the safety and stability of the freezing wall. Therefore, the study of the damage constitutive relation of the frozen rock is significant for instructing the freezing method design and construction. In order to analyze the whole process of the frozen rock deformation and destruction under load action, the Weibull distribution was adopted to describe …
Analysis On Spatio-Temporal Evolution Law Of Freezing Temperature Field In Eastern Shaft Of Qinan Coal Mine,
2022
School of Civil Engineering, Anhui University of Science and Technology, Huainan 232001, China
Analysis On Spatio-Temporal Evolution Law Of Freezing Temperature Field In Eastern Shaft Of Qinan Coal Mine, Huang Shiqing, Rong Chuanxin, Long Wei, Ma Haochen, He Junzhen
Coal Geology & Exploration
Three numerical calculation models of the freezing temperature fields with different soil nature and different burial depths, i.e. the calcareous clay horizon with the burial depth of 218 m, the fine sand horizon with the burial depth of 225 m and the sandy clay horizon with the burial depth of 259 m, were established respectively using the finite element software COMSOL Multiphysics based on the actual forming locations of freezing holes, with the engineering background of using the freezing method in shaft sinking for the eastern air shaft of Qinan Coal Mine Anhui Province and the study object of the …
Experimental Study On Power Matching Of Modular Double Pumping Stations Of Tunnel Drilling Rig,
2022
China Coal Research Institute, Beijing 100013, China; Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Experimental Study On Power Matching Of Modular Double Pumping Stations Of Tunnel Drilling Rig, Lu Feifei, Fan Dong, Tian Hongliang
Coal Geology & Exploration
In order to solve the problems of heavy weight, relocation and transportation of the power pumping station of tunnel drilling rigs, it is proposed to divide the pumping station through modular design, and adopt the solution of small-displacement, dual-power and dual-pump confluence, effectively reducing the transportation size and weight of a single pump station. A single-pump station or a double-pump confluence is chosen according to the working conditions to improve the flexibility of the drilling rig and reduce energy consumption. The load-sensing system has the advantages of energy saving, good load adaptability, and convenient speed regulation. However, when the dual-load-sensing …
Innovative Measure On Achieving Common Prosperity: Carbon Transfer Payment,
2022
FieldsREG AI Ltd., Sanya 572022, China
Innovative Measure On Achieving Common Prosperity: Carbon Transfer Payment, Peili Lu, Lanling Peng, Jiaqi Shen, Yanrui Jin, Yong Geng
Bulletin of Chinese Academy of Sciences (Chinese Version)
To achieve carbon peak and carbon neutrality, as well as common prosperity, is the key decision of the Chinese government. By addressing coordinated regional development and based upon balanced and reasonable distribution of income and carbon emission rights principles, the study aims to develop an equilibrium model to achieve regional carbon transfer payment. Carbon transfer payment can help adjust regional fiscal revenues so that the income distribution system is more in line with the scientific normal distribution characteristics under the common prosperity goal. Such a measure can address both equity and efficiency, balance carbon emission rights and development rights, contribute …
