Origin and Spacing of Cleats in Coal Beds

1977 ◽  
Vol 99 (4) ◽  
pp. 624-626 ◽  
Author(s):  
F. T. C. Ting
Keyword(s):  
Bituminous Coal ◽  
Coal Bed ◽  
Coal Rank ◽  
Upper Crust ◽  
Coal Seams ◽  
Petrographic Composition ◽  
Coal Beds ◽  
Bedding Planes ◽  
Two Parameters ◽  
Roof Support

Cleats are natural fractures in coal beds resulting from dehydration, devolatilization, and stresses in the earth’s upper crust during coalification. The orientation of these fractures usually parallels that of the fractures (joints) in the associated rocks except that the former is better developed. Spacing of cleats ranges from less than one millimeter to over one meter. The frequency of cleating in coal beds affects not only mining but also the flow of gases in the coal, and the strength of pillars used for roof support. The variation in spacing in controlled primarily by two parameters, namely rank and petrographic composition of the coal. The cleat frequency increases with increasing rank and reaches a maximum at the low-volatile bituminous coal rank. Within the same coal bed at the same mine face, dull coal layers tend to have fewer cleats than bright coal layers. The nature of the cleats is further complicated by local disturbances such as faults, folds, and fissility of bedding planes in the coal seams.

Research on Main Control Factors of Coalbed Methane Reservoir Formation in Turpan-Hami Basin

2011 ◽  
Vol 233-235 ◽  
pp. 2201-2204 ◽  
Author(s):  
Gui Zhong Li ◽  
Hong Yan Xu ◽  
Bo Wang ◽  
Ze Deng ◽  
Meng Geng
Keyword(s):  
Coalbed Methane ◽  
Structural Evolution ◽  
Coal Bed ◽  
Coal Rank ◽  
Hydrogeological Condition ◽  
Gas Reservoirs ◽  
Coal Resources ◽  
Coal Beds ◽  
Control Factors ◽  
Coalbed Methane Reservoir

Turpan-Hami Basin is a typical low coal rank coal bearing basin in China, with coal resources accounting for 50% of the total low coal rank resources. Structural evolution of the basin plays important controlling roles to generation；Fan delta and braided delta deposit systems are thick and stable sedimentary systems which are favorable for coal beds development；Hydrogeological condition is a major force for the adjustment and construction of coal-bed gas reservoirs.

Research on coal metamorphic patterns in main minable coal-beds of longdong mine field in Xingtai

2013 ◽  
Vol 10 (4) ◽  
pp. 381-386 ◽  
Author(s):  
Yingbin Guan ◽  
Chanyu Guo ◽  
Haimei Li
Keyword(s):  
Regional Metamorphism ◽  
Coal Bed ◽  
Coal Seams ◽  
Coking Coal ◽  
Mine Field ◽  
Coal Gas ◽  
Thermal Metamorphism ◽  
Coal Beds ◽  
Lean Coal ◽  
Coal Resource

The coal-bearing strata of Longdong mine field in Xingtai is the Carboniferous-Permian. The No.8 coal seam is located in the Taiyuan formation and is the main minable coal-bed. The coal is mainly gas-fat coal accompanied with coking coal, lean coal and anthracite. The results of the macroanalysis and maceral quantitative analysis on the main minable coal-bed show that the degree of coal metamorphism takes the old town as the center and is distributed concentrically outward and the anthracite and lean coal are distributed nearby the old town, and the coal gradually becomes coking coal, gas-fat coal and gas coal further outwards. The degree of coal metamorphism was affected by regional metamorphism, and the coal seams which are close to the old town stack the regional magmatic thermal metamorphism. The conclusions of the research offer a scientific foundation to exploit the coal resource in this area?

Using HEM surveys to evaluate disposal of by-product water from CBNG development in the Powder River Basin, Wyoming

Geophysics ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. B77-B84 ◽  
Author(s):  
Brian A. Lipinski ◽  
James I. Sams ◽  
Bruce D. Smith ◽  
William Harbert
Keyword(s):  
River Basin ◽  
Produced Water ◽  
Water Discharge ◽  
Geophysical Methods ◽  
Powder River Basin ◽  
Coal Bed ◽  
Coal Beds ◽  
Occam’S Inversion ◽  
Product Water ◽  
Location Strategies

Production of methane from thick, extensive coal beds in the Powder River Basin of Wyoming has created water management issues. Since development began in 1997, more than 650 billion liters of water have been produced from approximately 22,000 wells. Infiltration impoundments are used widely to dispose of by-product water from coal bed natural gas (CBNG) production, but their hydrogeologic effects are poorly understood. Helicopter electromagnetic surveys (HEM) were completed in July 2003 and July 2004 to characterize the hydrogeology of an alluvial aquifer along the Powder River. The aquifer is receiving CBNG produced water discharge from infiltration impoundments. HEM data were subjected to Occam’s inversion algorithms to determine the aquifer bulk conductivity, which was then correlated towater salinity using site-specific sampling results. The HEM data provided high-resolution images of salinity levels in the aquifer, a result not attainable using traditional sampling methods. Interpretation of these images reveals clearly the produced water influence on aquifer water quality. Potential shortfalls to this method occur where there is no significant contrast in aquifer salinity and infiltrating produced water salinity and where there might be significant changes in aquifer lithology. Despite these limitations, airborne geophysical methods can provide a broadscale (watershed-scale) tool to evaluate CBNG water disposal, especially in areas where field-based investigations are logistically prohibitive. This research has implications for design and location strategies of future CBNG water surface disposal facilities within the Powder River Basin.

scholarly journals Comparative characteristics of the petrographic composition and quality of coal series С12 and С13 of the Prydniporovia Block

2021 ◽  
Vol 30 (1) ◽  
pp. 145-152
Author(s):  
Vyacheslav S. Savchuk ◽  
Vasyl F. Prykhodchenko ◽  
Dmytro V. Prykhodchenko ◽  
Valeriia V. Tykhonenko
Keyword(s):  
Volatile Matter ◽  
Matter Content ◽  
Coal Seams ◽  
Combustion Heat ◽  
Petrographic Composition ◽  
Genetic Features ◽  
History Of ◽  
Coal Composition ◽  
Technological Indices

Taking into consideration the whole history of geological development of the Western Donbas, data on composition and grade of С12 series coal involved information about the geotectonic development of the Basin. To satisfy the objectives, a system of research methods, covering petrographic, computational, statistical, chronological, comparative and other methods, has been applied. In the process of identification of the petrographic composition and grade of series С12coal on the territory of the Prydniprovia Block, and determination of lateral regularities of their change as well as change in stratigraphic section of the Lower Carboniferous, data of petrographic as well as chemical and technological indices of the coal seam c1 were generalized along with data of all seams of С13 series. The activities helped define genetic features of series С12coal as well as stratigraphic and lateral regularities of changes in the coal composition. The differences in the petrographic composition as well as in the chemical and technological characteristics of series С12 and С13 are indicative of dissimilar conditions of formation of their peat depositions. It has been determined that compared with С13 series coal, the coal of С12 series contains more humidity and fewer mineral impurities. It is characterized by higher values of sulfur content, volatile-matter content, and combustion heat. The ultimate composition of coal seams of С12series is characterized by smaller values of carbon and oxygen contents as well as greater hydrogen content. The conclusions on common features and differences in the petrographic composition as well as chemical and technological features of coal seams of С12and С13 series, and regularities of their changes over the area of the seam occurrence was assessed.

scholarly journals The Variability of Mercury Content in Bituminous Coal Seams in the Coal Basins in Poland

Resources ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 127
Author(s):  
Justyna Auguścik-Górajek ◽  
Marek Nieć
Keyword(s):  
Coal Combustion ◽  
Bituminous Coal ◽  
Mercury Content ◽  
Limited Extent ◽  
Iron Sulfides ◽  
Coal Seams ◽  
Preliminary Assessment ◽  
Coal Basin ◽  
Coal Quality ◽  
Mercury Emission

The mercury content in bituminous coal in Poland varies depending on the coal basin. The highest of its concentrations are recorded in the Lower Silesian Coal Basin where this may be the result of the volcanic activity reported there. A much lower average of Hg content was recorded in Lublin and the Upper Silesian Coal Basins (LCB and USCB), although it was higher in the former. A higher mercury concentration in the LCB is probably related to the zone of supposed deep disturbances, named the Karpinsky lineament. Most published works present the data on the mercury content in the bulk of mined coal. The preliminary assessment of mercury content in coal seams indicates that it varies considerably between and within them. It is bound to the presence of arsenic-bearing iron sulfides. Concentration of mercury in small zones of limited extent suggests it was introduced by migrating fluids. The knowledge of mercury content distribution in coal seams would improve the prediction of its content in the mined coal and allow better management of produced coal quality with the aim of reducing mercury emission to the atmosphere as a result of coal combustion.

scholarly journals Effect of flow rates of gases flowing through a coal bed during coal heating and cooling on concentrations of gases emitted and fire hazard assessment

2019 ◽  
Vol 7 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Marek Więckowski ◽  
Natalia Howaniec ◽  
Adam Smoliński
Keyword(s):  
Fire Hazard ◽  
The Self ◽  
Coal Bed ◽  
Flow Rates ◽  
Coal Beds ◽  
Heating And Cooling ◽  
Heating Phase ◽  
Two Samples ◽  
Cooling Phase ◽  
Phase Temperature

AbstractThe flow velocity of gases in gobs directly influences the kinetics and intensity of gaseous components release during heating and cooling of coal. The assessment of fire hazard is performed on the basis of concentrations of particular gases in a mine air. These concentrations differ in coal heating and cooling phase which was proven in the study. This paper presented the results of the experimental study on temperature distribution in a simulated coal bed in heating (50–250 °C) and cooling (250–35 °C) phases as well as its correlation to variations in concentration of gases released in these phases and flow rates of gases flowing through the coal bed. The research was performed on twenty-two samples of bituminous coals acquired from various coal beds of Polish coal mines. Considerable differences were observed between heating and cooling phases in terms of the concentrations of gases taken into account in calculations of self-combustion index. In the heating phase temperature increase resulted in the decrease of concentrations ratios of ethane, ethylene, propane, propylene and acetylene, while in the cooling phase these ratios increased systemically. The effect of air (in heating phase) and nitrogen (in cooling phase) flow rate on the self-ignition index CO/CO2 was also determined.

Recovering coal bed methane from deep unmineable coal seams and carbon sequestration

2007 ◽  
Vol 29 (4) ◽  
pp. 474 ◽  
Author(s):  
Thomas D. Brown ◽  
Donald K. Harrison ◽  
J. Richard Jones ◽  
Kenneth A. LaSota
Keyword(s):  
Carbon Sequestration ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Coal Seams

The Studies on Gas-Bearing Characteristics of Deep Coal Seams in Yanchang Oil and Gas Province, China

2014 ◽  
Vol 962-965 ◽  
pp. 213-216
Author(s):  
Guo Ping Jiang
Keyword(s):  
Coal Seam ◽  
Layer Thickness ◽  
Oil And Gas ◽  
Single Layer ◽  
Gas Content ◽  
Coal Bed ◽  
Coal Seams ◽  
Resource Potential ◽  
Gas Bearing ◽  
Average Layer Thickness

In this paper, four general directions are described to make evaluations and their resource potential; those are coal structure and coal level, gas content of deep coalbed, the coalbed thickness and distribution and the buried depth of coalbed. Coalfields of the study area are mainly Permian and Carboniferous coal seam of Shanxi Formation coal and Benxi group 11 # coal, coal seam depth 1370-1812m. No. 3 coal-seam average layer thickness of 1.6 m, the monolayer most 2 m thick; No. 11 coal-seam in the average layer thickness of 3 m, single-layer thickness of 4.5 m. Predict the amount of coal resources of 17.3 one hundred million t. Predict coal-bed methane resources of 27.68 billion cubic reserve abundance of 104 million square / km2 in. The exploration results show that this region has good development prospects.

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