Open Access. Powered by Scholars. Published by Universities.®

Sustainability Commons™

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1351 - 1380 of 2611

Full-Text Articles in Sustainability

Research And Application Of The Prediction Method For Cbm Enrichment Area Of Low Rank Coal, Luo Zhongqin, Liu Peng, Meng Fanbin Research Institute Of Coal Geophysical Exploration, China National Administration Of Coal Geology, Zhuozhou 072750, China Dec 2021

Research And Application Of The Prediction Method For Cbm Enrichment Area Of Low Rank Coal, Luo Zhongqin, Liu Peng, Meng Fanbin Research Institute Of Coal Geophysical Exploration, China National Administration Of Coal Geology, Zhuozhou 072750, China

Coal Geology & Exploration

The exploration of low rank coal coalbed methane(CBM) faces the problems of low resource exploration rate and low single well production. And medium and low rank coal CBM exploration is still in the primary stage. In order to improve the predition accuracy of the low rank coal CBM enrichment area, the laboratory test data of 652 coal samples from 56 wells in Hancheng, Jincheng Baode, Ji'ergalangtu Qinshui Basin, Huainan, Huaibei and other places were collected to compare the relationship between gas content and elastic parameters of high, medium and low rank coal samples. The results indicated that the correlation between …

Go to article

Mechanism And Effect Analysis Of Enhanced Gas Drainage With Large Diameter Double Boreholes, Zhang Chunhua, Zhang Zijian, Nian Jun, Jiao Dengming Dec 2021

Mechanism And Effect Analysis Of Enhanced Gas Drainage With Large Diameter Double Boreholes, Zhang Chunhua, Zhang Zijian, Nian Jun, Jiao Dengming

Coal Geology & Exploration

To study the mechanism of enhanced gas drainage with large diameter double boreholes, numerical models of single holes with different diameters and double ø350 mm holes were established by using the RFPA2D-Gas software in working face 30110 of Shiquan Coal Mine, Shanxi Province. Stress distribution, damage and fracture, gas permeability evolution and gas migration law of the coal around the hole were analyzed, and then the extraction effect of double ø350 mm holes was investigated. Simulation results show that the pressure relief radii of the ø100 mm, ø250 mm, ø350 mm and double ø350 mm holes are 0.25 …

Go to article

Factors Affecting The Attitude Accuracy Of Wireless Electromagnetic Wave Mwd System, Wang Xiaobo Dec 2021

Factors Affecting The Attitude Accuracy Of Wireless Electromagnetic Wave Mwd System, Wang Xiaobo

Coal Geology & Exploration

In broken soft coal seams of coal mine where hydraulic driving directional drilling is used, hole collapse and hole wall instability are easy to occur. Electromagnetic wave measurement while drilling system is suitable for gas driving drilling, so it is widely used in broken soft coal seams. The accuracy of drilling trajectory is the key to gas drainage effect in broken soft coal seams. In the use of electromagnetic wave measurement while drilling system, the phenomenon of insufficient accuracy and large error of trajectory measurement appears irregularly. In order to solve this problem, this paper analyzes all the factors that …

Go to article

Characteristics Of The Shale Gas Reservoirs And Evaluation Of Sweet Spots In Wufeng Formation And Longmaxi Formation In Jingmen Exploration Area, Li Xiaoming, Liu Jirong, Lin Wen, Ma Lihong, Liu Dexun, Chen Yujie Dec 2021

Characteristics Of The Shale Gas Reservoirs And Evaluation Of Sweet Spots In Wufeng Formation And Longmaxi Formation In Jingmen Exploration Area, Li Xiaoming, Liu Jirong, Lin Wen, Ma Lihong, Liu Dexun, Chen Yujie

Coal Geology & Exploration

In order to further clarify the resource potential of shale gas from Wufeng Formation to Longmaxi Formation in Jingmen exploration area, sweet spots were selected. The shale in Wufeng Formation and 1th Member of Longmaxi Formation of the well X was taken as the research object in this study. Using sliced kerogen, X-ray diffraction, nuclear magnetic resonance, micro nano CT scanning, geochemical analysis and other testing methods, combined with logging interpretation results, based on the petrology, organic geochemical and mineral composition, physical properties, pore types and structure characteristics and hydrocarbon content, the reservoir characteristics of Wufeng-1th Member of the …

Go to article

Analysis Of Organic Matter Maturity Of Sapropel Coal In Oil Layer A Of Haishiwan Mine Field Of Yaojie Mining Area, Song Xiaozhong, Zhang Bingzhong, Lei Ying, Song Yanqiang Dec 2021

Analysis Of Organic Matter Maturity Of Sapropel Coal In Oil Layer A Of Haishiwan Mine Field Of Yaojie Mining Area, Song Xiaozhong, Zhang Bingzhong, Lei Ying, Song Yanqiang

Coal Geology & Exploration

The vitrinite reflectance is recognized as the only comparable evaluation index of organic matter maturity of source rock in the exploration and development of oil and gas, shale gas and coalbed methane resources. Current research was done to determine the organic matter maturity of sapropel coal in oil layer A in Haishiwan mine field more accurately. Coal samples were collected from boreholes and observation of the optical characteristics of reflected light and fluorescence microscopic components were studied under the microscope. It was found that there are two different characteristic vitrinites in sapropel coal in oil layer A. One was fluorescent …

Go to article

Deformation Characteristics Of Coal Measures And Gas Occurrence Law Of Coal Mines In North China, Wang Wei, Wei Yanzhao, Jia Tianrang, Yan Jiangwei Dec 2021

Deformation Characteristics Of Coal Measures And Gas Occurrence Law Of Coal Mines In North China, Wang Wei, Wei Yanzhao, Jia Tianrang, Yan Jiangwei

Coal Geology & Exploration

Gas is not only one of the important disaster-causing factors in coal mines, but also an important clean energy. Understanding the deformation characteristics of coal measures and the occurrence of gas is the basis for coal mine gas disaster prevention and coalbed methane development. Taking the North China coal measures as the research object, taking the tectonic evolution and control as the main line, using the theory of plate tectonics, tectonic evolution and step by step control of gas-occurring structures, the deformation characteristics of the North China coal-measures and the law of coal mine gas occurrence were systematically studied. The …

Go to article

Discussion On The Water-Preserved Coal Mining By Dewatering-Reflooding Water Curtain In Open-Pit Coal Mines, Li Ying, Yang Zhuo, Wu Tong Dec 2021

Discussion On The Water-Preserved Coal Mining By Dewatering-Reflooding Water Curtain In Open-Pit Coal Mines, Li Ying, Yang Zhuo, Wu Tong

Coal Geology & Exploration

To suppress the attenuation of groundwater resources caused by drainage and control the influence range of coal mining on groundwater resources, the coal mining technology with water curtain was adopted. Taking an open-pit coal mine as the background, this paper established a sand trough recharge platform to carry out physical experiments, and used a numerical method to simulate the irrigation area, so as to analyze the formation and variation of the dewatering-reflooding water curtain. Physical experiments were carried out to observe the formation of a fixed head boundary by water injection curtain which prevented the expansion of funnel, the influence …

Go to article

Case Study On The Effects Of Seismic Exploration Beneath The Goafs Of Different Ages, Zhang Zhao, Yin Quanzeng Dec 2021

Case Study On The Effects Of Seismic Exploration Beneath The Goafs Of Different Ages, Zhang Zhao, Yin Quanzeng

Coal Geology & Exploration

With the continuous development of coal resources, the upper group of coal in some coal mines has been mined out, and it is urgent to solve the detection problem of the lower group of coal. Affected by the goaf formed by the upper group of coal, the seismic energy absorption and scattering attenuation of the lower group of coal are significant, and the signal-to-noise ratio of the data is low. The detection of the lower group of coal under the goaf by 3D seismic exploration is still in the exploration stage. In this paper, the 3D seismic exploration project of …

Go to article

Prediction Of Fracture Distribution And Evaluation Of Shale Gas Preservation Conditions In Longmaxi Formation In Dongxi Area, Xie Jiatong, Fu Xiaoping, Qin Qirong, Li Hu Dec 2021

Prediction Of Fracture Distribution And Evaluation Of Shale Gas Preservation Conditions In Longmaxi Formation In Dongxi Area, Xie Jiatong, Fu Xiaoping, Qin Qirong, Li Hu

Coal Geology & Exploration

Commercial development of shale gas confirmed that mature shale has great potential for exploration, southeast Sichuan is the strategic pilot area of shale gas exploration and development in southern China, cracks are the key factor of shale gas preservation and development deployment, for the structural environment complex and special basin edge area, increasing the difficulty of shale crack research, but also provides a new direction for shale gas exploration and development. As a new field of oil and gas exploration in China, shale gas exploration has not yet developed a mature crack evaluation system. Taking Dongxi area of the southeast …

Go to article

Study On The Microscopic Mechanism Of The Loess Improved By Quicklime, Xie Xiao, Wang Luyao, Deng Lejuan, Zhang Guowei Dec 2021

Study On The Microscopic Mechanism Of The Loess Improved By Quicklime, Xie Xiao, Wang Luyao, Deng Lejuan, Zhang Guowei

Coal Geology & Exploration

To investigate the influence of lime content on loess strength and its microscopic mechanism, different proportions of lime were used to improve loess. Through direct shear test, mercury intrusion porosimetry and scanning electron microscopy, the strength characteristics and microstructure changes of compacted loess and modified loess with different lime contents were analyzed qualitatively and quantitatively, and the microscopic mechanism of lime-improved loess was analyzed in depth. The results show that the shear strength parameters of lime-improved loess increases first and then decreases with the increase of lime contents. The cohesive force and internal friction angle reach the maximum when the …

Go to article

A 3d Seismic Physical Modeling System Of Large Double Triaxial Air-Supported Positioning And Multichannel Data Acquisition And Its Application, Shi Xianxin, Liu Qiang, Hu Jiwu, Wang Pan, Lian Chenguang, Jia Qian, Zhang Miaomiao, Nie Ailan Dec 2021

A 3d Seismic Physical Modeling System Of Large Double Triaxial Air-Supported Positioning And Multichannel Data Acquisition And Its Application, Shi Xianxin, Liu Qiang, Hu Jiwu, Wang Pan, Lian Chenguang, Jia Qian, Zhang Miaomiao, Nie Ailan

Coal Geology & Exploration

As an important technology to study seismic wave propagation characteristics, 3D seismic physical simulation is an effective method to understand the propagation law and response characteristics of seismic waves in complex structures. It has the advantages of more realistic results and no limitation on calculation methods and boundary conditions over numerical simulation. Therefore, it has important applications in the research of the basic law of seismic wave propagation, verification of field seismic exploration methods, design optimization of observation systems, etc. This paper presents a 3D seismic physical modeling system of large double triaxial air-supported positioning and multichannel data acquisition, which …

Go to article

Experimental Study On Transient Electromagnetic Method With A Conical Source, Yang Haiyan, Liu Zhixin, Zhang Hua, Chen Xiao, Lian Zhe, Wang Ling, Yang Fujie Dec 2021

Experimental Study On Transient Electromagnetic Method With A Conical Source, Yang Haiyan, Liu Zhixin, Zhang Hua, Chen Xiao, Lian Zhe, Wang Ling, Yang Fujie

Coal Geology & Exploration

A new transmitter device-conical source has been proved theoretically to have several advantages for transient electromagnetic sounding. To verify application ability of conical source, two kinds of transmitter devices were designed and made, and the experimental studies on surface and in mine roadway were carried out. By applying high density resistivity achievements in surface experiment, the detecting results using conical source and multi-coils were compared. The results show that the description of strata resistivity with conical source is better than that with multi-coils. One fault was identified and the strike and position of which matches the high density resistivity result …

Go to article

New Method And Optimization Research On Water Sealing Outside Casing Based On Water-Swelling Rubber For Stratified Pumping, Zheng Xianghua, Yuan Wei, Luo Yunxiang, Cheng Cong Dec 2021

New Method And Optimization Research On Water Sealing Outside Casing Based On Water-Swelling Rubber For Stratified Pumping, Zheng Xianghua, Yuan Wei, Luo Yunxiang, Cheng Cong

Coal Geology & Exploration

Stratified pumping test is a key technique for hydrogeological exploration. To solve the problems of low efficiency and poor reliability and controllability of the traditional water-sealing methods outside casing for stratified pumping, a water-swelling rubber was developed based on high water absorption of the sodium polyacrylate resin, and a new approach based on water-swelling rubber was proposed and optimized by the response surface methodology in this paper. With the water swelling ratio of the rubber as response index, a surrogate model was constructed by the Box-Behnken experimental design to study the influence of different process parameters, working condition parameters, and …

Go to article

Numerical Analysis Of The Effect Of Different Soil Types And Water Content On Heat Transfer Performance Of Horizontal Buried Pipes, Zou Hang, Pei Peng, Hao Dingyi, Wang Chen Dec 2021

Numerical Analysis Of The Effect Of Different Soil Types And Water Content On Heat Transfer Performance Of Horizontal Buried Pipes, Zou Hang, Pei Peng, Hao Dingyi, Wang Chen

Coal Geology & Exploration

In order to reveal the heat transfer performance of the horizontal buried pipe heat exchanger in the ground source heat pump system in different soil types, this paper, based on the theoretical knowledge of soil capillary water, combined with the means of numerical simulation, discusses the influence of the difference of three-phase composition in different types of energy storage soil on the heat transfer characteristics of the horizontal buried pipe heat exchanger. The results show that under the cooling condition of 308.15 K, the outlet water temperature of the horizontal pipe in the loam soil decreases to 303.3 K and …

Go to article

Development And Prospect Of Intelligent Drilling Technology And Equipment For Underground Coal Mines In China, Li Quanxin, Liu Fei, Fang Jun Xi'an Research Institute Co., Ltd., China Coal Technology And Engineering Group Corp., Xi'an 710077, China, Liu Jianlin, Chu Zhiwei Dec 2021

Development And Prospect Of Intelligent Drilling Technology And Equipment For Underground Coal Mines In China, Li Quanxin, Liu Fei, Fang Jun Xi'an Research Institute Co., Ltd., China Coal Technology And Engineering Group Corp., Xi'an 710077, China, Liu Jianlin, Chu Zhiwei

Coal Geology & Exploration

The intelligent drilling technology and equipment are important part of the intelligent construction of coal mine, and it is the advanced technology and equipment urgently needed by coal mine enterprises to further promote the work of reducing personnel and increasing efficiency. The phased achievements of underground intelligent drilling technology and equipment during the 13th five-year plan are systematically summarized, and the development status of key technical equipment such as automatic drilling rig, parameter monitoring of measurement while drilling(MWD) system, rotary steerable system are introduced. The key factors restricting the research and development (R & D) and application of intelligent drilling …

Go to article

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan Dec 2021

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan

Nebraska Water Center: Faculty Publications

The present research reports the level of nitrate (NO3-), associated health risks and possible sources of contamination in groundwater from south India. Many samples (32%) are above or approaching the recommended level of NO3- for safe drinking water. The correlation analysis indicates different sources of NO3- contamination in different regions rather than a common origin. The isotopic measurements provide information about potential nitrogen sources contributing NO3- to the groundwater. Based on isotope analysis, the sources of NO3- in the groundwater of this region are likely to be from (a) …

Go to article

Cover Crop Effects On Near-Surface Soil Aggregate Stability In The Southern Mississippi Valley Loess (Mlra 134), Chandler M. Arel Dec 2021

Cover Crop Effects On Near-Surface Soil Aggregate Stability In The Southern Mississippi Valley Loess (Mlra 134), Chandler M. Arel

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Intensive agricultural cultivation within major land resource area (MLRA) 134, the Southern Mississippi Valley Loess, has led to soil erosion, soil compaction, and the overall destabilization of near-surface soil aggregates. The use of cover crops during the agricultural offseason has been shown to help alleviate soil compaction and provide stabilizing effects against soil erosion, which are particularly important as the silty soils of MLRA 134 have a large erosion potential. This study evaluated the effects of cover crop and no-cover crop treatment on silt-loam soils within MLRA 134. Treatments were implemented during Fall 2018 and Fall 2019 and consisted of …

Go to article

Reinforcement Learning Policy Gradient Methods For Reservoir Operation Management And Control, Sadegh Sadeghi Tabas Dec 2021

Reinforcement Learning Policy Gradient Methods For Reservoir Operation Management And Control, Sadegh Sadeghi Tabas

All Theses

Changes in demand, various hydrological inputs, and environmental stressors are among issues that water managers and policymakers face on a regular basis. These concerns have sparked interest in applying different techniques to determine reservoir operation policy and improve reservoir release decisions. As the resolution of the analysis rises, it becomes more difficult to effectively represent a real-world system using traditional approaches for determining the best reservoir operation policy. One of the challenges is the “curse of dimensionality,” which occurs when the discretization of the state and action spaces becomes finer or when more state or action variables are taken into …

Go to article

A 60- Year Record Of The Demotechnic Index Of States, 1960-2019, Gavin James Kellough Dec 2021

A 60- Year Record Of The Demotechnic Index Of States, 1960-2019, Gavin James Kellough

Graduate Theses and Dissertations

A country’s dependency on energy resources can be interpreted through the calculation of energy indices. The Demotechnic Index (DI) was used to determine the trajectory of energy efficiency of each state in the United States over the period 1960-2019. The DI serves as a measure of the energy intensity of states and a proxy for energy sustainability of each state.The DI is the ratio of total energy use to total metabolic energy demand of a population. Mathematically, DI = (E_T-E_M)/E_M E_T represents the total energy used (metabolic energy + technological energy in kilojoules annually, kJ/y), while EM represents the basic …

Go to article

Evaluation Of Nitrous Oxide Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil In Arkansas, Jordan M. Slayden Dec 2021

Evaluation Of Nitrous Oxide Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil In Arkansas, Jordan M. Slayden

Graduate Theses and Dissertations

As the number one rice (Oryza sativa)-producing state in the United States, Arkansas also ranks fourth as the largest user of groundwater. Recently, due to the development of drought- resistant hybrid cultivars, the furrow-irrigated rice production system has become an increasingly popular alternative to traditional flood-irrigated production with respect to conserving groundwater and maintaining yield. However, other environmental parameters, like greenhouse gas emissions, specifically nitrous oxide (N2O), have yet to be evaluated under furrow-irrigated rice. The objectives of this study were to i) evaluate the effects of site position (i.e., up-, mid-, and down-slope) and tillage treatment [i.e., conventional tillage …

Go to article

Longleaf Pine Restoration In The South Carolina Sandhills Wiregrass Gap, Jacob W. Murray Dec 2021

Longleaf Pine Restoration In The South Carolina Sandhills Wiregrass Gap, Jacob W. Murray

All Theses

Longleaf pine restoration has been a topic of great concern and intrigue in the southeast and has taken on new fervor in recent decades as restoration methods continue to develop. Many landowners and forest managers are now pursuing ecological forestry and restoration ecology in great numbers as a new form of land management. However, niche regions can often be overlooked, as is the case with the Carolina Sandhills Wiregrass Gap, an area devoid of wiregrass and one that is on the outskirt regions of the historical longleaf pine range. Field studies were conducted pre- and post-harvest during two growing seasons …

Go to article

Medium Conditons And Influence Mechanism Of High Salinity Mine Water Transfer And Storage By Deep Well Recharge, Li Xin, Sun Yajun, Chen Ge, Wang Houzhu, Zhang Zhijun Oct 2021

Medium Conditons And Influence Mechanism Of High Salinity Mine Water Transfer And Storage By Deep Well Recharge, Li Xin, Sun Yajun, Chen Ge, Wang Houzhu, Zhang Zhijun

Coal Geology & Exploration

In the arid and semi-arid regions of the Western China, there is not only a shortage of water resources, but also the problems of large mine water inflow and high salinity of mine water. In order to reduce the waste of water resources in the mining activities and protect water ecological environment in the region, it is proposed to treat the mine water by deeper well recharge to the aquifers under the coal seam based on the theories and technical methods such as mine water transfer and storage, water-preserving mining and coal-water dual resource coordinated mining. A test well project …

Go to article

Medium Characteristics And Hydrodynamic Evolution Law Of High Salinity Mine Water Recharge In Deep Well, Liu Qi, Wang Weijun, Luo Bin, Wang Houzhu, Zhang Zhijun Oct 2021

Medium Characteristics And Hydrodynamic Evolution Law Of High Salinity Mine Water Recharge In Deep Well, Liu Qi, Wang Weijun, Luo Bin, Wang Houzhu, Zhang Zhijun

Coal Geology & Exploration

The treatment and discharge of high salt mine water is one of the important factors affecting efficient coal mining in recent years. It is a worth exploring method to reduce the discharge of mine water by selecting the appropriate aquifer under the floor of the coal seam and transferring the high salt mine water to other places. Taking the X mine in the Ordos Basin as an example, the Baotashan sandstone and the deep Liujiagou Formation sandstone formation below the coal seam have transfer storage space. By mercury intrusion experiment and rock mechanics analysis, the two groups of formations were …

Go to article

Mine Water Drainage Pollution In China's Coal Mining Areas And The Construction Of Prevention And Control Technical System, Sun Yajun, Xu Zhimin, Li Xin, Zhang Li, Chen Ge, Zhao Xianming, Gao Yating, Liu Qi, Zhang Shangguo, Wang Weijun, Zhu Lulu, Wang Sheng Oct 2021

Mine Water Drainage Pollution In China's Coal Mining Areas And The Construction Of Prevention And Control Technical System, Sun Yajun, Xu Zhimin, Li Xin, Zhang Li, Chen Ge, Zhao Xianming, Gao Yating, Liu Qi, Zhang Shangguo, Wang Weijun, Zhu Lulu, Wang Sheng

Coal Geology & Exploration

Mining activities are bound to produce enormous mine water drainage. Mine water in China shows relatively poor water quality and high cost of water treatment and other problems. Firstly, the main characteristics of mine water quality in China's typical mine areas are clarified in this paper: conventional ions are the main chemical components causing poor mine water quality; mine water has a small proportion of toxic and harmful substances, which is generally better than the quality standard of class Ⅲ groundwater. Secondly, some scientific issues on the formation and evolution of mine water quality are discussed in detail, including the …

Go to article

Hydrochemical Characteristics And Genetic Mechanism Of High Tds Groundwater In Xinjulong Coal Mine, Zhang Yuzhuo, Xu Zhimin, Zhang Li, Lyu Weikui, Yuan Huiqing, Zhou Lijie, Gao Yating, Zhu Lulu Oct 2021

Hydrochemical Characteristics And Genetic Mechanism Of High Tds Groundwater In Xinjulong Coal Mine, Zhang Yuzhuo, Xu Zhimin, Zhang Li, Lyu Weikui, Yuan Huiqing, Zhou Lijie, Gao Yating, Zhu Lulu

Coal Geology & Exploration

Based on historical water quality data and sampling test results, using Piper three-line diagram, correlation analysis, hydrogen and oxygen isotope, Gibbs diagram, ion ratio and saturation index, etc., the hydrochemical characteristics and genetic mechanism of the groundwater with high TDS in Xinjulong Coal Mine area were explored. The results show that with the proceeding of mine construction and coal mining, the water chemistry environment in the study area has changed. The water chemistry type is no longer a single SO4-Na type, with SO4·HCO3-Na and SO4-Ca·Mg type appearing in the deep limestone water. …

Go to article

Gas Emission-Based Determination Of The Reasonable Driving Speed In Coal Roadway, Fu Shuai, Si Qingmin, Wang Qifei, Guo Xinyao, Zhang Hongtu Oct 2021

Gas Emission-Based Determination Of The Reasonable Driving Speed In Coal Roadway, Fu Shuai, Si Qingmin, Wang Qifei, Guo Xinyao, Zhang Hongtu

Coal Geology & Exploration

Scientific determination of the tunneling speed is an important prerequisite for the safe and efficient production in coal mines with high gas and outburst. In order to determine the reasonable driving speed of coal roadway and reduce the occurrence of dynamic disasters in coal roadway driving, the distribution law of gas in roadway head was analyzed, the mathematical model was established. Gas emission characteristics were also analyzed at different driving speeds based on the model. Taking Jinhui Wanfeng Coal Mine as an example, the reasonable driving speed was determined in this coal mine based on its gas emission characteristics. Results …

Go to article

Collapse Filling-Based Technology Of Weakening And Danger-Solving By Staged Fracturing In Hard Roof, Zheng Kaige, Yang Junzhe, Li Bingang, Li Yanjun, Dai Nan, Yang Huan Oct 2021

Collapse Filling-Based Technology Of Weakening And Danger-Solving By Staged Fracturing In Hard Roof, Zheng Kaige, Yang Junzhe, Li Bingang, Li Yanjun, Dai Nan, Yang Huan

Coal Geology & Exploration

The working face is easy to induce dynamic disasters such as rock burst, coal and gas outburst, mine earthquake and hurricane in goaf under the condition of hard roof, which seriously threatens the safety of mine production. the pre-weakening and risk-solving technology of staged fracturing in hard roof is proposed based on the mode of advanced weakening by staged fracturing through open holes, combined with the synergetic support concept with "fracturing collapse body+coal pillar+load-bearing rock layer". By using the methods of theoretical analysis, technical research and development and engineering application, the crisis mechanism of advanced weakening of the staged fracturing …

Go to article

De-Blocking Technology And Application Of High-Rank Cbm Well In Junlian Region In Sichuan Province, Peng Lisha, Zhang Yimin, Xiong Wei, Zhao Dan, Luo Kai Oct 2021

De-Blocking Technology And Application Of High-Rank Cbm Well In Junlian Region In Sichuan Province, Peng Lisha, Zhang Yimin, Xiong Wei, Zhao Dan, Luo Kai

Coal Geology & Exploration

The coal seams of Leping Formation in Junlian area are high-rank coal reservoir with low porosity and low permeability. The gas production of some coalbed methane wells decreases rapidly in the production process, which seriously restricts the benefit development of coalbed methane wells. Combined with the production data such as drainage, hydrochemistry and pump inspection, this paper analyzes the reasons for the decline of gas production. The main reasons for the decline are coal scaling and coal fines blockage. Targeted measures such as acid pickling, hydraulic shock, plasma pulse and water injection are carried out to remove the blockage. The …

Go to article

Discussion On Overburden Zoning Model After Mining And Its Engineering Significance, Lyu Yuguang, Qiao Wei, Cheng Jianyuan, Cui Ping Oct 2021

Discussion On Overburden Zoning Model After Mining And Its Engineering Significance, Lyu Yuguang, Qiao Wei, Cheng Jianyuan, Cui Ping

Coal Geology & Exploration

The mechanical state of overburden after mining is directly related to roof accidents and roof water disasters, so it is necessary to study the overburden structure after mining. The "New Four Zones" model of overburden structure is proposed: caving zone, fracture zone, bedrock separation zone and loose alluvium zone. Combined with the previous "Three Zones" model and "Four Zones" model, this paper makes a spatial comparative analysis to clarify the spatial relationship of the three zoning models. It discusses the scientific nature of the "New Four Zones" model in terms of the influence of mining on water level of the …

Go to article

Experimental Study On Visual System For Water-Blocking Process Of Hydrodynamic Roadway By Aggregate Pouring In Water Inrush Mine, Mou Lin Oct 2021

Experimental Study On Visual System For Water-Blocking Process Of Hydrodynamic Roadway By Aggregate Pouring In Water Inrush Mine, Mou Lin

Coal Geology & Exploration

Blocking water of hydrodynamic roadway by aggregate pouring in water inrush mines is an important method for mine rescue. To study its mechanism, the experimental platform of similar simulation test was established based on such factors as water head height, flow rate, roadway size, inclination angle, roughness, aggregate particle size and perfusion speed. Based on the platform, single-hole and multi-hole pouring tests were carried out to analyze the movement and accumulation law of aggregate in hydrodynamic pathway. The results are as follows. Firstly, the accumulation body has the characteristics of migration and growth to the downstream during the normal pouring …

Go to article

First Prev Next Last