The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Slawomir Kedzior - One of the best experts on this subject based on the ideXlab platform.
-
methane contents and Coal rank variability in the upper silesian Coal Basin poland
International Journal of Coal Geology, 2015Co-Authors: Slawomir KedziorAbstract:Abstract The process of Coalification results in changes in both the chemical composition and physical properties of the Coal. One of the most important stages in the development of bituminous Coal is the so called “second Coalification jump” corresponding to medium-volatile Coals characterized by a significant decrease of volatile matter from 33% to 20% and the release of methane, carbon dioxide and water. In the Upper Silesian Coal Basin (USCB), the highest values of methane content (> 12–14 m 3 /t Coal daf) range from 35–22% (V daf ) and vitrinite reflectance (R r ) values from 0.84–1.50% range—in approximate accord with values defining the second Coalification jump (V daf —29%; R r —1.3%), i.e., coking Coals. In the Basin, the distribution of the top of high methane zone (4.5 m 3 /t Coal daf) is similar to that of the coking Coals. That is why increasing methane contents towards the southern- and western parts of the Basin can be explained by the increasing proportion of coking Coals there. However, on a Basin scale, correlations between present methane contents and individual parameters of Coal rank are weak due, most likely, to late gas migration due, in turn, to factors unrelated to earlier Coalification including, inter alia, tectonic disturbance and hydrodynamic processes.
-
reservoir parameters and maceral composition of Coal in different carboniferous lithostratigraphical series of the upper silesian Coal Basin poland
International Journal of Coal Geology, 2013Co-Authors: Slawomir Kedzior, Iwona JelonekAbstract:Abstract Laboratory tests were carried out on Coal samples taken from mine openings of selected Coal mines in the Upper Silesian Coal Basin. The analyses involved maceral composition (vitrinite, inertinite and liptinite group) and vitrinite reflectance on the one hand, and reservoir parameters (Coal permeability and effective porosity) on the other. The results are compared. Samples with high values of Coal permeability are characterized by vitrinite contents of ca 60%, and samples with the lowest permeability by vitrinite contents of 40%. The vitrinite-rich bright Coals are brittle and prone to crushing caused by tectonic pressures. Moreover, Coal permeability is more strongly anisotropic in the bright Coals of the Cracow Sandstone and the Mudstone Series than in the dull Coals of the Upper Silesian Sandstone Series. In bright Coals, permeability is much along the direction parallel to vitrain layers. Good reservoir parameters such as permeability and effective porosity are crucial for fluid flow through the Coal seams and, thus, successful Coalbed methane exploitation. In the Upper Silesian Coal Basin, Cracow Sandstone- and Mudstone Series with vitrinite-rich Coals should be a good target, though serious geological problems must first be overcome.
-
geology spatial distribution of methane content and origin of Coalbed gases in upper carboniferous upper mississippian and pennsylvanian strata in the south eastern part of the upper silesian Coal Basin poland
International Journal of Coal Geology, 2013Co-Authors: Slawomir Kedzior, Maciej J Kotarba, Zbigniew PekalaAbstract:Abstract The subject of the investigation was both vertical and horizontal distribution of methane content in Coal series within the south-eastern part of the Upper Silesian Coal Basin. In the study area Coal deposits are characterized by various methane structures and varied spatial distribution of methane. “Brzeszcze” Coal deposit located in the upthrow of Jawiszowice fault zone represents the so-called “open” methane pattern, in which the upper parts of Coal-bearing series, to the depth of 300–500 m (seam 327), are naturally degassed. Beneath, methane content rapidly increases with depth, and often achieves high values (between ten and twenty m 3 CH 4 /Mg Coal daf). The area located to the south of Jawiszowice fault zone represents the so-called “closed” methane pattern, which means, that the primary methane zone was reworked due to the forming of Carpathian Foredeep in the Miocene period. A thick cover of Miocene claystones overlying the Carboniferous formations favors gas accumulation in the uppermost parts of the Carboniferous Coal-bearing complex, especially in the roof elevations. Free methane occurs within the elevated part of porous and permeable Łaziska sandstones covered by Miocene claystones. The highest methane content characterizes the Coal seams, which lie within Mudstone or Upper Silesian Sandstone Series. Smaller methane content is typical of the seams lying within Łaziska sandstones. The fault tectonics is another factor influencing the distribution of methane content, therefore, the large-size dislocations i.e. Jawiszowice and Bzie–Czechowice fault zones move the high-methane Coal seams according to throw direction – southwards. The Carboniferous lithology, fault tectonics and also Miocene claystones covering the Carboniferous formations are the crucial factors influencing the various methane contents in the area discussed. Methane – the main component of gases accumulated in Coal deposits and the minor components such as ethane, propane, butanes and carbon dioxide are of thermogenic origin that resulted from Variscan Coalification, whereas the methane of the secondary accumulation in the uppermost part of Carboniferous formations beneath the impermeable Miocene cover contains a large microbial component, which is a result of Paleocene infiltration of meteoric waters with nutrients for methane bacteria into the Coal series.
-
the occurrence of a secondary zone of Coal bed methane in the southern part of the upper silesian Coal Basin southern poland potential for methane exploitation
International Journal of Coal Geology, 2011Co-Authors: Slawomir KedziorAbstract:Abstract Coal-bed methane (CBM) exploitation in the Upper Silesian Coal Basin has, in spite of earlier failures, again aroused investor interest. Carboniferous Coal seams at depths of 200–500 m are characterized by Coal permeability values (estimated at 27–230 mD) and degrees of methane saturation (almost 100%) that suggest future successful exploitation. Based on the results of geological surveys archived in the Polish Geological Institute, the shallow CBM zone is defined as a gas horizon distinct from a deep CBM zone. The disposition of the shallow zone follows the topography of the Upper Carboniferous paleorelief, and, is deemed the most important factor controlling methane distribution within this zone. The most favorable places for CBM accumulation within the shallow Coal seams are erosional highs and the slopes of Upper Carboniferous ridges associated with fault zones. The thickness of the zone (> 200 m) and methane contents (> 8 m 3 /t Coal daf) are highest in these places. The nearly-full saturation of the Coal seams with methane reflects the involvement of two genetic types of gas — indigenous late-stage microbial methane and thermogenic methane derived from the deeper Coals. The favorable geological characteristic of this shallow CBM zone is a potential source of energy for Upper Silesia.
-
accumulation of Coal bed methane in the south west part of the upper silesian Coal Basin southern poland
International Journal of Coal Geology, 2009Co-Authors: Slawomir KedziorAbstract:Abstract The archives of the Polish Geological Institute house a wealth of Coal-bed methane (CBM) data from surface boreholes and excavations in Coal from the deposits of the Upper Silesian Coal Basin (USCB). These data support a model for the origin of substantial methane accumulations in the south-west part of the Basin that reflects the interplay of the factors controlling methane sorption capacity and those controlling methane content. The factors controlling the sorption capacity of Coal include Coal rank, temperature, pressure, moisture content and maceral composition. Methane-content controls include lithology, stratigraphy, tectonics, hydrogeology and mining activity. The nature of the Coal-bearing Carboniferous horizons, the sorption/desorption properties of the Coals, the disposition of faults and folds, the topography of the Carboniferous palaeosurface and the presence of an impermeable Miocene cover were key controls. The methane accumulated in Coal seams and in their host rocks in settings comparable with those in which petroleum and gas deposits are trapped.
Barbara Kwiecinska - One of the best experts on this subject based on the ideXlab platform.
-
facies analysis of Coal seams from the cracow sandstone series of the upper silesia Coal Basin poland
International Journal of Coal Geology, 2002Co-Authors: Dariusz Gmur, Barbara KwiecinskaAbstract:Abstract The main purpose of this study was to recognise the variability of petrographical structure of two Coal seams occurring in the Cracow Sandstone Series (Upper Carboniferous/Pennsylvanian, Upper Westphalian), being exploited in the Siersza mine. This mine is located in the eastern part of the Upper Silesia Coal Basin (USCB). The chemical analyses and petrographical features allow the inclusion of these Coals to the group of hard brown Coals belonging to subbituminous class. Two Coal seams (207 and 209/210) of a considerable thickness (7.44 and 6.54 m, respectively), representative of the Cracow Sandstone Series (CSS), were chosen for the petrographic studies. Dominant macroscopic constituents of both seams are banded bright Coal and banded Coal. The Coal seams were sampled in 284 intervals using a channel profile sampling strategy. The microscopical examinations revealed the majority of macerals from the vitrinite group (55%), followed by inertinite (21%), liptinite (11%), and mineral matter (13%). Low values of the vitrinite reflectance ( R o =0.46%) confirm very low Coalification of the Coal in both seams. Facies analysis indicates that in the course of a mire development, in which the studied Coal seams originated, wet forest swamp conditions dominated characterized by a high degree of flooding and gelification as well as by a prevalence of arborescent plants. In such conditions, lithotypes with a large content of bright Coal were mainly formed. Petrographic and facies data point to the rheotrophic character of these peatbogs. Frequent changes of the conditions in the peatbog, as it is shown by the variability of petrographic structure of the studied profiles, as well as by lateral changes of the phytogenic sedimentary environment within the Coal seams, indicate a strong influence of a river channel on the adjoining peatbogs. An accretion of clastic sediments within the wide river channel belts was balanced mainly by the peatbog growth on the areas outside channels. Frequency and rate of avulsion of the river channels influenced the size, continuity and variability of the peatbogs.
H S Duzgun - One of the best experts on this subject based on the ideXlab platform.
-
analysis of roof fall hazards and risk assessment for zonguldak Coal Basin underground mines
International Journal of Coal Geology, 2005Co-Authors: H S DuzgunAbstract:The roof fall hazards are frequent problems of underground Coal mines, which are generally unpredictable due to the associated uncertainties. These uncertainties, which arise from geological and stress conditions and mine environment, make the control of roof fall hazards difficult in underground Coal mines. The most efficient method for coping with uncertainties in roof fall hazards is the use of risk assessment techniques. In this study, a risk assessment and management methodology is proposed for roof fall hazards in underground mines of the Zonguldak Coal Basin. The annual rates of roof falls obtained from the five mines in the Basin are statistically analyzed. The components of risk, which are the probability of roof fall and consequences of roof fall hazard are identified and quantified. The probability of roof fall is computed by fitting a distribution function to the annual roof fall, while the consequences of roof falls are quantified based on a cost model. Then a decision analysis methodology for evaluating the performance of possible alternative action to be taken in order to decrease the risk, is developed. The results show that the underground Coal mines in the Zonguldak Coal Basin have considerably high risk levels and hence require comprehensive risk management schemes.
Karolina Owczarz - One of the best experts on this subject based on the ideXlab platform.
-
evolution of secondary deformations captured by satellite radar interferometry case study of an abandoned Coal Basin in sw poland
Sustainability, 2019Co-Authors: Jan Blachowski, Anna Kopec, Wojciech Milczarek, Karolina OwczarzAbstract:The issue of monitoring surface motions in post-mining areas in Europe is important due to the fact that a significant number of post-mining areas lie in highly-urbanized and densely-populated regions. Examples can be found in: Belgium, the Czech Republic, France, Germany, the Netherlands, Spain, the United Kingdom, as well as the subject of this study, the Polish Walbrzych Hard Coal Basin. Studies of abandoned Coal fields show that surface deformations in post-mining areas occur even several dozen years after the end of underground Coal extraction, posing a threat to new development of these areas. In the case of the Walbrzych area, fragmentary, geodetic measurements indicate activity of the surface in the post-mining period (from 1995 onward). In this work, we aimed at determining the evolution of surface deformations in time during the first 15 years after the end of mining, i.e., the 1995–2010 period using ERS 1/2 and Envisat satellite radar data. Satellite radar data from European Space Agency missions are the only source of information on historical surface movements and provide spatial coverage of the entirety of the Coal fields. In addition, we attempted to analyze the relationship of the ground deformations with hydrogeological changes and geological and mining data. Three distinct stages of ground movements were identified in the study. The ground motions (LOS (Line Of Sight)) determined with the PSInSAR (Persistent Scatterer Interferometry) method indicate uplift of the surface of up to +8 mm/a in the first period (until 2002). The extent and rate of this motion was congruent with the process of underground water table restoration in separate water Basins associated with three neighboring Coal fields. In the second period, after the stabilization of the underground water table, the surface remained active, as indicated by local subsidence (up to −5 mm/a) and uplift (up to +5 mm/a) zones. We hypothesize that this surface activity is the result of ground reaction disturbed by long-term shallow and deep mining. The third stage is characterized by gradual stabilization and decreasing deformations of the surface. The results accentuate the complexity of ground motion processes in post-mining areas, the advantages of the satellite radar technique for historical studies, and provide information for authorities responsible for new development of such areas, e.g., regarding potential flood zones caused by restoration of groundwater table in subsided areas.
Olgay Yarali - One of the best experts on this subject based on the ideXlab platform.
-
investigation into relationships between cerchar hardness index and some mechanical properties of Coal measure rocks
Geotechnical and Geological Engineering, 2017Co-Authors: Olgay YaraliAbstract:This paper examines the relationships between Cerchar hardness index (CHI) and some mechanical properties of Coal measure rocks in Zonguldak Hard Coal Basin. Some index properties (Cerchar hardness index, Shore scleroscope hardness, in situ Schmidt rebound hardness and point load strength) and strength (uniaxial compressive strength and Brazilian tensile strength) properties of 29 sedimentary rock samples are determined. Then, relationships between (CHI) and strength as well as and some other index values are evaluated using statistical methods. Linear relationships are found between CHI and uniaxial compressive strength, Schmidt rebound hardness. Power relationships are determined between CHI and Shore scleroscope hardness, diametral point load strength, point load strength anisotropy index. Besides, CHI tests are performed by means of bits having tip angles of 99° and 125° and excellent linear relationships are identified between them.
-
investigation of the effect into mechanical properties of rocks on cerchar abrasivity index
Karaelmas Science and Engineering Journal, 2016Co-Authors: Olgay YaraliAbstract:In this study, the relationships between abrasiveness and some mechanical properties of Coal measures rocks in Zonguldak Hard Coal Basin were investigated. For this purpose, Cerchar abrasivity (CAI), index (Shore scleroscope hardness, and point load strength) and strength (uniaxial compressive strength and Brazilian tensile strength) tests were carried out on 29 sedimentary rock samples. Then, relationships among CAI and strength, index test values were evaluated using regression analysis and statistical methods. As a result, positive linear relationships were found among CAI and uniaxial compressive strength, Brazilian tensile strength, Shore scleroscope hardness, and axial point load strength.
-
a study of rock abrasivity and tool wear in Coal measures rocks
International Journal of Coal Geology, 2008Co-Authors: Olgay Yarali, E Yasar, Gürkan Bacak, Pathegama Gamage RanjithAbstract:This paper examines the relations between Cerchar abrasivity index (CAI) and petrographic properties of Coal Measures Rocks in the Zonguldak Coal Basin, Turkey. In this study, petrographic properties and abrasivity indices of 29 sedimentary rock samples were determined and the values of CAI and petrographic analysis results were compared. A good linear relationship between CAI and average quartz grain size parameters was found. The test results also showed that abrasivity was affected by the mineralogical composition, cement type, degree of cementation, quartz content, and average quartz grain size. It was found that abrasivity of rock was decreased by the low grade of cementation between abrasive minerals. CAI values and petrographic properties were used to estimate tool consumption in underground works in the Zonguldak Coal Basin. It was observed that when CAI values increased, tool consumption increased.