Earth Sciences Commons^™

Management Of National Planned Coal Mining Areas And Discrimination With Coal Mining Areas, Wang Xiangsheng, Wang Meng, Liu Jingchun

Coal Geology & Exploration

In view of the confusion between national planned coal mining areas and coal mining areas, based on the relevant standards and notices, the definitions of national planned coal mining areas and coal mining areas are interpreted in detail. This paper introduces the basic situation of the first and second batches of national planned coal mining areas and the《National Mineral Resources Planning (2016-2020)》. The differences between the two are expounded in detail from the aspects of delineation purpose, delimitation basis and formation period. It is pointed out that the competent department of national planned coal mining areas is the Ministry of …

Research And Application Of Cbm Surface Extraction Based On Coal Mine With “Gas Drainage First, Construction Later” And Resource Development, Wang Jing, Yao Tuanqi, Cheng Bin

Coal Geology & Exploration

Aiming at the safety index put forward by "gas drainage first, construction later" of coal mine at present and the resource characteristics of many coal seams in northern Guizhou Province, and at the same time making up for the lack of systematization and large blind area of surface gas drainage deployment at present, this paper took Duijiangnan coal mine as an example to carry out the research of coal bed methane surface drainage deployment. Based on the complex topographic conditions, coal seam development characteristic(multiple layers, thin thickness, group distribution), coal body structure, development and deployment requirements in this area, the …

Influencing Factors Of Surface Gas Extraction Effect In Wangpo Minefield Of Jincheng Mining Area, Du Zhiqiang

Coal Geology & Exploration

The effect of surface gas extraction in Wangpo minefield of Jincheng mining area is poor. In order to find out the causes and to guide the construction of future surface gas extraction, the occurrence conditions of CBM resources in the study area were analyzed and compared with those of adjacent Chengzhuang minefield where the extraction effect is good, the quality of the produced water was tested, at the same time the fracture forms were observed underground. The comprehensive analysis indicated that the abundance of coal gas resources and the reservoir conditions were the major intrinsic basic factors influencing the gas …

Coal Control Factors Of Middle Jurassic Shimengou Formation In Beidatan Area, East Part Of The Northern Qaidam Basin, Peng Minghong, Tian Jingchun, Zhang Xiang, Chen Lei, Zeng Jianqiang, Wang Suying

Coal Geology & Exploration

The key of the coal exploration in Beidatan area of Qinghai Province is the coal accumulation environment in the sedimentary period and the control of coal seam occurrence by tectonic action before and after sedimentation. To identify Shimengou Formation coal controlling factors in Beidatan area, east part of the northern Qaidam basin, effectively guide the coal exploration of the coal bearing area, through field outcrops, drilling, geophysical prospecting and other geological information system, based on the analysis of coal accumulating environment and structural function of Shimengou Formation in Beidatan area, the control factors of coal were deeply discussed from coal …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Technology And Application Of Indirect Fracturing In Cbm Vertical Well Of Broken And Soft Coal Seam With Low Permeability, Zhou Jiajia

Coal Geology & Exploration

In order to solve the problems of pulverized coal output and fracturing fracture not easy to extend during fracturing operation in the broken and soft coal seam with low permeability, the adaptability and fracturing fracture distribution of CBM during indirect fracturing are studied by means of in-situ stress and numerical simulation, and the engineering practice of indirect fracturing has been tested in Hongshandian mining area of Hunan Province. The results show that indirect fracturing can effectively improve the fracturing effect of the broken and soft coal seam with low permeability, and increase the fracture length. When the roof and floor …

Coalbed Methane Migration Mechanism Under Adsorption-Desorption Condition In Coal, Liu Yongqian, Zhang Shulin, Shu Longyong

Coal Geology & Exploration

The migration law of coalbed methane(CBM) with adsorption has always been the focus of attention in the field of coalbed methane geology. In order to study the mechanism of CBM migration under adsorption-desorption state, the deduction of gas adsorption-desorption equation and theoretical analysis of gas diffusion-seepage in porous media were carried out, and new viewpoints were put forward by means of experimental analysis of CBM migration. The results identified that:(1) for the CBM migration, pore structure of coal body has the storage-resistance effect, the dual functions of gas storage and gas pressure drop form the basic feature of coal matrix, …

Occurrence Of Antimony In Magmatic Intrusive Coal Seam: A Case Study From The Wolonghu Coal Mine, Huaibei Coalfield, China, Ou Jinping, Zheng Liugen, Wei Xiangping, Liu Sikui, Li Liyuan, Liu Meng, Huang Xiaoyu

Coal Geology & Exploration

In order to investigate the influence of magmatic alteration on the occurrence characteristics of antimony in coal seam, 12 samples of magmatic magma and coal were collected from Wolonghu coal mine in Huaibei coalfield, Anhui Province, and the content of Sb was determined by atomic fluorescence spectrometry(AFS). The coal quality parameters are analyzed. The results are as follows:the coal in Wolonghu magmatic intrusion area has the characteristics of ultra-low volatile matter, medium ash content and ultra-low sulfur content. And the main forms of sulfur in coal are organic sulfur and pyrite sulfur. Under the influence of magmatic hydrothermal solution, ash …

Analysis Of Reservoir Conditions Of Shale Gas In Middle Permian Wenbishan Formation In Fujian Province, Chen Quanlin

Coal Geology & Exploration

This study is performed on the geological conditions of shale gas in Middle Permian Wenbishan Formation in Fujian Province. It is based on organic geochemistry, rock minerals and reservoir physical property after geology survey and drilling. The results indicate that kerogen is Ⅲ-type, organic carbon is usually between 1% to 2%, R_ran is between 3.76% to 4.91% in the shale of Wenbishan Formation, and the shale is in the mature stage. The content of brittle minerals is generally low. The shale has medium porosity and extremely low permeability, the micro and meso-pores constitute the major space for gas adsorption. …

Water Inflow Law Of The First Working Face Based On Water Pre-Draining From Roof, Li Yongtao, Yang Jian

Coal Geology & Exploration

In order to establish water control technology system in Inner Mongolia-Shaanxi contiguous area, we carried out some researches(e.g. overburden failure law, hydrogeological conditions, prediction of water inflow and pre-drainage of roof water) in Nalinhe No.2 coal mine. The results showed that three methods(i.e. coring, drilling fluid leakage observation and borehole color TV detection) were used to explore water-conducting fracture zone(103.23 m), and the ratio of the height of the fractured zone to the mining height was 18.8. Water-conducting fracture zone could connect three aquifers, and the Zhiluo Formation bottom aquifer was the main aquifer threatening safety mining. Water inflow and …

Microseismic Test And Numerical Simulation Analysis Of Floor Failure Depth Of Isolated Coal Mining Face, Zhao Chunhu

Coal Geology & Exploration

Aiming at the damage of coal seam floor caused by mining in isolated coal mining face, taking 11913 isolated coal mining face in Gequan coal mine of Hebei Province as the research object, and using KJ959 coal mine microseismic monitoring system to detect the floor failure depth. It is recognized that the microseismic events mainly occur in the roadway of the isolated coal mining face during the mining process, and the maximum vertical failure depth is about 20~25m; Moreover, using the COMSOL multi-physical field numerical simulation platform, the variation of in-situ stress and failure law of coal seam floor under …

Modification Function Of Magnetic Treatment On Grouting Clay Slurry, Xue Weifeng, Wang Sujian, Deng Zengshe, Huang Kejun, Han Lei, Ji Ruijun, Liang Shaojian

Coal Geology & Exploration

Clay slurry was treated through magnetization. The characteristics of the physical property change of the clay slurry after magnetic treatment such as viscosity, density, pH value, conductivity, syneresis rate, concretion rate and anti-permeability were studied. After magnetic treatment, density, viscosity and syneresis rate of the clay slurry decrease, pH, conductivity and concretion rate increase, the syneresis rate and the concretion rate are improved with the magnetization time. The magnetic treatment improves the rheological property of clay slurry, the anti-permeability performance of the cemented body of clay slurry after magnetic treatment rises greatly compared to the cemented body of clay slurry …

Inversion Analysis Of Earth Pressure For Limited Soil Between Oblique Support Retaining Foundation Pit And Adjacent Basement, Zhang Guomao, Peng Wenxiang

Coal Geology & Exploration

In order to study the distribution of earth pressure for limited soil between oblique support retaining foundation pit and adjacent basement, back analysis of site monitoring data of a foundation pit was studied. Based on the improved cubic spline method of the trial algorithm, Matlab software was used to calculate the bending moment value of the supporting structure and the earth pressure value behind the pile. The results show the earth pressure of limited soil is influenced by displacement mode, non-limit state and boundary conditions. The active earth pressure of limited soil above the excavation surface shows a distinct "R" …

Numerical Simulation On Mechanism Of Thrust Fault Reactivation During Mining, Min Feihu, Xiang Biwei, Liu Hui, Zhu Xiaojun

Coal Geology & Exploration

It is a hot issue in mine disaster research about the activation of faults during the process of coal mining and excavation. In order to reveal the influence of coal mining on fault activation under different fault dip conditions, Xinji No.2 mine in Huainan coalfield was taken as an example, and numerical simulation with FLAC^3D was used to systematically study the dynamic activation law of thrust faults during mining beside the faults, and to clarify the relationship among fault activation position and fault dip angle and excavated distance of working face. The results show that the fault activation is …

Application Of Seismic Exploration Technology In Forecasting Unconventional Gas Enrichment Area Of Coal Measures, Wang Shuwei

Coal Geology & Exploration

For forecasting unconventional gas enrichment area in coal measures of eastern Ordos basin, seismic exploration was used to forecast the gas in this new field. First of all, it took the post-stack impedance inversion to forecast the lithology of the reservoir, it can get the number of sample points from the impedance threshold, and get the thickness of time by cal-culating the sampling rate, after that it can get the strata thickness by multiplying the thickness of time and the velocities of strata; second, it took the pre-stack AVO inversion to forecast the lithology gas-bearing properties of the reservoir, based …

Constrained Inversion Method And Application Effect Of Tem Data Of Fixed Source Loop Device, Hou Yanwei, Yao Weihua

Coal Geology & Exploration

In order to eliminate the obvious framing effect after the TEM fixed source loop device increases the receiving area, to improve the delamination ability of TEM to enhance the fine resolution for different electrical strata, the regularization inversion method with constraint is adopted. In the inversion algorithm, the Lagrange factor is adjusted adaptively by CMD regularization factor. In order to ensure the efficiency, stability and convergence of the results of the inversion process, the thickness of each layer of the inversion model is discretized according to the equal logarithmic interval, and the ill conditioned property of the matrix equation is …

Experimental Study And Economic Evaluation Of Low Temperature Drying Treatment Of Abandoned Water-Based Drilling Fluid, Li Zhijun, Liu Xusan, Wang Bo, Zhao Wei

Coal Geology & Exploration

Abandoned water-based drilling fluids are the waste of oil drilling engineering operations. It will not only keep the cost of drilling fluid high, but also have a very adverse impact on the environment if it is directly discharged. Reusing of abandoned water-based drilling fluid after low-temperature drying treatment is one of treatment methods which is economic and conforms to the modern development trend. In this paper, the experimental study and economic evaluation of the low-temperature drying technology of polymer drilling fluid system, sulfonated drilling fluid system and Sichuan shale gas well drilling fluid system were conducted. The results show that …

Instability Mechanism And Anti-Sloughing Drilling Fluid Technique For Deep Coal Seam Of Tarim Basin, Li Heng, He Shiming, Tang Ming, Li Ning, Yang Pei, Zhang Zhen

Coal Geology & Exploration

In view of the complicated problems of drilling fluid leakage and hole collapse during the drilling of deep coalbed in Tarim basin, the microstructure and physical and chemical properties of coal were tested by vitrinite reflectance analysis, X ray diffraction and scanning electron microscope, and the mechanism of coal seam instability was confirmed. The fixed carbon content of the coal exceeds 60%, the vitrinite reflectance is greater than 1.1%, and coal have high degree of coalification, is brittle and easy to break. The total amount of clay mineral is less than 25%, and there is no strong water-sensitive mineral montmorillonite …

Study On Slope Stability And The Effect Of Highfill On The Mechanical Properties Of Red Clay Foundation, Gao Shengxiang, Xu Qiang, Ma Hongyu, Wu Shenglin, Wu Kang, Liu Peng, Wu Zehui

Coal Geology & Exploration

This paper takes a highfill slope in Anning in Yunnan Province as a case, using investigation, monitoring and other methods, on the basis of the distribution characteristics of red clay, the physical and mechanical properties of red clay before and after filling were analyzed, then the stability of slope was studied by numerical simulation software. The results show that the physical and mechanical indexes of the red clay foundation decrease first and then increase before and after the fill project, the stability of the fill slope shows the trend of decrease first and then increase. The ground fissures in the …

A Pipeline Robot Detection Image Enhancement Method Based On Image Fusion And Improved Threshold, Yuan Mingdao, Tan Cai, Li Yang, Xu Yunqian, Zhang Xuhui, Yang Jingxue

Coal Geology & Exploration

Pipeline robot detection technology can quickly, accurately and intuitively identify the structure and hidden functional troubles of pipeline. However, due to the restriction of the pipeline environment, the detected images have problems such as uneven illumination, low contrast and blurred details. Therefore, an enhancement technique for detected image of pipeline robot is proposed. First, the contrast limited adaptive histogram equalization(CLAHE) and homomorphic filtrate(HF) are applied to deal with the problem of uneven illumination and low contrast, and the result images of the two methods are fused. Secondly, the fusion images are transformed by the Nonsubsampled Contourlet Transform(NSCT), and the improved …

Detection Accuracy Analysis Of Tsp And Its Application In A River-Crossing Tunnel Construction, Li Junjie, Zhang Honggang, He Jianshe, Rong Xin, Li Jianqiang, Guo Jiahao

Coal Geology & Exploration

Aiming at the problems of TSP such as long detection time and strong experience-depending, in order to improve the accuracy and the efficiency of TSP detection, we analyzed the key factors which affect data acquisition and processing accuracy of TSP and summarized the experiences of improving the detection efficiency of TSP. In combination with the TSP advanced geological prediction work in a river-crossing tunnel for water distribution project in Qiandaohu lake, the TSP tracing prediction or GPR detection in the area where the TSP resolution decreases were carried out and the geophysical abnormal area was verified by drilling. The results …

Modeling Irrigation Behavior In Groundwater Systems, Timothy Foster, Nicholas Brozovic, Adrian P. Butler

Daugherty Water for Food Global Institute: Faculty Publications

Integrated hydro-economic models have been widely applied to water management problems in regions of intensive groundwater-fed irrigation. However, policy interpretations may be limited as most existing models do not explicitly consider two important aspects of observed irrigation decision making, namely the limits on instantaneous irrigation rates imposed by well yield and the intraseasonal structure of irrigation planning. We develop a new modeling approach for determining irrigation demand that is based on observed farmer behavior and captures the impacts on production and water use of both well yield and climate. Through a case study of irrigated corn production in the Texas …

Water Productivity In Meat And Milk Production In The Us From 1960 To 2016, Mesfin Mekonnen, C.M.U. Neale, Chittaranjan Ray, Galen E. Erickson, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Global demand for livestock products is rising, resulting in a growing demand for feed and potentially burdening freshwater resources to produce this feed. To offset this increased pressure on water resources, the environmental performance of livestock sector should continue to improve. Over the last few decades, product output per animal and feedstuff yields in the US have improved, but before now it was unclear to what extent these improvements influenced the water productivity (WP) of the livestock products. In this research, we estimate changes in WP of animal products from 1960 to 2016. We consider feed conversion ratios (dry matter …

Perchlorate Behavior In The Context Of Black Carbon And Metal Cogeneration Following Fireworks Emission At Oak Lake, Lincoln, Nebraska, Usa, Manish Kumar, Daniel D. Snow, Yusong Li, Patrick Shea

Nebraska Water Center: Faculty Publications

The imprints of fireworks displays on the adjacent water body were investigated from the perspective of cogeneration of black carbon, metals and perchlorate (ClO₄^–). In particular, the mixing and dissipation of ClO₄^– were studied at Oak Lake, Lincoln, Nebraska, following fireworks displays in 2015 and 2016. Following the display, ClO₄^– concentration in the water increased up to 4.3 μg/L and 4.0 μg/L in 2015 and 2016, respectively. A first-order model generally provided a good fit to the measured perchlorate concentrations from which the rate of dissipation was estimated as 0.07 d^–1 in …

Evaluating Future Reservoir Storage In The Rio Grande Using Normalized Climate Projections And A Water Balance Model, Nolan T. Townsend

Earth and Planetary Sciences ETDs

We develop and implement new tools for assessing the future of surface water supplies in downstream reaches of the Rio Grande, for which Elephant Butte Reservoir is the major storage reservoir. First, a normalization procedure is developed to adjust natural Rio Grande streamflows simulated by dynamical models in downstream reaches. The normalization accounts for upstream anthropogenic impairments to flow that are not considered in the model, thereby yielding downstream flows closer to observed values and more appropriate for use in assessments of future flows in downstream reaches. The normalization is applied to assess the potential effects of climate change on …

Breakdown Mechanisms In Iron Caves. An Example From Brazil, Marcelo R. Barbosa, Allan D.F. Da Silva, Rafael G. De Paula, Georgete M. Dutra, Airton Barata, Iuri V. Brandi, Chrystophe R.P. Da Silva, Robert A. Osborne

International Journal of Speleology

An iron cave in the vicinity of a mine in Carajás, Brazil, was selected to be mined within an assisted elimination project, planned to control all mine advancement operations towards the cave along with a strict speleological physical monitoring. It allowed, in a pioneering way, the recording of events in the cave from the first signs of damage until to the total collapse of the cave. The project lasted four years and it was possible to identify and describe four breakdown mechanisms in iron caves: Fragment downfall, Block downfall, Controlling structure reactivation, and Open discontinuity movement. The mechanisms occurred independently …

Crop And Climate Suitability For Irrigated Agriculture In The Midlands Area Of Western Australia, 2nd Edition, Leon Van Wyk

Resource management technical reports

The Midlands groundwater and land assessment is a $4.7 million Water for Food project. Its aim is to confirm groundwater availability at one or more focus areas that may form precincts of 2000–3000 hectares suitable for intensive irrigated horticulture. This report forms part of this project.

Firstly, this report describes the climate of the Midlands study area and highlights the subtle differences between the two selected focus areas, Irwin and Dinner Hill. It discusses the importance of climate in determining crop suitability. We also investigated the following additional factors that determine crop suitability: water quality, water quantity, land capability (soils) …

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- July 2019, Natalie Umphlett, Rezaul Mamood, Paul Flanagan, Emily Brown, Gannon Rush, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the director........................................1

Staff spotlight...........................1

Spirit Lake workshop..............2

Product highlight....................3

Outreach events......................3

Research highlight..................4

Update on regional climate conditions..................................4

Northern Plains drought assessment................................5

Recent and upcoming travel and activities.............................6

Droughtscape, Fall 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Quarterly drought summary

Quarterly drought impacts

Ranchers delayed response to drought

Drought Monitor celebrates 20 years

Drought Monitor state impact tables

Directorcontributesto U.N.droughtproject

Updated Drought Risk Atlas

New fact sheet lists recovery resources

Droughtscape, Summer 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Quarterly drought summary

Quarterly drought impacts

NDMC welcomes African visitors

Ready for Drought game debuts

U.S. Virgin Islands added to USDM

Australian programmer visits NDMC

Upcoming events

Partnerships with NDMC extended