By examining halokinetics and channel evolution in a deep-water system, we investigate how submarine channel morphology is affected by changing seascape linked to diapirism. The study area is located in Mississippi Canyon, Gulf of Mexico (GOM), situated directly off the continental slope in a prominent salt dome region. Interactions of salt domes with submarine channels in the GOM are poorly documented. Utilizing 3D seismic data and seismic geomorphology techniques, a long-lived Plio-Pleistocene submarine channel system has been investigated to develop a relationship between variable phases of salt movement and plan-form morphology of preserved channels. We suggest that halokinetics acts as a driver for topographic-channel evolution in the study area. We show how submarine channel morphology can be directly controlled by halokinetics, where salt movement can act as a structural control on both location and morphology of meandering channel complexes. Channels are able to move towards an equilibrium state only when holokinetics decreases.

O presente trabalho tem como objetivo estabelecer um procedimento metodológico e prático de estudo estratigráfico utilizando dados sísmicos, para bacias rifte, enfocando em análise tectônica e estratigráfica e sismofácies, especificadamente para bacias do tipo rifte. Para isso, foram utilizados os depósitos sedimentares do Grupo Lagoa Feia, Offshore da Bacia Campos, margem continental sudeste brasileira. O Grupo Lagoa Feia é caracterizado por sedimentos siliciclásticos, carbonáticos e evaporíticos depositados durante a fase rifte e pós-rifte. Linhas sísmica 2D, perfis litológico de poços exploratórios e testemunhos serviram como base de dados para suporte a este trabalho. Utilizando os conceitos fundamentais da sismoestratigrafia, padrão de refletores e dados litológico de poços, foram identificadas três sismofácies associados a meio-grabens da fase rifte: Sismofácies 1 (depósito de falha de borda) – tem sua ocorrência encaixada na falha de borda em uma zona ampla e bem definida; Sismofácies 2 (depósito de sedimentos finos) – amplamente identificada e grada lateralmente para a sismofácies 3; Sismofácies 3 (depósito de grainstones e rudstones) – têm ocorrência restrita e de ocorrência errática, tanto em zonas altas da margem flexural, quanto nas zonas profundas próximas do depocentro dos meiográbens analisados. Estas sismofácies identificadas nas linhas sísmica da Bacia de Campos foram transpostas para linhas selecionadas da Bacia de Santos, mostrandose operacional na definição de potenciais reservatórios. Uma quarta sismofácies distinta e de ocorrência pontual foi identificada. Esta sismofácies é caracterizada por forte descontinuidade nos refletores e efeitos de redução de amplitude, sendo identificada como vent hidrotermal. Auxiliado por exemplos da literatura, foram identificadas dez vents hidrotermais caracterizadas como do tipo dome e eye e identificados também, os dutos e corpos intrusivos associados a esta estrutura. Com os conceitos da estratigrafia de sequências adaptados para bacias do tipo rifte, foi proposto um arcabouço crono-estratigráfico que compreendeu unidades representativas de eventos distintos, com suas superfícies limítrofes (superfícies estratigráficas) e por vezes, superfícies funcionais (sem controle estratigráfico preciso). O arcabouço tectono-estratigráfico da sucessão rifte foi subdividido em uma fase prérifte, sin-rifte e pós-rifte. O intervalo sin-rifte foi subdividido com base nos padrões geométricos dos refletores, visto que as sismofácies analisadas não apresentavam padrões de empilhamento reconhecíveis, não permitindo assim definir variações específicas do nível de base relativo. Foram separados três tratos no intervalo sin-rifte da Bacia de Campos (i) Trato de Sistemas de Início de Rifte; (ii) Trato de Sistemas de Alta Atividade tectônica e (iii) Trato de Sistemas de Baixa Atividade Tectônica. Assim, o arcabouço estratigráfico aqui proposto apresenta um padrão evolutivo que compreende reservatórios jamais testados em diversos locais ainda não explorados da Bacia de Campos, facilitando assim campanhas exploratórias futuras. / This work aims to establish a methodological and practical procedure for the stratigraphic using study seismic data of rift basins, focusing on tectonic stratigraphic analysis and seismofacies, specifically for rift basins. For this, we used the sedimentary deposits of the Lagoa Feia Group, Offshore Campos Basin, southeast continental margin Brazilian. The Lagoa Feia Group is characterized by siliciclastic, carbonate and evaporite sediments deposited during the rift and post-rift phases. 2D seismic lines, exploration wells with core and lithological logs were the data employer. Using the fundamental concepts of sismoestratigraphy, reflector patterns and lithologic data from wells three seismofacies were identified associated with the halfgraben fill of the rift phase: Seismofacies 1 (fault-border deposits) occurrence restricted to the fault borders in a well-defined area; Seismofacies 2 (fine-grained deposits) are widespread and grade laterally to seismofacies 3; Seismofacies 3 (grainstone and rudstone deposits) have restricted and erratic occurrences in both areas of the flexural margin, as well as in the deep areas of the basin, near the depocenter of the analyzed half-grabens. These seismofacies identified on the seismic lines of the Campos Basin have been transposed into selected lines of the Santos Basin, proved to be operational in the definition of potential reservoirs. A fourth distinct seismofacies with a punctual occurrence has been identified. This seismofacies is characterized by strongly discontinuous reflectors and amplitude reduction effects, being identified as hydrothermal vents. Aided by examples from the literature, ten hydrothermal vents were identified, characterized as dome and eye types. Pipes and intrusive bodies associated with these structures were also identified. Sequences stratigraphy concepts were adapted to the rift basins, in order to propose a chrono-stratigraphic framework, which included representative units of different events, with their bordering surfaces (stratigraphic surfaces) and in some cases functional surfaces (no precise stratigraphic control). The tectonic-stratigraphic framework of the rift sequence was divided into a pre-rift, syn-rift and post-rift stage. The syn-rift range has been subdivided based on the geometric patterns of the reflectors. The seismofacies analyzed no showed stacking patterns recognizable and did not allow the definition specific variations of base level. Were separated into three tectonic systems tracts (i) Rift initiation systems tract; (ii) High tectonic activity systems tract and (iii) Low tectonic activity systems tract. Thus, the stratigraphic framework proposed here presents an evolutionary pattern which comprises untested reservoirs in unexplored areas of the Campos Basin, thus facilitating future exploration campaigns.

O presente trabalho tem como objetivo estabelecer um procedimento metodológico e prático de estudo estratigráfico utilizando dados sísmicos, para bacias rifte, enfocando em análise tectônica e estratigráfica e sismofácies, especificadamente para bacias do tipo rifte. Para isso, foram utilizados os depósitos sedimentares do Grupo Lagoa Feia, Offshore da Bacia Campos, margem continental sudeste brasileira. O Grupo Lagoa Feia é caracterizado por sedimentos siliciclásticos, carbonáticos e evaporíticos depositados durante a fase rifte e pós-rifte. Linhas sísmica 2D, perfis litológico de poços exploratórios e testemunhos serviram como base de dados para suporte a este trabalho. Utilizando os conceitos fundamentais da sismoestratigrafia, padrão de refletores e dados litológico de poços, foram identificadas três sismofácies associados a meio-grabens da fase rifte: Sismofácies 1 (depósito de falha de borda) – tem sua ocorrência encaixada na falha de borda em uma zona ampla e bem definida; Sismofácies 2 (depósito de sedimentos finos) – amplamente identificada e grada lateralmente para a sismofácies 3; Sismofácies 3 (depósito de grainstones e rudstones) – têm ocorrência restrita e de ocorrência errática, tanto em zonas altas da margem flexural, quanto nas zonas profundas próximas do depocentro dos meiográbens analisados. Estas sismofácies identificadas nas linhas sísmica da Bacia de Campos foram transpostas para linhas selecionadas da Bacia de Santos, mostrandose operacional na definição de potenciais reservatórios. Uma quarta sismofácies distinta e de ocorrência pontual foi identificada. Esta sismofácies é caracterizada por forte descontinuidade nos refletores e efeitos de redução de amplitude, sendo identificada como vent hidrotermal. Auxiliado por exemplos da literatura, foram identificadas dez vents hidrotermais caracterizadas como do tipo dome e eye e identificados também, os dutos e corpos intrusivos associados a esta estrutura. Com os conceitos da estratigrafia de sequências adaptados para bacias do tipo rifte, foi proposto um arcabouço crono-estratigráfico que compreendeu unidades representativas de eventos distintos, com suas superfícies limítrofes (superfícies estratigráficas) e por vezes, superfícies funcionais (sem controle estratigráfico preciso). O arcabouço tectono-estratigráfico da sucessão rifte foi subdividido em uma fase prérifte, sin-rifte e pós-rifte. O intervalo sin-rifte foi subdividido com base nos padrões geométricos dos refletores, visto que as sismofácies analisadas não apresentavam padrões de empilhamento reconhecíveis, não permitindo assim definir variações específicas do nível de base relativo. Foram separados três tratos no intervalo sin-rifte da Bacia de Campos (i) Trato de Sistemas de Início de Rifte; (ii) Trato de Sistemas de Alta Atividade tectônica e (iii) Trato de Sistemas de Baixa Atividade Tectônica. Assim, o arcabouço estratigráfico aqui proposto apresenta um padrão evolutivo que compreende reservatórios jamais testados em diversos locais ainda não explorados da Bacia de Campos, facilitando assim campanhas exploratórias futuras. / This work aims to establish a methodological and practical procedure for the stratigraphic using study seismic data of rift basins, focusing on tectonic stratigraphic analysis and seismofacies, specifically for rift basins. For this, we used the sedimentary deposits of the Lagoa Feia Group, Offshore Campos Basin, southeast continental margin Brazilian. The Lagoa Feia Group is characterized by siliciclastic, carbonate and evaporite sediments deposited during the rift and post-rift phases. 2D seismic lines, exploration wells with core and lithological logs were the data employer. Using the fundamental concepts of sismoestratigraphy, reflector patterns and lithologic data from wells three seismofacies were identified associated with the halfgraben fill of the rift phase: Seismofacies 1 (fault-border deposits) occurrence restricted to the fault borders in a well-defined area; Seismofacies 2 (fine-grained deposits) are widespread and grade laterally to seismofacies 3; Seismofacies 3 (grainstone and rudstone deposits) have restricted and erratic occurrences in both areas of the flexural margin, as well as in the deep areas of the basin, near the depocenter of the analyzed half-grabens. These seismofacies identified on the seismic lines of the Campos Basin have been transposed into selected lines of the Santos Basin, proved to be operational in the definition of potential reservoirs. A fourth distinct seismofacies with a punctual occurrence has been identified. This seismofacies is characterized by strongly discontinuous reflectors and amplitude reduction effects, being identified as hydrothermal vents. Aided by examples from the literature, ten hydrothermal vents were identified, characterized as dome and eye types. Pipes and intrusive bodies associated with these structures were also identified. Sequences stratigraphy concepts were adapted to the rift basins, in order to propose a chrono-stratigraphic framework, which included representative units of different events, with their bordering surfaces (stratigraphic surfaces) and in some cases functional surfaces (no precise stratigraphic control). The tectonic-stratigraphic framework of the rift sequence was divided into a pre-rift, syn-rift and post-rift stage. The syn-rift range has been subdivided based on the geometric patterns of the reflectors. The seismofacies analyzed no showed stacking patterns recognizable and did not allow the definition specific variations of base level. Were separated into three tectonic systems tracts (i) Rift initiation systems tract; (ii) High tectonic activity systems tract and (iii) Low tectonic activity systems tract. Thus, the stratigraphic framework proposed here presents an evolutionary pattern which comprises untested reservoirs in unexplored areas of the Campos Basin, thus facilitating future exploration campaigns.

In June 2009, a 2.2 square mile 3-D high resolution seismic reflection survey was shot in southeastern Illinois in the Phillipstown Consolidated oilfield. A well was drilled in the 3-D survey area to tie the seismic to the geological data with a synthetic seismogram from the sonic log. The objectives of the 3-D seismic survey were three-fold: 1.) To image and interpret faulting of the Herald-Phillipstown Fault using drillhole-based geological and seismic cross-sections and structural contour maps created from the drillhole data and seismic reflection data, 2.) To test the effectiveness of imaging the faults by selected seismic attributes, and 3.) To compare spectral decomposition amplitude maps with an isochron map and an isopach map of a selected geologic interval (VTG interval). Drillhole and seismic reflection data show that various formation offsets increase near the main Herald-Phillipstown fault, and that the fault and its large offset subsidiary faults penetrate the Precambrian crystalline basement. A broad, northeast-trending 10,000 feet wide graben is consistently observed in the drillhole data. Both shallow and deep formations in the geological cross-sections reveal small horst and graben features within the broad graben created possibly in response to fault reactivations. The HPF faults have been interpreted as originally Precambrian age high-angle, normal faults reactivated with various amounts and types of offset. Evidence for strike-slip movement is also clear on several faults. Changes in the seismic attribute values in the selected interval and along various time slices throughout the whole dataset correlate with the Herald-Phillipstown faults. Overall, seismic attributes could provide a means of mapping large offset faults in areas with limited or absent drillhole data. Results of the spectral decomposition suggest that if the interval velocity is known for a particular formation or interval, high-resolution 3-D seismic reflection surveys could utilize these amplitudes as an alternative seismic interpretation method for estimating formation thicknesses. A VTG isopach map was compared with an isochron map and a spectral decomposition amplitude map. The results reveal that the isochron map strongly correlates with the isopach map as well as the spectral decomposition map. It was also found that thicker areas in the isopach correlated with higher amplitude values in the spectral decomposition amplitude map. Offsets along the faults appear sharper in these amplitudes and isochron maps than in the isopach map, possibly as a result of increased spatial sampling.

O presente trabalho tem como objetivo estabelecer um procedimento metodológico e prático de estudo estratigráfico utilizando dados sísmicos, para bacias rifte, enfocando em análise tectônica e estratigráfica e sismofácies, especificadamente para bacias do tipo rifte. Para isso, foram utilizados os depósitos sedimentares do Grupo Lagoa Feia, Offshore da Bacia Campos, margem continental sudeste brasileira. O Grupo Lagoa Feia é caracterizado por sedimentos siliciclásticos, carbonáticos e evaporíticos depositados durante a fase rifte e pós-rifte. Linhas sísmica 2D, perfis litológico de poços exploratórios e testemunhos serviram como base de dados para suporte a este trabalho. Utilizando os conceitos fundamentais da sismoestratigrafia, padrão de refletores e dados litológico de poços, foram identificadas três sismofácies associados a meio-grabens da fase rifte: Sismofácies 1 (depósito de falha de borda) – tem sua ocorrência encaixada na falha de borda em uma zona ampla e bem definida; Sismofácies 2 (depósito de sedimentos finos) – amplamente identificada e grada lateralmente para a sismofácies 3; Sismofácies 3 (depósito de grainstones e rudstones) – têm ocorrência restrita e de ocorrência errática, tanto em zonas altas da margem flexural, quanto nas zonas profundas próximas do depocentro dos meiográbens analisados. Estas sismofácies identificadas nas linhas sísmica da Bacia de Campos foram transpostas para linhas selecionadas da Bacia de Santos, mostrandose operacional na definição de potenciais reservatórios. Uma quarta sismofácies distinta e de ocorrência pontual foi identificada. Esta sismofácies é caracterizada por forte descontinuidade nos refletores e efeitos de redução de amplitude, sendo identificada como vent hidrotermal. Auxiliado por exemplos da literatura, foram identificadas dez vents hidrotermais caracterizadas como do tipo dome e eye e identificados também, os dutos e corpos intrusivos associados a esta estrutura. Com os conceitos da estratigrafia de sequências adaptados para bacias do tipo rifte, foi proposto um arcabouço crono-estratigráfico que compreendeu unidades representativas de eventos distintos, com suas superfícies limítrofes (superfícies estratigráficas) e por vezes, superfícies funcionais (sem controle estratigráfico preciso). O arcabouço tectono-estratigráfico da sucessão rifte foi subdividido em uma fase prérifte, sin-rifte e pós-rifte. O intervalo sin-rifte foi subdividido com base nos padrões geométricos dos refletores, visto que as sismofácies analisadas não apresentavam padrões de empilhamento reconhecíveis, não permitindo assim definir variações específicas do nível de base relativo. Foram separados três tratos no intervalo sin-rifte da Bacia de Campos (i) Trato de Sistemas de Início de Rifte; (ii) Trato de Sistemas de Alta Atividade tectônica e (iii) Trato de Sistemas de Baixa Atividade Tectônica. Assim, o arcabouço estratigráfico aqui proposto apresenta um padrão evolutivo que compreende reservatórios jamais testados em diversos locais ainda não explorados da Bacia de Campos, facilitando assim campanhas exploratórias futuras. / This work aims to establish a methodological and practical procedure for the stratigraphic using study seismic data of rift basins, focusing on tectonic stratigraphic analysis and seismofacies, specifically for rift basins. For this, we used the sedimentary deposits of the Lagoa Feia Group, Offshore Campos Basin, southeast continental margin Brazilian. The Lagoa Feia Group is characterized by siliciclastic, carbonate and evaporite sediments deposited during the rift and post-rift phases. 2D seismic lines, exploration wells with core and lithological logs were the data employer. Using the fundamental concepts of sismoestratigraphy, reflector patterns and lithologic data from wells three seismofacies were identified associated with the halfgraben fill of the rift phase: Seismofacies 1 (fault-border deposits) occurrence restricted to the fault borders in a well-defined area; Seismofacies 2 (fine-grained deposits) are widespread and grade laterally to seismofacies 3; Seismofacies 3 (grainstone and rudstone deposits) have restricted and erratic occurrences in both areas of the flexural margin, as well as in the deep areas of the basin, near the depocenter of the analyzed half-grabens. These seismofacies identified on the seismic lines of the Campos Basin have been transposed into selected lines of the Santos Basin, proved to be operational in the definition of potential reservoirs. A fourth distinct seismofacies with a punctual occurrence has been identified. This seismofacies is characterized by strongly discontinuous reflectors and amplitude reduction effects, being identified as hydrothermal vents. Aided by examples from the literature, ten hydrothermal vents were identified, characterized as dome and eye types. Pipes and intrusive bodies associated with these structures were also identified. Sequences stratigraphy concepts were adapted to the rift basins, in order to propose a chrono-stratigraphic framework, which included representative units of different events, with their bordering surfaces (stratigraphic surfaces) and in some cases functional surfaces (no precise stratigraphic control). The tectonic-stratigraphic framework of the rift sequence was divided into a pre-rift, syn-rift and post-rift stage. The syn-rift range has been subdivided based on the geometric patterns of the reflectors. The seismofacies analyzed no showed stacking patterns recognizable and did not allow the definition specific variations of base level. Were separated into three tectonic systems tracts (i) Rift initiation systems tract; (ii) High tectonic activity systems tract and (iii) Low tectonic activity systems tract. Thus, the stratigraphic framework proposed here presents an evolutionary pattern which comprises untested reservoirs in unexplored areas of the Campos Basin, thus facilitating future exploration campaigns.

This work examines several volume attributes extracted from 3D seismic data with the goal of seismic facies classification and lithology prediction in intraslope minibasins. The study area is in the Keathley Canyon protraction (KC), within the middle slope of the Northern Gulf of Mexico (GOM). It lays within the tabular salt and minibasins province downdip of the main Pliocene and Pleistocene deltaic depocenters. Interaction between sedimentation and mobile salt substrate lead to the emergence of many stratigraphic patterns in the intraslope minibasins. Interest in subsalt formations left above salt formations poorly logged. Facies classification using Artificial Neural Network (ANN) was applied in those poorly logged areas. The resultant facies classes were calibrated and used to predict the lithology of the recognized facies patterns in an intraslope minibasin, away from well control. Three types of facies classes were identified: Convergent thinning, convergent baselaping and bypassing. The convergent baselaping are found to be the most sand rich among all other facies.

The quantitative estimation of reservoir properties directly from seismic data is a major goal of reservoir characterization. Integrated reservoir characterization makes use of different varieties of well and seismic data to construct detailed spatial estimates of petrophysical and fluid reservoir properties. The advantage of data integration is the generation of consistent and accurate reservoir models that can be used for reservoir optimization, management and development. This is particularly valuable in mature field settings where hydrocarbons are known to exist but their exact location, pay, lateral variations and other properties are poorly defined. Recent approaches of reservoir characterization make use of individual seismic attributes to estimate inter-well reservoir properties. However, these attributes share a considerable amount of information among them and can lead to spurious correlations. An alternative approach is to evaluate reservoir properties using multiple seismic attributes. This study reports the results of an investigation of the use of multivariate seismic attributes to predict lateral reservoir properties of gross thickness, net thickness, gross effective porosity, net-to-gross ratio and net reservoir porosity thickness product. This approach uses principal component analysis and principal factor analysis to transform eighteen relatively correlated original seismic attributes into a set of mutually orthogonal or independent PC??s and PF??s which are designated as multivariate seismic attributes. Data from the N-sand interval of Vermilion Block 50 field, Gulf of Mexico, was used in this study. Multivariate analyses produced eighteen PC??s and three PF??s grid maps. A collocated cokriging geostaistical technique was used to estimate the spatial distribution of reservoir properties of eighteen wells penetrating the N-sand interval. Reservoir property maps generated by using multivariate seismic attributes yield highly accurate predictions of reservoir properties when compared to predictions produced with original individual seismic attributes. To the contrary of the original seismic attribute results, predicted reservoir properties of the multivariate seismic attributes honor the lateral geological heterogeneities imbedded within seismic data and strongly maintain the proposed geological model of the N-sand interval. Results suggest that multivariate seismic attribute technique can be used to predict various reservoir properties and can be applied to a wide variety of geological and geophysical settings.

The quantitative estimation of reservoir properties directly from seismic data is a major goal of reservoir characterization. Integrated reservoir characterization makes use of different varieties of well and seismic data to construct detailed spatial estimates of petrophysical and fluid reservoir properties. The advantage of data integration is the generation of consistent and accurate reservoir models that can be used for reservoir optimization, management and development. This is particularly valuable in mature field settings where hydrocarbons are known to exist but their exact location, pay, lateral variations and other properties are poorly defined. Recent approaches of reservoir characterization make use of individual seismic attributes to estimate inter-well reservoir properties. However, these attributes share a considerable amount of information among them and can lead to spurious correlations. An alternative approach is to evaluate reservoir properties using multiple seismic attributes. This study reports the results of an investigation of the use of multivariate seismic attributes to predict lateral reservoir properties of gross thickness, net thickness, gross effective porosity, net-to-gross ratio and net reservoir porosity thickness product. This approach uses principal component analysis and principal factor analysis to transform eighteen relatively correlated original seismic attributes into a set of mutually orthogonal or independent PC??s and PF??s which are designated as multivariate seismic attributes. Data from the N-sand interval of Vermilion Block 50 field, Gulf of Mexico, was used in this study. Multivariate analyses produced eighteen PC??s and three PF??s grid maps. A collocated cokriging geostaistical technique was used to estimate the spatial distribution of reservoir properties of eighteen wells penetrating the N-sand interval. Reservoir property maps generated by using multivariate seismic attributes yield highly accurate predictions of reservoir properties when compared to predictions produced with original individual seismic attributes. To the contrary of the original seismic attribute results, predicted reservoir properties of the multivariate seismic attributes honor the lateral geological heterogeneities imbedded within seismic data and strongly maintain the proposed geological model of the N-sand interval. Results suggest that multivariate seismic attribute technique can be used to predict various reservoir properties and can be applied to a wide variety of geological and geophysical settings.

Multicomponent seismic imaging techniques improve geological interpretation by providing crucial information about subsurface characteristics. These techniques deliver different images of the same subsurface using multiple waveforms. Compressional (P) and shear (S) waves respond to lithology and fluid variations differently, providing independent measurements of rock and fluid properties. Joint interpretation of multicomponent images requires P-wave and S-wave events to be aligned in depth. The process of identifying P and S events from the same reflector is called depth-registration. The purpose of this investigation is to illustrate procedures for depth-registering P and S seismic data when the most fundamental information needed for depth-registration – reliable velocity data – are not available. This work will focus on the depth-registration of a 9-component 3-dimensional seismic dataset targeting the Sycamore formation in Stephens County, Oklahoma. The survey area – 16 square miles – is located in Sho-Vel-Tum oilfield. Processed P-P, SV-SV, and SH-SH wave data are available for post-stack analysis. However, the SV-data volume will not be interpreted because of its inferior data-quality compared to the SH-data volume. Velocity data are essential in most depth-registration techniques: they can be used to convert the seismic data from the time domain to the depth domain. However, velocity data are not available within the boundaries of the 9C/3D seismic survey. The data are located in a complex area that is folded and faulted in the northwest part of the Ardmore basin, between the eastern Arbuckle Mountains and the western Wichita Mountains. Large hydrocarbon volumes are produced from stratigraphic traps, fault closures, anticlines, and combination traps. Sho-Vel-Tum was ranked 31st in terms of proved oil reserves among U.S. oil fields by a 2009 survey. I will interpret different depth-registered horizons on the P-wave and S-wave seismic data volumes. Then, I will present several methods to verify the accuracy of event-registration. Seven depth-registered horizons are mapped through the P-P and SH-SH seismic data. These horizons show the structural complexity that imposes serious challenges on well drilling within the Sho-Vel-Tum oil field. Interval Vp/Vs – a seismic attribute often used as lithological indicator – was mapped to constrain horizon picking and to characterize lateral stratigraphic variations. / text

O desenvolvimento de soluções para a classificação de ambientes de sedimentação ainda é um desafio, sobretudo em ambientes de deposição carbonáticos. Em reservatórios de óleo e gás offshore, onde a geometria dos ambientes deposicionais é fundamental para a estimativa de viabilidade técnica e econômica de exploração e produção, a discriminação destes ambientes depende de dados indiretos. Nesse sentido, a sísmica de reflexão e seus respectivos atributos funcionam como robusta ferramenta interpretativa. Grandes reservas de petróleo offshore se encontram em rochas carbonáticas constituídas, sobretudo, por calcita e dolomita. Estes minerais, no entanto, não apresentam resposta sísmica contrastante, já que a diferença de velocidade entre tais minerais é inexpressiva. A utilização da amplitude sísmica, unicamente, não possibilita diferenciar propriedades das rochas carbonáticas, tal como ocorre com rochas siliciclásticas. Compactação e hidrotermalismo são fatores pós-deposicionais que influenciam na alteração das características de rochas carbonáticas, e apresentam difícil detecção nas seções sísmicas. Tais fatores necessitam de uma abordagem que envolva as propriedades dos múltiplos atributos sísmicos para a respectiva caracterização. A técnica Self-Organizing Maps (SOM) consiste em ferramenta de análise e visualização de dados vetoriais dentro do espaço dimensional definido pelas variáveis. Trata-se de abordagem multi-atributos em que a identificação e classificação das amostras ocorre de maneira não supervisionada. Neste trabalho são utilizados dados sísmicos dos quais foi extraída a amplitude sobre um horizonte interpretado. Foram utilizados também os atributos do traço sísmico complexo, tais como: envelope, fase instantânea e frequência instantânea, além da impedância acústica e derivada espacial. Estes atributos foram escolhidos em função das características geológicas que representam. Além disso, tais atributos têm sido utilizados em outros trabalhos de classificação de fácies sísmicas. Após uma primeira análise SOM, tendo em vista o realce dos atributos de entrada, foi aplicada a Análise por Principais Componentes (APC). Com base nos componentes obtidos, foi realizada uma segunda análise SOM, obtendo-se assim os resultados que mais corresponderam ao sistema deposicional analisado. Foram identificados também clinoformas nos dados sísmicos, que apresentam correlação com a classificação dos resultados assim como um mapa de distribuição de rochas carbonáticas foi elaborado pela interpretação das classes identificadas correlacionando-as ao poço 1-SPS-0029 associando-o ao modelo de deposição de uma plataforma carbonática. / Developing solutions for classifying sedimentation environments is still quite a challenge, particularly in carbonate sites. It\'s crucial to use indirect data to differentiate the geometry of depositional environment of oil and gas offshore reservoirs when estimating the productions under technical and economical sights. Therefore, the seismic and its attributes work like a powerful interpretative tool. A great amount of oil reservoirs can be found in carbonate rocks, whose main constitution minerals are calcite and dolomite. Those minerals, however, don\'t offer a significantly contrasting response to seismic. The seismic amplitude, by itself, isn\'t a good property estimation to be used on carbonate rocks, as it is on the siliciclastic rocks. Compactation and hydrothermalism are post-depositional influencers on the alteration of carbonate rocks features, and they present a difficult detection on seismic sections. Those factors will need multiple seismic attributes to respective characterization. Self-Organizing Maps (SOM) appear as a tool for analysis and visualization of vectorial data within the dimensional space defined by the variables. That\'s a multi-featured approach whose samples identification and classification will occur in a non-supervisioned way. The use of SOM in this paper do not intend to substitute the interpretation of the results, but aims to pop up the intrinsic relations between used attributes. It has been interpreted a horizon, from which it was possible to take the amplitude on seismic as a first attribute. There have also been used acoustic impedance, spatial derivative and complex seismic trace attributes, like reflection strength, instant phase and instant frequency. Such attributes have been chosen by reflecting geological characteristics. After a previous SOM analysis, aiming to highlight raw attributes, there was applied the Principal Components Analysis (PCA). Based on obtained components, a second SOM was performed, leading to results that best corresponded to the depositional system analyzed. Besides, there were identified clinoforms on seismic data, which keep relation with classification of the result.