A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2016 / The Mesoproterozoic Pilanesberg Complex, South Africa, is the world’s largest alkaline intrusive complex. Mapped geological field relationships suggest the Complex has circular inward dipping layers. However, it is unclear how the dipping layers extend at depth. As a result, the 3D geometry of the Pilanesberg Complex is unknown. Modelling of the Pilanesberg Complex uses 2D forward models as well as 3D forward and inversion, gravity and magnetic data models, to set limits on the 3D geometry of the Pilanesberg Complex. The 2D Bouguer gravity models and geology maps indicate that some of the Bushveld Complex Main Zone shifted to the west of the Pilanesberg Complex during emplacement. This, and a highly faulted country rock, accounts for a portion of how the host rock was able to accommodate the Pilanesberg Complex intrusion. The geometry of the Complex is explored with test gravity models where the model of outward dipping and vertically dipping cylinders are unable to match the Bouguer gravity signal over the Complex, but the inward dipping model matched the data to provide a possible solution for the geometry of the Complex. The Pilanesberg Complex geometry is modelled with 3D magnetic inversion, 3D forward gravity models and 2.5D gravity test profiles that were all constrained by the surface geology. The different models correlate so that best data fit for the Complex is represented by an overall inward dipping structure. Surface geological measurements indicate that the northern edge of the Complex dip out to the north. The 3D forward modelling was able to produce a positive solution that matched the gravity data with a northward dipping northern edge. The dipping northern edge is also observed on the University of British Columbia, UBC, 3D gravity inversion and the Euler deconvolution gravity profile solutions. The depth of the Pilanesberg Complex from 3D forward gravity modelling is estimated to be between 5 and 6 km. The Complex is suggested to have undergone block movement where the northern block and southern block are separated by the 30 km long Vlakfontein fault, which bisects the Complex from the north-east to the south-west. The image processing contact depth, Euler deconvolution solutions and the 3D Voxi inversion model suggest that the fresh bedrock is closer to surface in the north, while the southern block appears to be approximately 1km deeper than the northern block. The northern dip and block movement are explained by complicated structural events that include trap door graben settling which hinged on the northern edge as well as faulting and external block movement during a regional lateral extensional event. The Pilanesberg Complex intruded during a larger system of alkaline intrusions, known as the Pilanesberg Alkaline Province. The intrusions are associated with the Province due to their ages and chemical affinity. This Province includes two dyke swarms that radiate to the north-west and south of the Pilanesberg Complex, as well as smaller circular clinopyroxenite intrusions throughout the Bushveld Complex. The Pilanesberg dyke system and the circular clinopyroxenite intrusions are reversely magnetised with IGRF corrected values ranging between -150 to -320 nT compared to the normally magnetised 166 to 330 nT values of the Pilanesberg Complex. This suggests that a magnetic reversal occurred between the emplacement of the Pilanesberg Complex and the dyke System. The age data of the Complex and dyke Swarm suggest a magnetic reversal could have occurred between the emplacement of the Pilanesberg Complex and the Pilanesberg dyke System. The Complex is dated at 1602 ± 38 Ma and 1583 ± 10 Ma, from two white foyaite samples from the southern edge (using 40Ar/39Ar amphibole spectrum analysis). These ages are vastly different from previously reported ages, which ranged between 1200 Ma and 1450 Ma (Harmer R., 1992; Hansen et al., 2006). The error analysis has improved considerably from the published dates making the proposed dates plausible for the intrusion of the Pilanesberg Complex as the first and main intrusion of the Pilanesberg Alkaline Province. The Pilanesberg dyke System intruded much later between 1219 ± 6 Ma to 1268 ± 10 Ma for the red syenite dyke samples (using 40Ar/39Ar on feldspars spectrum analysis) and 1139 ± 18 Ma obtained for the grey syenite dyke (using 40Ar/39Ar on amphiboles inverse isochronal analysis). The dyke Swarm dates are significantly younger than the previously published ages for the dykes, which were between 1290 Ma and 1330 Ma (Van Niekerk, 1962; Emerman, 1991). / LG2017

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy University of the Witwatersrand School of Geosciences and Dublin Institute for Advanced Studies School of Cosmic Physics Geophysics Section February 2016 / Archean cratons, and the Proterozoic orogenic belts on their flanks, form an integral part of the Southern Africa tectonic landscape. Of these, virtually nothing is known of the position and thickness of the southern boundary of the composite Congo craton and the Neoproterozoic Pan African orogenic belt due to thick sedimentary cover. In this work I present the first lithospheric-scale geophysical study of that cryptic boundary and define its geometry at depth. The results are derived from two-dimensional (2D) and three-dimensional (3D) inversion of magnetotelluric data acquired along four semi-parallel profiles crossing the Kalahari craton across the Damara-Ghanzi-Chobe belts (DGC) and extending into the Congo craton. Two dimensional and three-dimensional electrical resistivity models show significant lateral variation in the crust and upper mantle across strike from the younger DGC orogen to the older adjacent cratons. The Damara belt lithosphere is found to be more conductive and significantly thinner than that of the adjacent Congo craton. The Congo craton is characterized by very thick (to depths of 250 km) and resistive (i.e. cold) lithosphere. Resistive upper crustal features are interpreted as caused by igneous intrusions emplaced during Pan-African magmatism. Graphite-bearing calcite marbles and sulfides are widespread in the Damara belt and account for the high crustal conductivity in the Central Zone. The resistivity models provide new constraints on the southern extent of the greater Congo craton, and suggest that the current boundary drawn on geological maps needs revision and that the craton should be extended further south. The storage possibilities for the Karoo Basins were found to be poor because of the very low porosity and permeability of the sandstones, the presence of extensive dolerite sills and dykes. The obvious limitation of the above study is the large spacings between the MT stations (> 10km). This is particularly more limiting in resolving the horizontal layers in the Karoo basin. However the 1D models provide layered Earth models that are consistent with the known geology. The resistivity values from the 1D models allowed porosity of the Ecca and Beaufort group lithologies to be calculated. It is inferred that the porosities values are in the range 5-15 % in the region below the profile. This value is considered too low for CO2 storage as the average porosity of rock used for CO2 is generally more than 10 to 12 percent of the total rock unit volume.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2015 / Three new methods for determining the structural index and source distance for magnetic field data are presented. These methods require only the calculation of the first and second order analytic signal amplitudes of the total field and are applicable to both profile and gridded data. The three methods are first tested on synthetic data and then on two real datasets to test for applicability and repeatability. It was found that each method had different strengths and weaknesses and thus one method cannot be favoured over the others. Cooper (2014) describes how to calculate the distance to source over both profile and gridded data given a user defined structural index. Often however, particularly in the case of real data, the structural index is not known or varies over the surveyed area. These three new methods however do not require any user input since the structural index is calculated thus making them more applicable to regions of unknown geology. It was found that the first of the three new methods, the multi-distance inversion method, was best used as an edge-detection filter, since the use of higher order derivatives resulted in increased noise levels in the distance to source calculation. The third of these new methods, the unconstrained inversion method, discussed in Chapter 7, not only solves for the structural index but also determines the depth of the source. In that particular case, the structural index is used as a rejection filter, whereby, depth solutions associated with structural index values outside of the expected range are deemed to be invalid. Unlike the third new method, the first two methods require the distance to source to be calculated via the approach described by Cooper (2014) (which requires the user to define the structural index), the results of which are later rescaled by the calculated structural index to yield what is termed a rescaled distance to source. All three of the new methods are fully automatic and require no user control. The techniques were first tested on both profile and gridded theoretical data over sources with known structural index values. All of the methods were able to estimate the structural index of each of the particular sources and give depth estimates that varied from the true depth by less than 20 percent (with deeper sources being more inaccurate). Noise was also added to the theoretical data in an attempt to assess how the methods can be expected to perform with real data. It was found that when applied to noisy data, these methods performed equally well to slightly worse, than when the method developed by Cooper (2014) was used. As a real world case study these three new methods were tested on aeromagnetic data collected over the Kuruman Military Area, Northern Cape, South Africa. Regional deformations as well as later intrusive dykes and cross cutting faults were imaged by the chosen depth determination procedures. The dolerite dykes in the area were found to occur between 20 to 60 m deep. While the sand cover was estimated to be between 30 to 40 m thick. Overall, the techniques yield distance to source estimates that differ by less than 15 m, over sources, to the results obtained by using the source distance method (Cooper, 2014). To test for repeatability a second aeromagnetic dataset, collected over a dyke swarm within the Bushveld Complex, South Africa was considered. Again comparable (less than 15 m over sources) depth estimates were made between the unconstrained and constrained inversions. Since the distance to source estimates produced by these new unconstrained inversion methods are comparable to those produced by constrained inversion (Cooper, 2014) the project can be deemed successful.

A demanda por fontes renováveis de energia juntamente com o esgotamento das reservas de combustíveis fósseis e do aquecimento global tem despertado grande interesse. A degradação da biomassa lignocelulósica para a produção de biocombustíveis tem se revelado uma alternativa viável, contudo tem enfrentado desafios em função de sua recalcitrância. Novos preparados enzimáticos envolvendo não só celulases com mecanismo hidrolítico, mas também proteínas com atividade auxiliares têm sido desenvolvidas e comercializadas. Contudo a adição de enzimas oxidativas nestes coquetéis ainda é passível de desenvolvimento e otimização. Nesse âmbito, o objetivo desse trabalho foi analisar três possíveis abordagens para a resolução desse problema. A primeira através do isolamento de fungos filamentosos de compostagem com o intuito de obter novas enzimas com função oxidativa. A segunda, constituiu o estudo de sinergismo de uma enzima acessória da família GH43 com o coquetel enzimático industrial Accellerase e a terceira no estudo da enzima oxidativa monooxigenases lítica de polissacarídeo (Lpmo) assim como sua interação sinérgica com uma endoglucanase de Trichoderma harzianum. A atividade celulolítica dos fungos foi determinada por análise do halo hidrolítico, assim como por reações enzimáticas utilizando substratos específicos. Os potenciais fungos produtores de enzimas oxidativas foram identificados por amplificação e sequenciamento da região ITS3. Dezesseis fungos foram isolados e testados, destes três apresentaram atividade positiva para a enzima lacase. O sequenciamento revelou que todos os fungos pertencem à mesma espécie patogênica Scedosporium prolificans, A enzima BlAbn1 (GH43) foi expressa em células de E. coli (BL21) e purificada para análise do sinergismo com o coquetel enzimático Accellerase em diferentes condições como sinergismo sequencial ou simultâneo, diferentes pH´s, tempo de reação e concentração enzimática. No sinergismo simultâneo e análises em pH 5 e pH 8 a taxa de sinergismo encontrada foi muito baixa apenas 4 %. Contudo no sinergismo sequencial com diferentes tempos e concentrações enzimáticas foi encontrado um aumento de 30 % na liberação de açúcares redutores na reação de 20 horas, mostrando que há ação sinérgica. O estudo da enzima oxidativa Lpmo foi realizado utilizando a enzima purificada após expressão heteróloga em Aspergillus nidulans. Análises com diferentes substratos e doadores de elétrons assim como sinergismo com uma endoglucanases foram realizados. Ácido ascórbico e pirogalol apresentaram-se como doadores de elétrons utilizando celulose amorfa (PASC), xilano e arabinoxilano como substratos. Ação sinérgica entre a endoglucanase e Lpmo foi observada, apresentando um aumento na liberação de açúcares redutores na ordem de 15 %. Em habitats naturais os microrganismos produtores de enzimas hidrolíticas e auxiliares apresentam ação sinérgica como demonstrado para enzimas da família GH43 com coquetéis enzimáticos e de enzimas oxidativas com endoglucanases. Este efeito pode ser explorado e utilizado na melhora da composição dos coquetéis enzimáticos dedicados á produção de biocombustíveis lignocelulósicos. / The demand for renewable energy sources coupled with the depletion of fossil fuel reserves and global warming has aroused great interest. The degradation of lignocellulosic biomass for the production of biofuels has proved to be a viable alternative, however it has faced challenges due to its recalcitrance. New enzymatic preparations involving not only cellulases with a hydrolytic mechanism, but also proteins with an auxiliary activity have been developed and commercialized. However the addition of oxidative enzymes in these cocktails is still amenable to development and optimization. In this context, the objective of this work was to analyze three possible approaches to solve this problem. The first one through the isolation of filamentous fungi from composting in order to obtain new enzymes with oxidative function. The second was the synergism study of an accessory enzyme of the GH43 family with the industrial enzymatic cocktail Accellerase and the third in the study of lytic polysaccharide monooxygenases (Lpmo) oxidative enzyme as well as its synergistic interaction with a Trichoderma harzianum endoglucanase. The cellulolytic activity of the fungi was determined by analysis of the hydrolytic halo, as well as by enzymatic reactions using specific substrates. Potential fungi producing oxidative enzymes were identified by amplification and sequencing of the ITS3 region. Sixteen fungi were isolated and tested, of these three showed positive activity for the lacase enzyme. Sequencing revealed that all fungi belong to the same pathogenic species Scedosporium prolificans. The enzyme BlAbn1 (GH43) was expressed in E. coli cells (BL21) and purified for synergism analysis with the enzymatic cocktail Accellerase under different conditions such as sequential synergism or Different pH, reaction time and enzymatic concentration. In simultaneous synergism and analyzes at pH 5 and pH 8 the synergism rate found was very low, only 4%. However in the sequential synergism with different times and enzymatic concentrations a 30% increase in the release of reducing sugars in the reaction of 20 hours was found, showing that there is synergistic action. The study of the oxidative enzyme Lpmo was performed using the enzyme purified after heterologous expression in Aspergillus nidulans. Analyzes with different substrates and electron donors as well as synergism with an endoglucanase were performed. Ascorbic acid and pyrogallol were presented as electron donors using amorphous cellulose (PASC), xylan and arabino-xylan as substrates. Synergistic action between endoglucanase and Lpmo was observed, with an increase in the release of reducing sugars approximately 15%. In natural habitats, the microorganisms producing hydrolytic and auxiliary enzymes present synergistic action as demonstrated for enzymes of the GH43 family with enzymatic cocktails and oxidative enzymes with endoglucanases. This effect can be exploited and used in improving the composition of the enzymatic cocktails dedicated to the production of lignocellulosic biofuels.

Nos últimos anos, estudos de prospecção geoquímica aliados à análise estatística e a técnicas de geoprocessamento tornaram-se imprescindíveis na busca por novos depósitos minerais. O Serviço Geológico do Brasil (CPRM) executou o levantamento geoquímico na porção leste do Estado do Rio Grande do Sul, em uma área de aproximadamente 32.481 km², e disponibilizou dados de sedimentos de corrente e de concentrado de bateia. A área desse estudo está situada sobre o Escudo Sul-rio-grandense, mais especificamente no Cinturão Dom Feliciano Leste. Trata-se de uma área formada por um volumoso magmatismo granítico com características de retrabalhamento crustal, na qual predominam rochas de idades proterozóicas. Apesar de pesquisas pontuais haverem encontrado indícios para a descoberta de novas ocorrências minerais na porção leste do escudo, esta tem sido pouco estudada. Sendo assim, este trabalho objetivou investigar possibilidades de novos alvos a partir da identificação de valores anômalos nesta região, empregando técnicas estatísticas e de geoprocessamento. Foram analisadas 1528 amostras de sedimentos de corrente e 1477, de concentrados de bateia, disponibilizadas no banco de dados digital da CPRM (Geobank) Determinaram-se os limiares para elementos químicos de sedimentos de corrente que possibilitaram identificar áreas anômalas. Os dados de concentrados de bateia foram tratados de forma distinta, a partir da construção de mapas de densidade do tipo Kernel. As áreas anômalas foram apresentadas de duas formas distintas. As Anomalias Puramente Estatísticas correspondem às regiões que apresentaram elementos químicos com valores acima do limiar e consideram apenas a posição geográfica destes, independentemente da afinidade existente entre os mesmos. Já as Anomalias Prospectivas foram assim denominadas, pois a delimitação da área anômala foi baseada no agrupamento de elementos que possuem afinidade, utilizando conceitos de prospecção como assinatura geoquímica e elementos farejadores. Os resultados encontrados apontam para seis áreas anômalas na porção leste do escudo sul-riograndense, os quais apresentam assinaturas de depósitos IOCG, Pórfiro-epitermal e depósitos relacionados a granitos estaníferos. Este estudo geoquímico de escala regional revelou áreas anômalas inéditas no escudo sul-riograndense. Fica claro que existe um alto potencial na área da metalogenia a ser ainda estudado. / In the last few years, geochemical prospective studies allied to statistical analysis and geoprocessing techniques became indispensable in the search for new mineral deposits. The Brazilian Geological Survey (CPRM) performed a geochemical survey in the eastern portion of the Rio Grande do Sul State, in an area that covers 32.481 km², and provided stream sediment and pan concentrate data. The studied area is situated in the Rio Grande do Sul’s Shield, more specifically in the Dom Feliciano Eastern belt. The area is constituted by a massive granitic magmatism with crustal reworking characteristics, in which rocks of Proterozoic age prevail. Although some researches had found clues of new mineral occurrences in the eastern part of the Shield, it is still understudied. Thus, this study aimed to investigate the possibilities of new targets from the identification of anomalous values in the region, employing statistical and geoprocessing techniques. 1528 stream sediment and 1477 pan concentrate samples are available in the digital database of CPRM (Geobank) were analysed. The threshold values for stream sediment chemical elements were determined, which allowed identifying the anomalous areas The pan concentrate data was analysed differently, from the construction of Kernel density maps. The resulting anomalous areas of this study were presented in two different ways, as Purely Statistical Anomalies (PSA) and Prospective Anomalies (PA). The regions that presented chemical elements above the threshold value, considering just their geographical position, regardless of the chemical affinity between the elements, were denominated Purely Statistical Anomalies. In the Prospective Anomalies, the delimitation of the anomalous area was based on the grouping of the elements that had chemical affinity, using prospective concepts as geochemical signature and pathfinder elements. The results pointed to six anomalous areas in the Sul-Riograndense Shield, which presented signatures of Iron oxide copper-gold (IOCG), porphyry-epithermal and stanniferous granites deposits. This regional scale geochemical study revealed unprecedented anomalous areas in the Sul-Riograndense Shield. Besides that, it became clear that there is a great metallogenic potential that still need to be studied.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Geophysics . / Rockbursts continue to be one of the more high profile and problematic worker hazards in the South African gold mining industry. Recent advances in the technology of seismic monitoring systems and seismic data analysis and interpretation methods hold considerable promise towards improving the success rate of rockburst control measures. This study tests different methods for the evaluation of the response of geological structures to mining induced stress changes. A small part of Western Holdings Gold Mine in the Welkom goldfield -- the Postma Area -- offers a challenge because of its geological complexity, accessibility and high incidence of seismicity. The sensitivity of the local network to ground motions in this area of interest and the expected spatial location accuracy is established and deemed adequate for a detailed investigation of seismic activity. The local mining geometry, geology and methods of mining are discussed. The fractured state of the rock mass observed in situ, close to the stope faces, is in agreement with the results of numerical elastic modelling and the high stresses inferred seismically. Almost immediately after the incidence of a large event (ML 3.7) which occurred close to one end of a dyke, an increased rate of seismic activity became apparent at another part of the same dyke, some 250 m to the east. A change in the state of seismic stress, before and after the large event, points to a transfer of stress along this geological discontinuity. A quantitative analysis of recorded seismicity indicates spatial and temporal variations in the state of stress and strain throughout the rock mass surrounding Mining excavations. The elastic stress modelling performed routinely by rock mechanics engineers in the deep gold mines is, by itself, incapable of catering for the rheological nature of the rock mass, but taken together with independent seismic evaluations of a fault orthogonal to a highly stressed dyke it is shown that both methods are mutually complementary and can enhance the assessment of the seismic instability of the structures. A back-analysis is conducted on ten large seismic events (ML 2.5) to identify precursors. These show that the timely recognition of high gradients in physical seismic parameters pertaining to strain rate and stress in time and space immediately prior to major seismic events is a real and practical possibility, as such constituting an early warning mechanism. The fore-warning of a large event is best served by an analysis of seismicity over the short term (weeks or days) through time-history variations and/or contouring of various seismic parameters, although long-term seismic responses (months or weeks) characterise specific patterns and trends which are useful in the forecast. / AC 2018

This is the first academic study of well costs and drilling times for Australia???s petroleum producing basins, both onshore and offshore. I analyse a substantial database of well times and costs sourced from government databases, industry and over 400 recent well completion reports. Three well phases are studied - Pre-Spud, Drilling and Completion. Relationships between well cost factors are considered, including phase time, phase cost, daily cost, rig day rate, well depth, basin, rig type, water depth, well direction, well objective (e.g. exploration), and type of completion (P&A or producer). Times and costs are analysed using scatter plots, frequency distributions, correlation and regression analyses. Drilling times are analysed for the period 1980 to 2004. Well time and variability in well time tend to increase exponentially with well depth. Technical Limits are defined for both onshore and offshore drilling times to indicate best performance. Well costs are analysed for the period 1996 to 2004. Well costs were relatively stable for this period. Long term increases in daily costs were offset to some extent by reductions in drilling times. Onshore regions studied include the Cooper/Eromanga, Surat/Bowen, Otway and Perth Basins. Offshore regions studied include the Carnarvon Basin shallow and deepwater, the Timor Sea and Victorian Basins. Correlations between regional well cost and well depth are usually high. Well costs are estimated based on well location, well depth, daily costs and type of completion. In 2003, the cost of exploration wells in Australia ranged from A$100,000 for shallow coal seam gas wells in the Surat/Bowen Basins to over A$50 million for the deepwater well Gnarlyknots-1 in the Great Australian Bight. Future well costs are expected to be substantially higher for some regions. This study proposes methods to index historical daily costs to future rig day rates as a means for estimating future well costs. Regional well cost models are particularly useful for the economic evaluation of CO2 storage sites which will require substantial numbers of petroleum-type wells.

The increased level of greenhouse gases due to human activity is the main factor for climate change. CO2 is the main constitute among these gases. Subsurface storage of CO2 in geological systems such as coal reservoirs is considered as one of the promising perspectives. Coal can be safely and effectively utilized to both store CO2 and recover CH4. By injecting CO2 into the coal beds, methane is released with CO2 adsorption in the coal matrix and this process is known as enhanced coal bed methane recovery (ECBM). Zonguldak Coal Basin is one of the Turkey&amp / #8217 / s important coal resources. Since the coal seams in Bartin-Amasra field are found relatively deeper parts of the basin comparing to other places, this basin was not studied detailed enough yet. Bartin-Amasra basin was found convenient for enhanced coalbed methane recovery. The lithologic information taken from the Turkish Hard Coal Enterprise (TTK) was examined and the depths of the coal seams and the locations of the wells were visualized to perform a reliable correlation between seams existed in the area. According to the correlations, 63 continuous coal layers were found. A statistical reserve estimation of each coal layer for methane was made by using Monte Carlo simulation method. Uncertainty is an important parameter in risk analysis, for this reason the results were determined at probabilities of P10, P50 and P90. Enhanced coalbed methane recovery was simulated with CMG-GEM module using Coal Layer #26 which has more initial gas in place. The effects of adsorption, cleat spacing, compressibility, density, permeability, permeability anisotropy, porosity and water saturation parameters were examined in enhanced coalbed methane recovery by the simulation runs. The initial methane in place found in all these coal layers both in free and adsorbed states were estimated using probabilistic calculations resulted in possible reserve (P10) of 72.97 billion scf, probable reserve (P50) of 47.74 billion scf and proven reserves (P90) of 30.46 billion scf. Since the Amasra coal reservoir is not saturated with water, almost 10% of the total gas in place was found to be in the cleats as free gas. Coal layer #26 has an area of 4099 acres, average thickness of 6.23 ft and depth of 545 m (Karadon formation). P50 reserve estimation was 6.47 billion scf in matrix and 0.645 billion scf in fracture. Although the decrease in cleat porosity was less when shrinkage and swelling effects included, the decrease in cleat permeability as a function of porosity diminished the methane production. Cumulative methane production was enhanced with the injection of carbon dioxide (ECBM) approximately 23% than that of CBM recovery. Although closing the wells to production because of CO2 breakthrough had a negative effect on methane production initially, there was no difference between ultimate methane productions whether the wells remained open or closed, but more carbon dioxide was sequestered when the production ceased at the wells. Injected carbon dioxide amount of 5192 tonnes/year in base case was only capable to sequester only 0.3% of the yearly carbon dioxide emission of Zonguldak &Ccedil / atalagzi Power Plant nearby. Considering the gas in place capacity of the coal layer #26 as 15% of the resource area-A, it can be said that the project aiming ECBM recovery rather than carbon dioxide sequestration would be successful. In spite of water saturated coal reservoirs where the water production is required initially, it can be possible to start immediately the injection of CO2 with methane production for a dry coal reservoir. Cleat permeability being one of the most crucial parameter in the coal reservoir affected the rate of methane production. The more free gas was found in higher porosity cleat systems. Although the cumulative methane production was increased when the cleat porosity rose, methane recovery percentages were remained almost constant. The lower the cleat spacing the higher the rate of transfer between fracture and matrix was observed. The rate of gas desorption from the coal matrix and subsequent diffusion to both butt and face cleats was higher than the rate of flow in the face cleats, then production was flow-limited, pressure-driven and was defined by Darcy&amp / #8217 / s Law. The cumulative CH4 production was higher when the coal was denser. The change in coal compressibility affected slightly the cleat porosity and therefore the cleat permeability due to the change in reservoir pressure. Langmuir volume is defined as maximum adsorption capacity. Kozlu formation (deeper than Karadon formation) having lower Langmuir volume resulted in higher ultimate recovery because of lower Langmuir pressure than that of Karadon formation. In base case (Karadon formation), although the higher Langmuir volume was used, less methane production was observed. Permeability anisotropy generated the CO2-CH4 front in elliptic shape.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. / Bibliography: leaves 109-115. Also available online.

Thesis (Doctoral)--Universität Karlsruhe, 2000. / Abstract in German. Includes bibliographical references (p. 107-111). Also available via the World Wide Web. Also available via the World Wide Web. http://www.ubka.uni-karlsruhe.de/cgi-bin/psview?document=2000/physik/1 http://www.ubka.uni-karlsruhe.de/cgi-bin/psview?document=/2000/physik/2