O Membro Caldeirão (Formação Santa Brígida), Permiano, localizado na região nordeste do Brasil (Bacia de Tucano Central), é caracterizado pela acumulação de arenitos eólicos compreendendo duas associações de fácies: (i) dunas eólicas, e (ii) interdunas. A associação de fácies de dunas eólicas é caracteriza pela sobreposição de sets cruzados de dunas compostos basicamente por estratos de fluxos de grãos nas porções mais íngremes dos foresets que se interdigitam a base com estratos transladantes cavalgantes de marcas onduladas eólicas. As medidas de paleocorrentes dos estratos cruzados apresentam um sentido de mergulho médio para ENE. A associação de fácies de interdunas ocorre intercalada com estratos de dunas eólicas e possuem variação de fácies de alta frequência na sua deposição entre depósitos de interdunas secas, úmidas e encharcadas. As laminações cruzadas de marcas onduladas subaquosas apresentam paleocorrente para NNW indicando que as correntes fluviais encontravam-se confinadas nos corredores de interdunas. Os depósitos de interdunas ocorrem em posições específicas na sucessão estratigráfica e sugerem variações na taxa de subida do lençol freático e/ou na taxa de disponibilidade de areia seca durante a acumulação eólica. Quatro intervalos deposicionais foram encontrados para o Membro Caldeirão, numerados de I a IV, da base para o topo. Os intervalos I e III são caracterizados por sistemas eólicos secos, e os intervalos II e IV por sistemas eólicos úmidos. A alternância entre sistemas eólicos secos e úmidos podem estar relacionados com flutuações climáticas influenciadas por ciclos orbitais. / The Permian Caldeirão Member (Santa Brígida Formation), located in the northeast region of the Brazil (Tucano Central Basin), is characterized by accumulation of aeolian sandstones comprising two facies associations: (i) aeolian dune and (ii) interdune deposits. The aeolian dunes facies association is made up by trough to tangencial cross-bedding formed by grainflow strata on the steepest portions of the foresets that intertongue downwards with wind ripple translatent laminae. The aeolian cross strata shows a mean dip towards the ENE. The interdune facies association occur interlayered with aeolian dune cross-bedded sets and are compounded by facies indicative of dry, damp and wet depositional context suggesting high frequency variation in the humid of the interdune surface. The measured paleocurrents to NNW of the ripple cross-lamination indicate that streamflows was perpendicular to the migration direction of the cross-strata of aeolian dunes, confined to the interdune depressions. Interdunes deposits occur at specific intervals in the stratigraphic succession, suggesting temporal changes in the rate of the water table rise and/or of the dry sand availability. Four depositional intervals can be observed in aeolian succession of the Caldeirão Member, numbered I to IV, from bottom to top. Intervals I and III can be classified as dry aeolian systems, while intervals II and IV represent wet aeolian systems. The temporal alternation between dry and wet aeolian systems may be related to climatic fluctuations influenced by orbital cycles.

Orientador: Rodrigo de Souza Portugal / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-17T11:39:01Z (GMT). No. of bitstreams: 1 Sanchetta_AlexandreCruz_M.pdf: 1944469 bytes, checksum: 4ef771f7cb51787e86e285c870e84c53 (MD5) Previous issue date: 2010 / Resumo: O uso método de análise multivariada ICA (Análise de Componentes Independentes), mais o método K-NN (K-vizinhos mais Próximos) aplicados em dados de poços e em dados sísmicos buscando classificar fácies geológicas e suas características. Esses dois métodos foram aplicados em dados retirados do Campo de Namorado, na Bacia de Campos, Brasil. A ICA encontra as componentes independentes dos dados, que quando treinadas pelo método K-NN para reconhecer padrões nos dados, predizem fácies geológicas e outras informações sobre as rochas, como as características de reservatório. Essas componentes independentes configuram uma nova opção de interpretação das informações disponíveis, pois nessas novas variáveis, o espaço de análise não apresenta dimensões dependentes e exclui informações repetidas ou dúbias da interpretação dos resultados. Além disso, a maior parte da informação é resumida em poucas dimensões, resultando em uma possível redução de variáveis referentes ao problema. Um abundante número de testes foi feito procurando a taxa de sucesso desse método. Como taxa de sucesso, é compreendida a divisão do número de predições corretas dividido pelo número total de tentativas. O que se observa é uma taxa de sucesso alta, em torno de 85% de acerto em algumas situações, ressaltando-se que as componentes têm distribuição gaussiana, sendo que o método funciona melhor em encontrar componentes não-gaussianas. Mesmo nessa situação adversa o método se mostrou robusto. A solidez do método mostra-se uma alternativa para novas formas de interpretação geológicas e petrofísicas. Um dos trunfos desse método é que a base da sua aplicação pode ser estendida para outros tipos de dados, inclusive de naturezas físicas diferentes / Abstract: The use of multivariate analysis method ICA (Independent Component Analysis), plus the K-NN method (K-nearest Neighbor) applied on well log data and seismic data to predict the classification of geological facies and their characteristics. These two methods were applied to data from the Campo de Namorado, in the Campos Basin, Brasil. The ICA finds the independent components of the data that can be trained by K-NN method to recognize patterns in the data and predict the geological facies or other information about the rocks, as the characteristics of the reservoir. These independent components make up a new option for interpretation of available information, because with these new variables, the space has no dependent dimensions and the duplicate information or dubious interpretation of results are excluded. Moreover, most of the information is summarized in a few dimensions, resulting in a possible reduction of variables related to the problem. An abundant number of tests were done looking for the success rate of this method. As success rate, it is understood by the division of the number of correct predictions divided by total attempts. What is observed is a high success rate, around 85% accuracy in some situations, pointing out that the components have a Gaussian distribution and the method works best in finding non-Gaussian components. Even in this adverse situation the method was robust. The robustness of the method proves that ICA can be an alternative to new forms of geological and petrophysical interpretation. One of the advantages of this method is that the basis of their application can be extended to other types of data, including datas with different physical natures / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Orientador: Giorgio Basilici / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-13T23:50:03Z (GMT). No. of bitstreams: 1 Henrique_Andre_M.pdf: 11951186 bytes, checksum: 6061e17e64f904f61a28dc56429cad0c (MD5) Previous issue date: 2009 / Resumo: A Formação Punta Negra (Meso- Neodevoniano da Pré-Cordilheira Argentina) consiste em uma espessa sucessão de depósitos siliciclásticos de água profunda. Esta unidade aflora por cerca de 300 km em direção N-S nas províncias de San Juan, Mendoza e La Rioja. Uma detalhada análise sedimentológica permitiu identificar seis litofácies depositadas pela ação de fluxos de densidade concentrados e correntes de turbidez. Três associações de fácies foram descritas e interpretadas: i) preenchimento de canais: camadas de arenito fino, com escassas estruturas e preenchendo feições erosivas, correspondentes a canais pouco espessos como sistema de aporte em uma rampa proximal; ii) lobos proximais: sucessões estrato-crescentes de camadas arenosas maciças na base e com estruturas de tração no topo, amalgamadas ou interacamadadas com níveis de lamito laminado, correspondendo a deposição de lobos num contexto de rampa proximal; iii) lobos distais/franjas: sucessões de lamito e camadas descontinuas de arenito muito fino que constituem os depósitos mais finos de todo o intervalo estudado, associados ao contexto de rampa distal. Os corpos sedimentares pertencentes às associações de fácies constituem elementos com características geométricas próprias. Os canais são do tipo deposicionais e pouco erosivos, os lobos deposicionais caracterizam corpos de geometria lobada/linguoide apresentando ciclos de compensação de espessuras. Por fim, os depósitos de franjas possuem grande extensão areal e com heterogeneidade acentuada pelo interacamadamento lamito/arenito. Com base na análise de fácies e associação de fácies e em informações levantadas por estudos anteriores, propõe-se um modelo de sistema deposicional turbidítico de rampa submarina rico em areia, caracterizado por um sistema de canais pouco espessos que atuam na forma de múltiplos pontos de aporte. A característica textural imatura dos sedimentos, a abundância de fragmentos vegetais e a deposição de estruturas típicas de fluxos de mais longa duração, são argumentos para propor um sistema de alimentação por meio de fluxos hiperpicnais provenientes diretamente do continente / Abstract: The Punta Negra Formation (Middle to Late Devonian of Argentine Precordillera) is a thick succession of siliciclatic deep-water deposits. This unit outcrops for c. 300 km along north-south direction in the provinces of San Juan, Mendoza and La Rioja. Detailed sedimentological permitted to identify six lithofacies deposited by concentrated density flows and turbidity currents. Three facies associations were described and interpreted: i) channel-filling deposits: massive fine grained sandstone erosive depressions that represent multiple shallow channels in a ramp system; ii) proximal lobes: thickening-upward successions of fine grained massive sandstone beds with a upper portion of very fine laminated sandstone; these beds are amalgamated or interbedded with laminated mudstone and represent depositional lobes in a proximal ramp context; iii) distal lobes/fringe: interstratifications of mudstone and very fine sandstone that are associated to a distal ramp. The channels are constituted of multiple depositional and minor erosional events. The depositional lobes include linguoid bodies with compensation cycles. The fringes have large extension and are characterized by thin interbedding of mudstone/discontinuous very fine sandstone. It was proposed a sand-rich deep-water ramp depositional model, which is characterized by a system of multiple minor erosive channels (multiple source). The immature sediments, the abundance of vegetal fragments and the typical structures of relative long-lived flows evidence a depositional system fed by hyperpicnal flows probably originated of major fluvial floods / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Orientador: Giorgio Basilici / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-14T04:13:31Z (GMT). No. of bitstreams: 1 MorettiJunior_PauloAugusto_M.pdf: 5701785 bytes, checksum: d478ca8c79173f62ad9807c930cc0332 (MD5) Previous issue date: 2009 / Resumo: Esta dissertação consiste no estudo sedimentológico e paleodeposicional de quatro unidades litoestratigráficas da Pré-Cordilheira Argentina, depositadas durante o Ordoviciano: Formação Portezuelo del Tontal (FPT), Formação Sierra de La Invernada (FSI), Formação Gualcamayo (FG) e Formação Los Azules (FLA). A FG e a FLA são caracterizadas por lamitos e margas depositados por decantação. A FPT é constituída por uma alternância entre arenitos finos a muito finos e lamitos. Os arenitos são frequentemente bipartidos: a porção basal, de granulometria areia média a fina, é espessa e maciça, apresentando intraclastos lamosos, tapetes de tração. A porção superior possui granulometria mais fina e é menos espessa, com laminação cruzada truncante anisotrópica (anysotropic hummocky cross stratification). Os arenitos são interpretados como gerados por fluxos gravitacionais influenciados por tempestades. A presença de laminação cruzada truncante na parte superior das camadas demonstram que a sedimentação ocorreu acima do nível de ondas de tempestades e que um fluxo gravitacional se desenvolveu concomitantemente às tempestades. A FSI é caracterizada por arenitos muito finos com laminação truncante anisotrópica intercalada com lamitos arenosos produzidos por correntes de turbidez muito diluídas e por decantação. A FSI apresenta abundantes icnofósseis, o que indica uma atividade biológica bentônica ativa. O sistema deposicional da FPT e da FSI é uma plataforma dominada por atividade de tempestades. A parte superior da FSI e a FPT são litologicamente semelhantes e ambas apresentam direções de paleocorrentes de norte para sul, o que evidencia que eram parte de uma mesma bacia. Os arenitos mais grossos e espessos, representados pelos depósitos da FPT, teriam passado por ambientes mais rasos (FSI) e se depositado em áreas mais profundas (FPT). Os depósitos arenosos muito finos gerados por tempestades são característicos de áreas mais rasas e proximais (FSI). A margem ocidental do Gondwana, durante o Meso e Neo-Ordoviciano, foi uma plataforma siliciclástica dominada por tempestades, com aprofundamento para sul localizada em uma bacia do tipo antepaís. / Abstract: This work consists in the study of sedimentological and paleodepositional features of four Ordovician lithostratigraphic units of the Precordillera Argentina: Portezuelo del Tontal Formation (PTF), Sierra de La Invernada Formation (SIF), Gualcamayo Formation (GF) and Los Azules Formation (LAF). The PTF is represented by alternating fine- to very fine grained sandstone and shale. Most sandstone strata are bipartite: a thicker lower part, medium to mediumfine grained size, massive, showing buoyant muddy clasts or traction carpet, and a thinner upper part, very fine in grain size, with anisotropic hummocky cross-stratifications. The sandstone is interpreted as gravitational flow generated by and combined with storms. The presence of anisotropic hummocky cross-stratification in the upper part of the strata testifies that the sedimentation occurred above the storm wave base and that the gravitational flow developed contemporaneously to the storm activity. The SIF is characterized by very fine-grained sandstone showing anisotropic hummocky cross stratifications, alternated with sandy pelite showing thin sandstone beds produced by low-density turbidity currents. The SIF is rich in ichnofossils, testifying a high biological benthic activity. The LAF and GF are characterized by shale and marl facies deposited mainly by settling. The depositional system of the PTF and SIF is dominated by storm activity. The transition of the upper part of the SIF to lithologies similar to PTF and analogous paleocurrent directions, from north to south, suggests that both formations take part of the same depositional basin. The thicker and coarser sandstones, represented by the PTF deposits, bypassed shallower areas (SIF) and deposited in deeper areas (FPT). Very fine storm generated sandy deposits in SIF were characterized by shallower and proximal areas. The western margin of the Gondwana in the middle-late Ordovician was characterized by storm-dominated siliciclastic shelf deposits in a foreland basin. The margin showed a progressive deepening toward south. / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

M.Sc. / This work documents the lithostratigraphy and interpreted depositional environments of the Permian Vryheid Formation in the most northern proximal setting yet studied in the Witbank Coalfield. Data from 924 boreholes from two mining companies (Anglo Operations Ltd. and Xstrata Coal Ltd.) drilled over 50 years, covering an area of 910km2 revealed a 35m sequence of terrigenous clastic sedimentary rocks containing two coal seams. These seams are numbered No. 1 at the base and No. 2 at the top. Delineation of facies type, facies assemblages, lateral facies distributions and computer-based three-dimensional modeling facilitated the interpretation of the palaeodepositional environments. Eleven lithofacies are defined and interpreted hydrodynamically. Facies classification is based primarily on grain size and sedimentary structures. The modeling of the borehole information uses the finite element method to interpolate the thickness, roof and floor surfaces and trend of each seam and inter-seam parting between boreholes. The spatial position of the boreholes is defined using a digital terrain model that represents the current surface topography. Lateral distributions were correlated by repositioning the boreholes using the base of the No. 2 seam as a datum. Glaciofluvial, glaciolacustrine, bed-load (braided) fluvial and constructive progradational deltaic environments are interpreted in the study area. Fluvial channel sequences are dominant and cause the thinning of the coal seams below channel axes as well as splitting of both the No. 1 and No. 2 seams. Glaciofluvial influences also affect the lower portion of the No. 1 seam. Basement palaeotopography restricts the distribution of the lower splits of the No. 1 seam. The coals either ‘pinch-out’ or are absent above basement highs but blanket the adjacent low-lying areas. In contrast to the greater Witbank Coalfield, but concurrent with other studies in the more northern proximal regions, fluvial systems dominate over deltaic systems in the study area. Glaciodeltaic, fluviodeltaic and anastomosed channel fluvial systems recognized in the remainder of the Karoo Basin were fed by the braided fluvial systems in the study area. The close proximity of the study area to the northern edge of the basin accounts for the subtle differences in lithostratigraphy and interpreted depositional environments when compared with more distal sites to the south. For example, glaciofluvial clastic sediment input in the lower portions of the No. 1 seam and post-Karoo erosion that has removed the overlying seams; the deltaic progradational sequence, above the No. 2 seam, occurs twice in succession and the bioturbation, that has become characteristic of sedimentary sequence of the Vryheid Formation above the No. 2 seam in the central and southern parts of the Karoo Basin, is not as identifiable. These differences are explained by the extreme proximal location of the study area on the northern basin margin relative to the remainder of the Karoo Basin.

M.Sc. / The coal-bearing Permian Vryheid Formation of the Ecca Group (Karoo Supergroup) was investigated at New Denmark Colliery, situated in the north east section of the Karoo Basin, South Africa. The lithostratigraphy of the sequence is defined in terms of conventional lithostratigraphic terminology but also by applying detailed genetic stratigraphic schemes that have previously been proposed for the adjacent coalfields. The succession is divided up into depositional sequences named after the underlying and overlying coal seams, the No. 2, 3, 4 and 5 seam sequences. The sedimentary succession was divided up into five facies, namely: conglomerate facies, sandstone facies, interlaminated sandstone-siltstone facies, siltstone facies and coal facies. These were interpreted hydrodynamically. Facies assemblages were then interpreted palaeoenvironmentally. Glacial, fluvial, deltaic and transgressive marine sequences were responsible for forming this sedimentary succession. Attention was then focussed on the main economic No. 4 seam, which is mined underground at the colliery. Detailed subsurface geological cross-sections, core sequences and isopach maps of the No. 4 seam coal and the lithologies above, were used to determine specific aspects of the depositional environment that could contribute to unstable roof conditions above No. 4 seam. Coarsening-upward deltaic cycles, fining-upward bedload fluvial cycles, glauconite sandstone marine transgressions and crevasse-splay deposits are recognized in the overlying strata. Poor roof conditions occur parallel to palaeochannel margins because the interbedded channel sandstone and adjacent flood plain argillites cause collapsing along bedding plane surfaces. Rider coals overlying thin crevasse-splay sequences in close proximity to the No. 4 seam, create one of the most serious roof conditions; complete collapse occurs along the rider coal contact with the underlying splay deposits. Differential compaction of mudrock/shale/siltstone over more competent sandstone causes slickensided surfaces that weaken the roof lithologies. Correct identification of these sedimentological features will enable the prediction of potential poor roof conditions during mining operations and mine planning.

Philosophiae Doctor - PhD / Sandstone and shale samples were selected within the systems tracts for laboratory analyses. The sidewall and core samples were subjected to petrographic thin section analysis, mineralogical analyses which include x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and stable carbon and oxygen isotopes geochemistry to determine the diagenetic alteration at deposition and post deposition in the basin. The shale samples were subjected to Rock-Eval pyrolysis and accelerated solvent extraction (ASE) prior to gas chromatographic (GC) and gas chromatographic-mass spectrometric (GC-MS) analyses of the rock extracts, in order to determine the provenance, type and thermal maturity of organic matter present in sediments of the Orange Basin. The results revealed a complex diagenetic history of sandstones in this basin, which includes compaction, cementation/micritization, dissolution, silicification/overgrowth of quartz, and fracturing. The Eh-pH shows that the cements in the area of the basin under investigation were precipitated under weak acidic and slightly alkaline conditions. The δ18O isotope values range from -1.648 to 10.054 %, -1.574 to 13.134 %, and -2.644 to 16.180 % in the LST, TST, and HST, respectively. While δ13C isotope values range from -25.667 to -12.44 %, -27.862 to -6.954% and -27.407 to -19.935 % in the LST, TST, and HST, respectively. The plot of δ18O versus δ13C shows that the sediments were deposited in shallow marine temperate conditions. / South Africa

>Magister Scientiae - MSc / This study has been conducted to accurately determine fluid saturation within Fula sub-basin reservoirs which is located at the Southern part of the Republic of Sudan. The area is regarded as Shaly Sand Reservoirs. Four deferent shaly sand lithofacies (A, B, C, D) have been identified. Using method based on the Artificial Neural Networks (ANN), the core surrounding facies, within Fula reservoirs were identified. An average shale volume of 0.126 within the studied reservoirs was determined using gamma ray and resistivity logs. While average porosity of 26.7% within the reservoirs was determined using density log and the average core grain density. An average water resistivity of 0.8 Ohm-m was estimated using Pickett plot method. While formation temperature was estimated using the gradient that constrained between surface and bottom hole temperature. Water saturation was determined using Archie model and four shaly sand empirical models, the calculation was constrained within each facies zone to specify a model for each facies, and another approach was used to obtain the water saturation based on Artificial Neural Networks. The net pay was identified for each reservoir by applying cut-offs on permeability 5 mD, porosity 16%, shale volume 0.33, and water saturation 0.65. The gross thickness of the reservoirs ranges from 7.62m to 19.85m and net pay intervals from 4.877m to 19.202m. The study succeeded in establishing water saturation model for the Fula sub-basin based on neural networking which was very consistent with the core data, and hence has been used for net pay determination.

Orientador: Giorgio Basilici / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-31T21:55:14Z (GMT). No. of bitstreams: 1 Cesar_PauloHenriqueTavares_M.pdf: 3736356 bytes, checksum: 3d8dd5ffaf2d7b3591926eadf6fdeb18 (MD5) Previous issue date: 2001 / Resumo: O presente trabalho é uma análise vertical de depósitos marinhos profundos, cujos processos deposicionais se dá por fluxos gravitaticionais, na Unidade Apiúna, na Bacia do Itajaí, Estado de Santa Catarina. Os dados estão dispostos em 5 seções, das quais as 4 primeiras são correlacionáveis, com aproximadamente 200 metros de espessura total, 524 camadas e 102 transições de fácies. Em que a média das camadas é de 25 cm. Através da transformada de Fourier, no domínio da freqüência obteve-se os seguintes dados: nenhum ciclo na seção 1; 2 ciclos na seção 2; 11 ciclos na seção 3; 6 ciclos na seção 4; 4 ciclos na seção 5 e 16 ciclos nas seções 1-4, que puderam ser correlacionáveis. As freqüências (ciclos), foram definidas com o auxílio da análise visual da seções. Com relação aos ciclos de afinamento ou engrossamento ascendente (megassequências), os resultados foram: engrossamento ascendente: 2 na seção 2, 6 na seção 3, 2 na seção 4 e 18 na seçôes 1-4, enquanto que o afinamento ascendente:3 na seção 3,3 na seção 4,3 na seção 5 e 10 nas seções 1-4. Existe diferença entre a análise visual e a função da freqüência, porém as megassequências, foram definidas segundo a análise visual. A análise de Markov corrobora que as principais transições estão inseridas num contexto de lençóis de areia, proximais e distais, em que ocorre a intercalação de arenitos fino a médio, intercalados com finas camadas de arenito com siltito, respectivamente fácies D e E. Diante de tais observações foi possível refutar a inclusão da Unidade Apiúna, num clássico depósito de leques profundos supridos por canyon, pois como largamente disposto na literatura, este depósitos apresentam seqüências de engrossamento ou afinamento ascendente (thinning e thickening upward), o que se expressa nas 5 seções de maneira bastante tímida. Quanto aos trends de granulometria, que pode refletir que o mecanismo de deposição, o fluxo de detritos (debris flow) é dominante, em detrimento de correntes de turbidez (turbidite currents), isto porque não é comum a gradação ascendente nas camadas de arenito, sendo somente no topo de algumas camadas que ocorrem este último fenômeno. Foi possível diferenciar quatro associações de fácies, numeradas de 1 a 4 a seguir: depósitos de slope, depósitos de lençóis de areia proximais, depósitos de lençóis de areia distais e finalmente depósitos de canal-dique marginal / Abstract: This work is a vertical analysis of deepwater deposits outcrops, whose depositional processes occurs by gravity flows in the Apiúna Unit, Itajaí Basin, Santa Catarina State. The data are organized in 5 sections where each section is one outcrop. The sections from 1 to 4 have mutual correlation, with almost 200 m of total thickness, 534 beds and 102 facies transitions. Through Fourier transform, in the frequency domain, 16 sequences was obtained, defined by visual analysis of thickness beds. The results for the sequences of thinning and thickening upward were: 10 of thickening upward and 6 of thinning upward. The vertical trends of fining upward are often randomic. The use of Markov Chain's tooI confirmed the main facies transitions which are located in a context of sheet sands, proximal and distal, in which occurs the superposition of fine to medium (D facies) sandstones with the thin beds of sandstone and siltstone (E facies ). According to the data above, it was possible to refuse the Apiuna Unit as a classical canyon-fed deposits of deep water fan, because of absence of better defined and low abundant sequences of thinning and thickening upward. The debris flow is the main depositional processes, while turbidity currents occur in the upper part of flow in some sandstone beds. This configuration is showed in the beds with the trend of fining upward. It was possible to identify four facies associations, namely: slope deposits; proximal sheet sands; distal sheet sands and channel-levee / Mestrado / Mestre em Ciências e Engenharia de Petróleo

>Magister Scientiae - MSc / This study is aimed at illustrating the reservoir heterogeneity in the BCII - BCI interval of the Ga-field, offshore South Africa. This was achieved by generating a conceptual static model as a predictive tool for the BCII - BCI interval. The reservoir zones between BCII - BCI were sub divided into two major zones, viz: zone A and zone B. Petrophysical analysis was conducted on the three wells Ga-A3, Ga-Q1 and Ga-Q2. The application of the sequential gaussian algorithm ensured that all of the available data was honoured to the highest extent in generating the realisations to display the heterogeneity of the BCII – BCI sandstone reservoir. Sampling values from the well logs were extrapolated into the 3D grid. Each reservoir contained a percentage of shale or clay of about 45% -50%. Small scaled reservoir heterogeneity has been construed to the influence of the sedimentary structures. Large scaled reservoir heterogeneity has been identified, due to the lateral extent of the claystones which is widely distributed throughout the study area