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- Keyword
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- Numerical simulation (89)
- Coalbed methane (47)
- Coal mine (39)
- Ordos Basin (33)
- Coalbed methane (CBM) (31)
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- Deep learning (28)
- Gas drainage (28)
- Pore structure (28)
- Deep coalbed methane (CBM) (27)
- Permeability (27)
- Deep coalbed methane (25)
- Hydraulic fracturing (23)
- Tar-rich coal (23)
- Directional drilling (21)
- Underground coal mine (20)
- Coal (17)
- Horizontal well (16)
- Qinshui Basin (16)
- Machine learning (14)
- Open-pit coal mine (14)
- Rock burst (14)
- Shale gas (13)
- Underground coal gasification (UCG) (13)
- Fracture (12)
- Mine water (12)
- Prospect (12)
- Fractal dimension (11)
- Helium (11)
- Intelligent mining (11)
- Microstructure (11)
- Publication Year
Articles 991 - 1020 of 1822
Full-Text Articles in Mining Engineering
Adaptive Electro-Hydraulic System Of Zmk5550tzjf50/120 Truck-Mounted Drilling Rig With Wob Adaptive Control Function, Chang Jianghua, Zhao Liang, Lu Feifei, Wang Longpeng, Yang Jiangbo
Adaptive Electro-Hydraulic System Of Zmk5550tzjf50/120 Truck-Mounted Drilling Rig With Wob Adaptive Control Function, Chang Jianghua, Zhao Liang, Lu Feifei, Wang Longpeng, Yang Jiangbo
Coal Geology & Exploration
The truck-mounted drilling rig is an ideal model for rescue drilling construction due to its strong mobility and wide process adaptability. The traditional truck-mounted drilling rig adopting the mode of hydraulic control and hydraulic drive has the problems of non-intuitive displaying of control parameters and many pipelines, which is hard to achieve the closed-loop control. In case of drilling into the complex formations, the response speed of the driller is often difficult to adapt to changes in working conditions, which is not conducive to the drilling safety. In order to meet the requirements of safety and high automation of rescue …
Formation Mechanism Of Coalbed Methane In Dafosi Mine Field, Huanglong Coalfield, Liu Kaide, Yao Kaiwen, Chen Nengyuan, Fan Zhangqun, Li Shujia, Zheng Han, Yue Wenping, Li Xiaolong
Formation Mechanism Of Coalbed Methane In Dafosi Mine Field, Huanglong Coalfield, Liu Kaide, Yao Kaiwen, Chen Nengyuan, Fan Zhangqun, Li Shujia, Zheng Han, Yue Wenping, Li Xiaolong
Coal Geology & Exploration
Dafosi mine field is a typical low-rank coalbed methane (CBM) field in Binchang mining area of Huanglong Jurassic. There are many coalbed methane wells in the field, but few researches are performed on the formation mechanism of coalbed methane. Thus, it is of great guiding significance to clarify the geochemical characteristics and formation mechanism of coalbed methane (CBM) in the mine field, which could provide important basis for the analysis on productivity difference of high- and low-yield CBM Wells. For this reason, the samples of drained gas at the wellhead of six CBM wells, 22 coal samples of No.4 coal …
Application Of Pneumatic Dth Hammer In Drilling Rescue Of Mine Accidents, Zhao Jiangpeng, Hao Shijun
Application Of Pneumatic Dth Hammer In Drilling Rescue Of Mine Accidents, Zhao Jiangpeng, Hao Shijun
Coal Geology & Exploration
As an efficient percussive rock breaking tool, pneumatic down-the-hole (DTH) hammer has played an important role in drilling rescue of mine accidents at home and abroad. Herein, the technical characteristics of pneumatic DTH hammer were described from the points of rock breaking mechanism, structure type, drilling method and specification, and the reverse circulation type and its characteristics of pneumatic DTH hammer were emphatically analyzed. Besides, the application of forward circulation drilling of pneumatic DTH hammer and the combined deviation correction drilling of pneumatic DTH hammer and mud screw in small diameter drilling, as well as the research progress of pneumatic …
Theory And Experiment Of The Dual-Bit Torque Self-Balancing Drilling System For Rescue Drilling, Gao Ke, Zhang Cong, Zhao Yan, Li Xu, Wen Yumin, Lyu Xiaoshu, Xie Xiaobo
Theory And Experiment Of The Dual-Bit Torque Self-Balancing Drilling System For Rescue Drilling, Gao Ke, Zhang Cong, Zhao Yan, Li Xu, Wen Yumin, Lyu Xiaoshu, Xie Xiaobo
Coal Geology & Exploration
The rapid and safe construction of rescue channel is an effective method to save the trapped person underground after mine accidents. The conventional rescue hole drilling technologies mainly include the downhole hammer percussion drilling technology and the composite drilling technology, which have the disadvantages of large rig structure, complex drilling process, great disturbance to the formation and low target hit rate. In particular, it is easy to have secondary accidents in the fractured strata, and the rescue requirements could not be effectively met. In order to ensure the formation adaptability and wall stability of rescue boreholes, the dual-bit torque self-balancing …
Research And Application Of Multi-Source Information Detection Technology For Drilling Rescue Of Mine, Zheng Xuezhao, Sun Ziyu, Guo Jun, Zhang Duo, Chen Gang, He Qinjian
Research And Application Of Multi-Source Information Detection Technology For Drilling Rescue Of Mine, Zheng Xuezhao, Sun Ziyu, Guo Jun, Zhang Duo, Chen Gang, He Qinjian
Coal Geology & Exploration
Drilling rescue of mine is a new type of rescue technology. In order to quickly and accurately obtain the information on drilling channel, the location distance of the trapped person and the characteristics of the gas environment in the disaster area during rescue, as well as to realize the two-way video and audio communication between the trapped person underground and the rescue commander on the ground, theoretical research and technical development were conducted with the technical methods such as multi-source information fusion, dual-stream network video service, edge computing, intrinsically-safe circuit control, and ultra-wideband radar. Meanwhile, two key technologies were proposed: …
Distribution Characteristics Of Trace Elements In Different Density Fractions Of High-Germanium Coal From Wulantuga, Inner Mongolia, China, Duan Piaopiao, Wang Wenfeng, Ma Mengya
Distribution Characteristics Of Trace Elements In Different Density Fractions Of High-Germanium Coal From Wulantuga, Inner Mongolia, China, Duan Piaopiao, Wang Wenfeng, Ma Mengya
Coal Geology & Exploration
The exploitation and utilization of critical metals in coal measures is of great significance to alleviate the shortage of strategic mineral resources in China. In addition to the critical metal germanium (Ge), the low-rank coal from Wulantuga Coal Mine of Shengli Coalfield in Inner Mongolia, China is enriched with the toxic elements Be, F, As, Hg, Sb and W. Considering the extraction and utilization of key metals and environmental protection, the coal in the study area must be washed. As shown in the previous study, flotation is relatively good for the removal of As, Sb and W inWulantuga coal, but …
Research On Key Technology Of Pipe Jacking Drilling Equipment For Large-Diameter Rescue Borehole Of Coal Mine, Wang Lei, Zhu Yuqin, Zhang Weina, Liu Hao, Zhao Wenbo, Yang Chuang, Wang Guanxiong
Research On Key Technology Of Pipe Jacking Drilling Equipment For Large-Diameter Rescue Borehole Of Coal Mine, Wang Lei, Zhu Yuqin, Zhang Weina, Liu Hao, Zhao Wenbo, Yang Chuang, Wang Guanxiong
Coal Geology & Exploration
In order to solve the rescue problem of collapsed roadways in coal mines and improve the drilling speed of large-diameter rescue boreholes, the construction method of large-diameter borehole with pipe jacking technology was proposed. Specifically, the collapsed rock mass was crushed and the slag was removed by pushing the connectable pipe joints and cutter heads with the main jacking equipment arranged in the chamber, so as to form a rescue channel composed of jacked pipes at last. A composite cutter head with large opening under the condition of collapsed rock mass was developed, which is composed of 10 cutters, 10 …
Quantitative Experimental Study On Time-Varying Characteristics Of Bleeding Of Cement-Based Grouting Materials, Zhang Runqi, Xu Bin, Yin Shangxian, Li Shuxia, Chang Yongwang, Lian Huiqing, Cao Min
Quantitative Experimental Study On Time-Varying Characteristics Of Bleeding Of Cement-Based Grouting Materials, Zhang Runqi, Xu Bin, Yin Shangxian, Li Shuxia, Chang Yongwang, Lian Huiqing, Cao Min
Coal Geology & Exploration
Cement-based cementitious materials are the most common grouting materials for grouting engineering. This type of material has obvious water separation effect, and obtaining the quantitative formula of water separation thickness will be helpful to improve the calculation accuracy of slurry diffusion radius. By observing the water separation process of three admixtures, namely pyrophyllite powder (0%-35%), polyvinyl alcohol (0%-8%) and fly ash (0%-90%) in cement-based slurry, the water separating rate, stone formation rate, final water separation time and water separation thickness of the three admixtures were obtained. It is found that the water separation thickness of the slurry varies regularly with …
Digital Twin Technology Of Geological Information In Mining And Excavation Working Face, Li Peng, Cheng Jianyuan
Digital Twin Technology Of Geological Information In Mining And Excavation Working Face, Li Peng, Cheng Jianyuan
Coal Geology & Exploration
The mine geology transparency is the basis for the intelligent coal mine construction. 3D geological modeling is an important measure for realizing the mine geology transparency. In the geological modeling of the previous working face, there are problems including the discrepancy between the interpolation algorithm and the geological law, the low fusion level of the multi-source heterogeneous geological data, and the seldom coupling between the coal mine production equipment and the geological information. The concept of the digital twin of the geological information about coal mine working face was proposed, the discrete smooth interpolation (DSI) algorithm was adopted, and the …
Subgrade Subsurface Anomalous Body Full-Waveform Inversion Based On Ground-Penetrating Radar, Hu Leilei, Chen Kang, Huang Dejun, Yang Rong
Subgrade Subsurface Anomalous Body Full-Waveform Inversion Based On Ground-Penetrating Radar, Hu Leilei, Chen Kang, Huang Dejun, Yang Rong
Coal Geology & Exploration
The hidden dangers of road collapse and underground voids are usually difficult to notice and easy to occur in sudden. They have caused huge losses in people's lives and properties. Therefore, the detection and analysis of road collapse and underground voids are crucial. The ground-penetrating radar (GPR) is the main method for detecting the hidden dangers of urban road collapse currently by virtue of its high accuracy, high efficiency, continuous non-destructiveness and real-time imaging. A convolution type objective function FWI algorithm was proposed to solve the problem of the lower inversion accuracy and practicability caused by the inaccurate estimation of …
Table Of Contents, The Editors
Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan
Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan
Coal Geology & Exploration
Irregular coal seam mining is easy to cause the problems such as roof stress concentration and abnormal ground pressure behavior. In order to explore the roof fracture law and the structural evolution characteristics of stope with variable length, the roof structure models with four types of boundary conditions were established and analyzed using the small-deflection thin plate bending theory in view of the geometric characteristics and mechanical causes of the abrupt stope with the inclined length of working face changing from small to large in various mining stages. Meanwhile, the roof fracture law and macro-mechanical response were analyzed by MATLAB …
Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale
Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale
Coal Geology & Exploration
Permeability is an important parameter to characterize gas flow. In order to ensure the safe and efficient gas drainage, it is necessary to explore the evolution characteristics of coal reservoir gas seepage at different positions from the producing wellbores. However, the effective stress, the gas adsorption/desorption capacity of coal matrix and the temperature of coal reservoir are constantly changing with the gas drainage, and even the drainage damage may occur, which makes the gas migration behavior in coal seam extremely complicated. In order to explore the seepage characteristics of coal reservoir gas during gas drainage, the space-time evolution function of …
Research And Application Progress Of Energy Underground Structures, Wen Jiwei, Hou Junlong, Liu Xinghong, Zeng Xian’En, Xiang Tian
Research And Application Progress Of Energy Underground Structures, Wen Jiwei, Hou Junlong, Liu Xinghong, Zeng Xian’En, Xiang Tian
Coal Geology & Exploration
Energy geostructure refers to a type of structure equipped with heat exchange pipe in the building foundation element and the underground structure, which has the functions of load bearing and heat exchange. It not only effectively saves the valuable and irreversible underground space resources, but also makes full use of the non-carbon based continuous, stable, safe and clean geothermal energy resources, thus having more advantages than the traditional Ground Source Heat Pump (GSHP). Herein, the concept, advantages, research and application progress of energy geostructure at home and abroad were systematically summarized. Moreover, the current situation of four common energy geostructures, …
Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng
Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng
Coal Geology & Exploration
The buried pipeline is the part where the rock mass heat pump system performs direct heat transfer with the ground. The water-bearing structure in the karst area is complex and diverse, which has a significant impact on the heat transfer and storage of the buried pipeline group. Herein, the heat transfer process of a group of 27 vertical buried pipelines in four geological structure types was simulated, including the non-karst structure, fractured karst structure, karst conduit structure and mixed karst structure. Meanwhile, comparison was made for the change of parameters, such as the temperature field in the rock mass, the …
Numerical Simulation On Azimuth Gamma Ray Detection Of Coal And Rock Interface, Chen Gang, Chen Long, Li Quanxin, Liu Zhiyi
Numerical Simulation On Azimuth Gamma Ray Detection Of Coal And Rock Interface, Chen Gang, Chen Long, Li Quanxin, Liu Zhiyi
Coal Geology & Exploration
In order to meet the requirements of geosteering drilling with LWD azimuth gamma, the response value of gamma ray intensity under different surrounding rock thicknesses and absorption coefficients was studied by numerical simulation. Meanwhile, the variation of special and physical characteristics reflected by API value measured by gamma detector under the radioactive formation conditions was simulated and analyzed. On this basis, the geological model of the three layers of coal, mudstone and limestone of 8-sectors azimuth gamma ray drilling was established to simulate the identification process of roof and floor of coal bed drilled. The simulation results show that the …
Status And Prospect Of Harmless Disposal And Resource Comprehensive Utilization Of Solid Waste Of Coal Gangue, Wang Yutao
Coal Geology & Exploration
A large amount of coal gangue generated during coal production and processing is piled up on the surface, which not only causes land occupation and soil erosion, but also causes geological disasters such as landslides and debris flows. So it has a serious impact on the ecological environment of the mining area. The cumulative stockpile of coal gangue in China has exceeded 6 billion tons, accounting for 13000 hectares of land. In 2020, the output of coal gangue in China is 729 million tons, the comprehensive utilization is 526 million tons, and the comprehensive utilization rate is 72.2%. At present, …
Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo
Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo
Coal Geology & Exploration
To solve the problems of poor application flexibility and non-adjustable performance of the current fracturing fluid system in unconventional natural gas of coal measures, an integrated fracturing fluid system is researched. In this study, the experimental evaluation was performed for the viscosity increase, drag reduction, sand suspension, temperature and shear resistance, gel breaking, additive compatibility, anti-swelling and surface tension of the integrated fracturing fluid system based on three kinds of integrated thickeners in combination with the field clay stabilizer, cleanup additive and gel breaker. Meanwhile, the field application effect of integrated fracturing fluid was analyzed. The results show that: the …
Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun
Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun
Coal Geology & Exploration
At present, there is no fixed way to predict the sensitive zones of subsidence disaster development in underground coal mining areas, and the prediction result of sensitive zones has a great uncertainty. Herein, the subsidence disaster in Xishan area of Taiyuan City, Shanxi Province was taken as the research object. Totally 4 types of kernel SVM based prediction model for sensitivity zoning of subsidence disaster were constructed with the methods of GIS spatial analysis, statistical analysis and Support Vector Machine (SVM) in combination, taking the subsidence disaster data checked and recorded in 2012 and 2014 as the modeling and verification …
Table Of Contents, The Editors
Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying
Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying
Coal Geology & Exploration
The coal measure fault zone generated by the superimposition of the polytropic movement and multiple structure has important effects on the coal seam gas occurrence. The method of combining the geologic analysis, COMSOL Multiphysics numerical simulation and field data monitoring was adopted to analyze the interaction relations between the stress distribution characteristics and faults of the normal fault zone in the coal measure, study the coal seam permeability variation characteristics influenced by the normal fault zone in the coal measure, and simulate the gas migration status and concentration distribution condition after the formation of the normal fault zone. The coal …
Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei
Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei
Coal Geology & Exploration
Lithium (Li) is an important energy metal, and the global demand for Li has grown rapidly in recent years. The discovery of coal-associated Li deposits in China proves that coal mines may serve as a potential alternative of Li resources. No.20 coal seam in Pu’an mining area in Guizhou province of China was selected as the study object. The basic properties, mineral composition, elemental composition, and occurrence modes of Li of the raw coal and six density-graded samples (obtained through a float-sink test) were determined by using coal proximate analysis, optical microscope, X-Ray fluorescence spectroscopy (XRF), inductively coupled plasma mass …
Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang
Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang
Coal Geology & Exploration
Crossing ditch mining of shallow coal seam is common in northern Shaanxi mining area, which seriously threatens the safe production and the sound ecological development. The mining-induced overburden fractures and surface cracks are developed as a result of the extension and expansion of microcracks in rock mass. In order to more systematically study the evolution law of overburden microcracks in crossing ditch mining of shallow coal seam, a numerical model of particle flow in coal mining was established with the Particle Flow Code (PFC) numerical simulation platform according to the field ditch profile and borehole data under the background of …
Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie
Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie
Coal Geology & Exploration
Stress relaxation often occurs in the saturated soft clay with poor water permeability under the actual working condition at fast construction speed (fast loading rate), which brings huge hidden dangers to the safe operation of engineering practice. Herein, the unconsolidated undrained triaxial shear test was performed based on the soft dredger fill in Tianjin Binhai using the WF stress path triaxial instrument, and the influence law of such factors as the different initial strain, confining pressure, shear rate, sampling depth and structural properties of the soft dredger fill on its stress relaxation characteristics was analyzed accordingly. According to the test …
Spatial Variation Characteristics Of Soil Heavy Metal Speciation And Bioavailability In Coal Gangue Accumulation Area—Taking Fengfeng Mining Area As An Example, Sun Tao, Song Shijie, Chang Qing, Wang Chenchen, Zhang Yanjie, Peng Ruisi, Wang Yi
Spatial Variation Characteristics Of Soil Heavy Metal Speciation And Bioavailability In Coal Gangue Accumulation Area—Taking Fengfeng Mining Area As An Example, Sun Tao, Song Shijie, Chang Qing, Wang Chenchen, Zhang Yanjie, Peng Ruisi, Wang Yi
Coal Geology & Exploration
The surface accumulation of coal gangue is a typical form of ecological environment destruction in the eastern coal mining area of China, and the prevention and control of heavy metal pollution in the soil in the accumulation area has become a hot spot in the current research. Taking the shallow soil (with a vertical depth of 40 cm and below) around a coal gangue mountain (within a radius of 300 m) in use in the Fengfeng mining area of Hebei as the research object, the active state, iron manganese oxidation state, organic state and residue state of four kinds of …
Effect Of Initial Adhesion On Shear Strength And Deformation Characteristics Of Interfaces In Heterogeneous Soils, Zhu Yanbo, Yang Fanfan, Miao Shuaisheng, Li Futong, Zhang Yuxuan
Effect Of Initial Adhesion On Shear Strength And Deformation Characteristics Of Interfaces In Heterogeneous Soils, Zhu Yanbo, Yang Fanfan, Miao Shuaisheng, Li Futong, Zhang Yuxuan
Coal Geology & Exploration
In the Loess Plateau of China, the interface between the Loess and Hipparion Red Clay is widely distributed. The initial adhesion between this interfaces plays an important role in its shear strength. To investigate the effect of initial adhesion on shear strength and deformation characteristics of the interfaces, we firstly performed a series of direct shear experiments. Then, we discussed the effects of initial adhesion on failure mode, shear deformation and shear strength of interfaces. The results indicate that the failure modes of interfaces with initial adhesion and interfaces without initial adhesion are different. The initial adhesion improves the sliding …
Time-To-Depth Conversion Accuracy Analysis And Improvement Method For Inclined Coal Bed, Wang Huifeng, Fu Chao, Li Guo, Chen Tongjun
Time-To-Depth Conversion Accuracy Analysis And Improvement Method For Inclined Coal Bed, Wang Huifeng, Fu Chao, Li Guo, Chen Tongjun
Coal Geology & Exploration
The average-velocity method is the most commonly-used time-to-depth conversion technology for the seismic survey of coalbed. But for the steeply-inclined coalbed, the average velocity changes rapidly laterally, and the interpretation accuracy varies greatly, so that the intelligent coal mining could not be assured effectively. Herein, the accuracy of various average-velocity-interpolation methods was discussed by analyzing a steeply-inclined coalbed model and a practical 3D seismic mining area and appropriate improvement methods were proposed accordingly. The calculation results of a forward model show that the bottom elevation accuracy of coalbed is greatly affected by the locations of interpolation points in the case …
Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei
Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei
Coal Geology & Exploration
In borehole enlarge drilling, it is necessary to adjust the flow of mud pump to switch drilling and borehole enlarging state, and the control effect is not ideal. To improve the precision of the borehole enlarging technology while drilling machinery control, a pump-free double channel mechanical borehole enlarging drill bit was developed, which equiped with dual channel to form a complete set of double channel drill pipe and double channel water device. Two sets of individual waterways were designed, annulus water way for cooling bit and carry out rock powder, and center water way is used to control the opening …
Air-Driven Directional Drilling Technology And Equipment In Soft Coal Seam Of Huainan Mining Area, Tian Hongliang, Chen Jian, Zhang Jie, Cheng Heyu, Dong Ruigang, Du Limeng, Liu Degui, Guan Qiangsheng
Air-Driven Directional Drilling Technology And Equipment In Soft Coal Seam Of Huainan Mining Area, Tian Hongliang, Chen Jian, Zhang Jie, Cheng Heyu, Dong Ruigang, Du Limeng, Liu Degui, Guan Qiangsheng
Coal Geology & Exploration
Aiming at Huainan mining area using bedding directional drilling to eliminate gas outburst in strip coal seams of working face and adjacent roadways, we put forward a technical idea of using pneumatic long directional drilling hole to eliminate gas outburst by one hole. On the basis of the previous pneumatic screw directional drilling technology test, we developed a narrow-body full-section remote directional drilling rig with a width of only 1.1 m, the spindle angle can be stepless adjusted from −90° to 90°, and maximum remote distance of 50 m. The ø73/82 mm screw pneumatic screw drill was optimized, with maximum …
Influencing Factors Of Increasing The Signal Strength Of The Em-Mwd By Applying Insulation Coating Outside The Casing, Shao Chun, Hu Chuang, Xu Lin, Chen Minghua, Long Xiaoping
Influencing Factors Of Increasing The Signal Strength Of The Em-Mwd By Applying Insulation Coating Outside The Casing, Shao Chun, Hu Chuang, Xu Lin, Chen Minghua, Long Xiaoping
Coal Geology & Exploration
Applying insulation coating outside the casing can reduce the attenuation of Electromagnetic measurement-while-drilling (EM-MWD) signals in low resistivity formations and increase the transmission depth of EM-MWD signals. For the purpose of obtaining the resistivity range of the formation applicable to the insulation coating and the influence of the coating characteristics on the received signal strength, a simulation model is established based on the finite element method, and simulation experiments are carried out on the application effect of the insulation coating applied to the casings of different resistivity formations and the influence regularity of the coating resistivity, thickness and length on …