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Buland, Arild. "Bayesian Seismic AVO Inversion." Doctoral thesis, Norwegian University of Science and Technology, Department of Mathematical Sciences, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-2005.
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Seismic analysis is a key element in successful exploration and production of natural resources. During the last decades, seismic methodology has had a significant progress with respect to both acquisition, processing and analysis. Despite all the new tec hnology, the uncertainty related to seismic analysis is still large, and even worse, the uncertainty is often not systematically assessed.
In this thesis, the uncertainty aspect of seismic amplitude versus offset (AVO) in version is assessed using a Bayesian approach to inversion. The main objective is to estimate elastic material parameters with associated uncertainty from large seismic data sets, but the in versionproblem also includes estimation of seismic wavelets and the noise level. State of the art statistical methodology is applied to attack these current and crucial geophysical problems. The core part of the work is presented in four separate papers written for geophysical journals, constituting Chapter 2 through 5 in this thesis. Each of the papers is self-contained, with exception of the references which are placed in a separate bibliography chapter.
Paper I, II and III: copyright SEG Paper III: copyright EAGE
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Gislason, Gardar. "Effect of Petrophysical Parameters on Seismic Waveform Signatures : Review of Theory with Case Study from Frigg Delta Oil Field, Norway." Thesis, Uppsala universitet, Geofysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303793.
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Conventional AVO analysis has been used for the past 4 decades to aid in locating oil and gas reservoirs for extraction. It is, however, not possible to use it to acquire information on the porosity of the rock, the fluid saturation or other important petrophysical parameters. In this thesis, I study the effects of attenuation on seismic waveform signatures, due to wave induced fluid-flow. In the first part of the thesis, 2 models were used to synthetically model the attenuation caused by the wave induced fluid-flow: White's model and the double-porosity dual-permeability (DPDP) model. The parameters used for modeling were both synthetic and acquired from real well data of a known oil field off the coast of Norway. White's model was found to model relatively high attenuation (5%) for intermediately consolidated gas reservoirs while oil saturated intermediately consolidated reservoirs showed such low attenuation (0.3%) that it is easy to say that for the real-world situation it would not be detected. The DPDP model seemed to be able to better describe the attenuation and gave attenuations up to 10% for an intermediately consolidated oil reservoir, but due to lack of parameters from well data it was not sufficiently able to model the real-world situation. The synthetic data, however, show interesting characteristics and it is therefore recommended that more and detailed well parameters be acquired if the research should continue. For the second part, Svenska Petroleum Exploration AB and Det Norske Oljeselskap ASA provided stacked seismic data that were spectrally analyzed for hints of attenuation variation with frequency (using Fourier Transform and Complex Spectral Decomposition). Twelve locations, on the stacked seismic cube, were analyzed; six oil saturated; and six (assumed) water saturated. At each location, a main trace was selected along with the two nearby traces on each side of it (five in total). The Complex Spectral Decomposition method seemed unable to correctly break down the stacked section's signal, which is why Fourier Transform was used for further analysis. The frequency analysis showed a peak at ~30 Hz for both oil and water saturated reservoirs which seems like a characteristic frequency of the source, but that was unfortunately not confirmed and not enough time was available to test the assumption. The Fourier transform seems to show some difference between oil and water saturated traces, but that could well be because of lithological differences and not the pore fluid. It is therefore recommended, if research is to be continued, that 4D seismic data is used to analyze the same location with respect to time. It is also recommended that pre-stack or shot data be used as information is lost in stacked data.Konventionell AVO-analys har använts under fyra deceniär som ett hjälpmedel för att finna olje- och gasreserver, men tekniken kan även användas för att erhålla information om bergets porositet, vätskemättnaden och andra viktiga petrofysiska parametrar. I denna avhandlingen har jag studerat hur våginducerat vätskeflöde påverkar dämpningen av den seismiska vågformssignaturen. I den första delen av avhandlingen användes två metoder för att syntetisk modellera dämpning orsakad av våginducerat vätskeflöde: "White's modell" och "double-porosity dual-permeability (DPDP) modellen". Både syntetiska parametrar och verkliga parametrar från borrhålsdata från ett känt norskt oljefält användes vid modelleringen. White's modell visade sig modellera relativt kraftig dämpning (5%) för medelstarkt konsoliderade gasreservoarer medan för oljereservoarer med motsvaranda konsolidering dämpningen var så låg (0.3%) att det är uppenbart att i en verklig situation skulle dämpningen inte vara mätbar. DPDP modelleringen verkar vara bättre på att beskriva dämpningen och gav dämpningar upp till 10% för en medelstarkt konsoliderad oljereservoar. Brist på parametrar från borrhålsdata gjorde att det inte var möjligt att på ett tillfredställande sätt modellera en verklig situation.Dock visade syntetisk data intressant karaktäristik och det rekommenderas därför att mer och detaljerade borrhålsparametrar mäts om ytterligare forskning om detta ska genomföras. För den andra delen av avhandlingen har Svenska Petroleum Exploration AB och Det Norske Oljeselskap ASA bidragit med stackad seismisk data som även var spectralanalyserad för indikationer på frekvensberoende dämpningsvariationer (utfört med fouriertransform och komplex spectraldekomposition). Tolv områden på den stackade kuben analyserades; sex oljemättade och sex som antogs vara vattenmättade. I varje område valdes en huvudtracé och de två närmaste tracéerna på vardera sida (totalt fem tracéer). Metoden med komplex spectraldekomposition klarade inte att analysera signalen från den stackade sektionen, varför fouriertransform användes för vidare analys. Frekvensanalysen gav en topp vid ~30 Hz för både olje- och vattenmättade reservoarer vilket tycks vara en karaktäristisk frekvens för källan. Detta kunde tyvärr inte bekräftas och tiden räckte inte till för att testa antagandet. Fouriertransformen tycks visa en viss skillnad mellan olje- och vattenmättade tracéer, men det kan också bero på skillnad i litologin snarare än porvätskan. Där för rekommenderas vid fortsättning på denna forskning att 4D seismisk data används för att analysera samma område men med data från olika tidpunkter. Det rekommenderas även att ostackad eller råa skott-data används eftersom väsentlig information kan försvinna när data stackas.
Advisor present: Dr. Chris Juhlin
Examiner: Dr. Milovan Urosevic
Opponent: Álvaro Polín Tornero
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Skopintseva, Lyubov. "Exploring the potential of long offset reflections in AVO inversion and AVO analysis." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15380.
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Analysis of seismic reflection amplitudes versus offset (AVO) is one of common techniques widely exploited in the industry for reservoir characterization. For the last two decades a lot of approaches to analysis, inversion and interpretation of AVO data have been developed. Existing modifications valid for weak-contrast interfaces were successfully employed for conventional reservoirs. The growing interest of the industry to unconventional reservoirs, such as stiff-carbonate reservoirs, heavy oil traps and reservoirs close to salts domes - associated with strong-contrast interfaces and critical angles - implies the development of AVO techniques valid prior and beyond the critical angle. It has been reported in literature that near- and post-critical reflections have a potential to be employed as an additional source of information about the media. However, the use of these reflections is limited by the inability of well-known Zoeppritz equations to explain phenomena observed around and beyond the critical angle. The aim of the thesis is to investigate phenomena observed at the reflected data around and beyond the critical angle, understand their potential from the AVO analysis and inversion point of view and develop a long-offset AVO inversion approach valid for strong-contrast interfaces. The theory of effective reflection coefficients is exploited as a mathematical apparatus providing an adequate description of phenomena observed at near- and post-critical reflections. The thesis consists of five papers, where four major issues are addressed. The sensitivity of the reflection coefficient to isotropic and HTI media parameter changes prior to and beyond the critical angle is studied. The long-offset AVO inversion approach valid prior to and beyond the critical angle, strong-contrast and curved interfaces is developed and tested on synthetic data obtained for models with a single interface of various curvatures. Frequency effects in pre- near- and post-critical domains observed on the data of physical modeling are studied from the point of view of potential exploiting. Finally, the sensitivity of long-offset AVO inversion to errors related to overburden velocity misinterpretation is analyzed.
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Ross, Christopher P. "AVO limitations near salt structures." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/31010.
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Alhussain, Mohammed. "Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/267.
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A spherical wave AVO response is investigated by measuring ultrasonic reflection amplitudes from a water/Plexiglas interface. The experimental results show substantial deviation from the plane-wave reflection coefficients at large angles. However there is an excellent agreement between experimental data and full-wave numerical simulations performed with the reflectivity algorithm. By comparing the spherical-wave AVO response, modeled with different frequencies, to the plane-wave response, I show that the differences between the two are of such magnitude that three-term AVO inversion based on AVA curvature can be erroneous. I then propose an alternative approach to use critical angle information extracted from AVA curves, and show that this leads to a significant improvement of the estimation of elastic parameters. Azimuthal variation of the AVO response of a vertically fractured model also shows good agreement with anisotropic reflectivity simulations, especially in terms of extracted critical angles which indicated that (1) reflection measurements are consistent with the transmission measurements; (2) the anisotropic numerical simulation algorithm is capable of simulating subtle azimuthal variations with excellent accuracy; (3) the methodology of picking critical angles on seismograms using the inflection point is robust, even in the presence of random and/or systematic noise.
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Ivanov, Elena. "A feasibility study of three term AVO /." Title page, abstract and table of contents only, 2002. http://web4.library.adelaide.edu.au/theses/09SB/09sbi934.pdf.
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Shrestha, Rajendra K. "3-D AVO analysis : a novel approach /." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1992.
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Alhussain, Mohammed. "Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations." Curtin University of Technology, Department of Exploration Geophysics, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17537.
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A spherical wave AVO response is investigated by measuring ultrasonic reflection amplitudes from a water/Plexiglas interface. The experimental results show substantial deviation from the plane-wave reflection coefficients at large angles. However there is an excellent agreement between experimental data and full-wave numerical simulations performed with the reflectivity algorithm. By comparing the spherical-wave AVO response, modeled with different frequencies, to the plane-wave response, I show that the differences between the two are of such magnitude that three-term AVO inversion based on AVA curvature can be erroneous. I then propose an alternative approach to use critical angle information extracted from AVA curves, and show that this leads to a significant improvement of the estimation of elastic parameters. Azimuthal variation of the AVO response of a vertically fractured model also shows good agreement with anisotropic reflectivity simulations, especially in terms of extracted critical angles which indicated that (1) reflection measurements are consistent with the transmission measurements; (2) the anisotropic numerical simulation algorithm is capable of simulating subtle azimuthal variations with excellent accuracy; (3) the methodology of picking critical angles on seismograms using the inflection point is robust, even in the presence of random and/or systematic noise.
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Wilson, Adam. "Theory and methods of frequency-dependent AVO Inversion." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4740.
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Amplitude-versus-offset, AVO, approximations allow the estimation of various properties from pre-stack seismic gathers. Recently it has been suggested that fluid mobility is a controlling factor in pore pressure equalisation and can result in anomalous velocity dispersion in the seismic bandwidth. However, current approximations all assume an elastic subsurface and are unable to account for velocity dispersion. I have applied existing methodologies to a real dataset to qualitatively detect and interpret spectral amplitude anomalies. Three areas had AVO and spectral signature consistent with frequency-dependent AVO theory. The results suggest that it is feasible to measure such effects on real data in the presence of random noise. It would imply that the relaxation parameter, tau, is larger in the field than has been measured in water-saturated real and synthetic sandstones in the laboratory. I extended a two-term AVO approximation by accounting for velocity dispersion and showed how the resultant reflection coefficient becomes frequency-dependent. I then used this to measure P- and S-wave reflectivity dispersion using spectrally-balanced amplitudes. The inversion was able to quantify the affect of the P-wave velocity dispersion as an instantaneous effect on the reflection. NMO stretch was an issue at the far offsets and I limited myself to the near offsets and effectively measured only the P-wave reflectivity dispersion. I showed how the P-wave reflectivity dispersion signs depend on the AVO classification of the reflection whilst the magnitude depends on the crack density of my model. I showed how the effect of noise and thin-bed tuning can enter uncertainties into the interpretation of spectral anomalies. Whilst it is possible to detect frequency-dependent AVO signatures on pre-stack gathers, the interpretation remains non-unique. I have quantitatively measured a new physical property, reflectivity dispersion, from pre-stack seismic data. I have presented a method of detecting and measuring velocity dispersion in pre-stack gathers but there remain ambiguities in the interpretation of such results. The approach incorporates spectrally decomposed data in an extended AVO inversion scheme. Future work should investigate the application of the methodology to a real seismic dataset.
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Ellison, Shelley J. "Modeling Offset-Dependent Reflectivity for Time-Lapse Monitoring of Water-Flood Production in Thin-Layered Reservoirs." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/34058.
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Seismic time-lapse monitoring of production is an important tool used to efficiently drain a hydrocarbon reservoir. Repeat seismic surveys may be used, because the seismic method is sensitive to the reservoir fluid. A prominent seismic attribute is the reflectivity (or amplitude) as a function of offset (AVO) which strongly depends on material properties, and hence, on the pore fluid. Repeat surveys, however, are very costly. To reduce the risks, the repeat survey is simulated on a computer for a number of different scenarios. Hence, the objectives of this study are to predict the seismic responses after five years of production of the reservoirs at the well locations, correlate the seismic attributes to fluid conditions in the reservoirs, assess the detectability of changes in AVO attributes due to changes in fluid conditions, and determine which attribute is more diagnostic of fluid changes.
Petrophysical models were generated for different pore fluids using well logs from a field in the Gulf of Mexico. Synthetic seismograms were then calculated using a layerstack scheme to study the effects of the reservoir fluids on AVO. Compared to idealized half-space models, it was found that the AVO responses are contaminated by the overburden and the thinness of the reservoir. In order to remove transmission loss due to overburden effects, the synthetic AVO curves were scaled by normalizing an overburden-over-half-space model to an idealized analytical Zoeppritz model. In a second step, an offset-dependent overburden correction was applied using a low order polynomial, which was fitted to the amplitude ratios between the overburden/half-space model and the idealized model. Finally, a zero-offset tuning correction was applied.
The results of the AVO analyses showed that some errors were unresolved using the applied overburden and tuning corrections, and amplitudes at large offsets were possibly contaminated by multiples and converted waves. Since there is no shallower production or steam injection for this particular field, the repeat surveys should have the same overburden, tuning, multiple-related and converted wave contamination. It appears reasonable to assume that any changes in amplitude between the repeat surveys would be due to fluid saturation changes. Therefore, it was concluded that it is not necessary to attempt to remove the overburden and tuning effects.
Results from the AVO analyses of the uncorrected models showed that AVO attributes should be a useful tool to detect reservoir conditions during the production of the field. Generally, the water-flood changes the AVO by decreasing the intercept and increasing the gradient from the in-situ oil/gas cases. The relative changes in both intercept and gradient due to the water-flood are detectable assuming a 20% relative-change detection threshold, and gradient is more diagnostic because the relative change in gradient is very large compared to that for intercept.Master of Science
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Xu, Yong. "AVO developments applied to Blackfoot 3C-2D broadband line." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/MQ49664.pdf.
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Eggen, Katharina Banschbach. "AVO Analysis of Turbidite Reservoir Rocks in the Alvheim Field." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18727.
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The Alvheim reservoir is a turbidite reservoir, which means that the complex deposition makes it a difficult reservoir to perform predictions regarding reservoir content on. In the preceding project work (Eggen 2012) AVO analyses were performed on the twelve modelled scenarios that can be present in a turbidite reservoir. These modelled scenarios were to be compared with the analyses performed on the real data in this master’s thesis to see if the modelled scenarios can help to predict what answers to expect from the analyses performed on the real data. One post-stack data set consisting of Near and Far stacks covering the whole Alvheim field including all three hydrocarbon discoveries, and one pre-stack data set focusing on the oil discovery named Kneler were available for this thesis in addition to well logs from well 25/4-7. Naturally, it was the Kneler oil discovery that was focused on, and on the gathers from the pre-stack data the top reservoir could be identified by a clear AVO effect. Different AVO analyses were performed on this AVO effect and the results were compared with the results obtained from the project work. In addition to performing AVO analyses on the data it was interesting to see if it was possible to see how the reservoir changed when moving away from the well location on the seismic data. To increase the signal to noise ratio, super gathers around the well location were created in addition to super gathers at some distance away from the well to see if there were changes that were noticeable on the seismic.The AVO analysis was performed on the top oil sand (top reservoir) in the Heimdal Member located in the Lista Formation. An AVO crossplot was created from both data sets, where the area around the Kneler discovery was picked by hand on the post-stack data set to match the area that was plotted from the pre-stack data. The crossplot created from the post-stack data showed the best deviation from the background trend out of the two, and the anomaly could be classified as a class III AVO anomaly. It was also performed an AVO gradient analysis on the AVO effect on a pre-stack seismic gather and on a synthetic seismic gather created with a normal Ricker wavelet and velocities taken from well 25/4-7. Both AVO curves from these analyses had a negative intercept and a negative gradient, which also could classify them as a class III AVO anomaly. It was known in advance that the upper part of the reservoir consisted of unconsolidated interbedded sand-shale and it was expected that the results would match the results obtained from the modelled scenario of the unconsolidated interbedded sand-shale. However, this was not completely the case and the results from the analyses of the real data turned out to match the analyses for the modelled unconsolidated massive sandstone. Even if the analyses from this master’s thesis do not match the expected analyses performed in the preceding project work, they can be said to be correct. The error in comparison is due to the fact that the analyses in this master’s thesis are performed on the top of a section of unconsolidated interbedded sand-shale, but the top layer is actually a layer of unconsolidated massive sandstone. This means that when making assumptions it should not be taken for granted that the real data will match the modelled data, especially not if there are uncertainties related to the assumptions the modelling is based on.
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Davólio, Alessandra 1980. "Aproximações para os coeficientes de reflexão e analise de AVO." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307608.
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Orientador: Lucio Tunes dos SantosDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
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Resumo: O estudo dos coeficientes de reflexão, de suas aproximações e consequentemente da análise de AVO (do inglês, Amplitude Variation with Offset) desenvolve um papel bastante importante na indústria do petróleo, por auxiliar na descrição litológica da região de interesse. Neste trabalho, inicialmente abordamos as principais idéias envolvidas na dedução das equações dos coeficientes de reflexão PP (ondas P incidente e P refletida) e PS (ondas P incidente e S refletida). Na sequência, são apresentadas diferentes aproximações para estas equações, seguidas de uma análise do comportamento das mesmas quando comparadas entre si e entre suas respectivas expressões exatas. Introduzimos uma nova aproximação para o coeficiente de reflexão PS similar à impedância de reflexão do coeficiente PP proposta recentemente. Finalizamos o trabalho discutindo o conceito de inversão de dados, avaliando a precisão dos indicadores apresentados, e fazendo um breve sumário da tradicional análise de AVO
Abstract: The study of the reflection coefficients, their approximations and the AVO (Amplitude Variation with Offset) analysis plays an important role in the oil industry as they can help to describe the interest region lithology. The first part of this work deals with the main ideas of the deduction of the reflection coefficients PP (P incident and P reflected waves) and PS (P incident and S reflected waves). Then, different approximations for these equations are presented, followed by a discussion of their behavior when compared among them and with their exact expressions. We introduce a new approximation for the reflection coefficient PS similar to the reflection impedance of PP coefficient proposed recently. To conclude, some indicators and their accuracy are discussed and a brief summary about the traditional AVO analysis is presented.
Mestrado
Mestre em Matemática Aplicada
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MENDES, Ana Cristina Marques. "Inversão quadrática de dados de AVO usando algoritmo de Marquardt." Universidade Federal do Pará, 2004. http://repositorio.ufpa.br/jspui/handle/2011/5817.
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Neste trabalho são apresentadas expressões exatas e aproximações quadráticas das conhecidas equações de Knott-Zöeppritz, que calculam as amplitudes dos coeficientes Rpp e Rsp em termos dos contrastes médios relativos, bem como é procedida a inversão dos parâmetros de dados de AVO a partir destas aproximações quadráticas. Nesta inversão é utilizado o algoritmo de Levenberg-Marquardt, e são considerados apenas os eventos refletidos Rpp e convertidos Rsp, não associados. Nos estudos dos parâmetros físicos dos meios contrastes de impedância (δz), módulo de cisalhamento (δμ) e velocidade da onda p (δα), verificou-se quais desses parâmetros podem ser invertidos. Os resultados obtidos mostram que o contraste de impedância (δz) é muito bem resolvido estando ele relacionado com o contraste de velocidade da onda p (δα) ou com o contraste de cisalhamento (δμ), no caso de eventos refletidos considerando modelos de alto, moderado e baixo contrastes. Por outro lado ao se fixar o contraste de impedância e relacionar os outros dois parâmetros em consideração, os resultados mostram que esses são mal resolvidos, ou seja, a região de ambiguidade torna-se muito grande e os parâmetros tornam-se ambíguos e instáveis. No caso do evento convertido e na combinação do evento refletido com o convertido, para os modelos de baixo e moderado contrastes, (δz) é muito bem resolvido, caso que não acontece para modelo de alto contraste. Diante desses resultados verifica-se que no procedimento de inversão quadrática de dados de AVO, fixado (δμ), a recuperação dos dois parâmetros variados é muito boa, no caso do evento refletido, e razoavelmente boa no caso do evento convertido, por esse motivo optou-se pela fixação do módulo de cisalhamento.
In this work, the exact and quadratic approach expression of Knott-Zöeprtiz are presented, as well as its coefficients, amplitudes, Rpp and Rsp, respectively, all of them as a function of the relative contrast, as well as the inversion of quadratic parameters of AVO data. In this inversion of the quadratic parameters, we have used the non-linear Levenberg-Marquadt algorithm, considering only converted and reflected events, either in the non-combined form. In the study of the physical parameters impedance contrast, shear modulus and P wave velocity, we have werified which of those parameters can be effectively inverted. The results have shown that the impedance contrast (δz) is very well solved when it is related with the P wave velocity contrast (δα) or with the shear contrast (δμ), considering reflected events in the case of high, moderate and low model contrasts. On the other hand, when the impedance constrast is fixed and the two other parameters in consideration are related, the results show that these parameters are bad solved, e.g., the ambiguity region becomes large and the parameters become ambiguous and unstable. In the case of a converted event and in the combination of converted and reflected events, considering low and moderate contrast models (δz) is well solved, which is not the case when we consider a high contrast model.
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Larsen, Jeffrey A. "AVO analysis by simultaneous P-P and P-S weighted stacking." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0021/MQ49632.pdf.
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Limacher, Romaric Davy. "Investigation into the applicability of AVO techniques to coal mine exploration." Thesis, Heriot-Watt University, 2011. http://hdl.handle.net/10399/2493.
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AVO (for Amplitude Versus Offset) is a seismic technology known in the oil industry for its ability to differentiate gas sands (over oil producing reservoirs) from wet sands (over non-producing reservoirs) in the Gulf of Mexico. Its applicability to a broad range of exploration fields has led to its potential application within the ADEMA (Advances in Exploration Methods and Applications) project being considered. Within the frame of this project, this PhD thesis assesses the ability of AVO to detect a difference between Mudstone and Sandstone roofs over a 6 meters thick coal seam, in the region of Daw Mill (UK). It moreover presents a modification of a triaxial cell aimed at calibrating AVO in the laboratory, and thereby improving the quality of AVO analysis in general. The analysis presented in this PhD thesis leads to the conclusion that in this region, the particular rock properties can lead to a signal difference detectable by AVO. However, analysis of seismic data confirmed that tuning effect interferes with these distinct signals, and prevents AVO technology to differentiate mudstone from sandstone roofs. Finally, this thesis proposes different technical recommendations for successfully running a test with the modified triaxial cell in future.
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Hennenfent, Gilles, and Felix J. Herrmann. "Three-term amplitude-versus-offset (avo) inversion revisited by curvelet and wavelet transforms." Society of Exploration Geophysicists, 2004. http://hdl.handle.net/2429/615.
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We present a new method to stabilize the three-term AVO inversion using Curvelet and Wavelet transforms. Curvelets are basis functions that effectively represent otherwise smooth objects having discontinuities along smooth curves. The applied formalism explores them to make the most of the continuity along reflectors in seismic images. Combined with Wavelets, Curvelets are used to denoise the data by penalizing high frequencies and small contributions in the AVO-cube. This approach is based on the idea that rapid amplitude changes along the ray-parameter axis are most likely due to noise. The AVO-inverse problem is linearized, formulated and solved for all (x, z) at once. Using densities and velocities of the Marmousi model to define the fluctuations in the elastic properties, the performance of the proposed method is studied and compared with the smoothing along the ray-parameter direction only. We show that our method better approximates the true data after the denoising step, especially when noise level increases.
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Pérez, Maria Auxiliadora. "Detection of fracture oreientation using azimuthal variation of P-wave AVO responses." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/55051.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1997.Includes bibliographical references (leaves 92-95).
by Maria Auxiliadora Pérez.
M.S.
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Holm, Andreas. "Estimation of Resrvoir Properties by Joint Inversion of Seismic AVO and CSEM data." Thesis, Norwegian University of Science and Technology, Department of Mathematical Sciences, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9622.
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Porosity and water saturation in a horizontal top-reservoir are estimated from seismic AVO (Amplitude Versus Offset) data and Controlled Source Electromagnetic (CSEM) data jointly. A model connecting porosity and saturation to both AVO effects and to the phase shift of electromagnetic signals is constructed. In this model, Gassmann's equations, Archie's law, Zoeppritz' equations and ray-tracing is involved. We use a Bayesian approach to solve the inversion problem, and the solution is given as posterior distributions for the parameters of interest. We also investigate the noise levels in the two types of data, and how these affect the estimates of the reservoir properties. Gaussian assumptions and linearizations are made to ensure analytically tractable posterior distributions for porosity and saturation, and a Gibbs sampler is used to explore the joint posterior for porosity, saturation and noise levels. The method is applied to both synthetic data, and field data from the Troll gas field. The results from the joint inversion are compared to results from using seismic data exclusively and a clear improvement is found in the estimates of the synthetic case. The results from the Troll data are more ambiguous, probably caused by the problem of picking seismic data along the top-reservoir and inaccuracies in the fixed parameters in the geophysical forward model.
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Haktorson, Hilde. "Estimation of Anisotropy Parameters and AVO modeling of the Troll Field, North Sea." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19099.
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In the work of this Master's thesis, the anisotropy parameters, epsilon and delta, for the reservoir and the cap rock on the Troll Field have been estimated. This was done using well logs from 35 wells, including the P-wave sonic log and the inclination angle log of the wellbore. The velocity from the sonic log and the inclination angle were applied to a second order polynomial equation, which includes the anisotropy parameters.The Matlab software was utilized to perform the calculations and to generate plots necessary to estimate the parameters. To obtain more reliable results, different filters were applied to the data set for both the reservoir and the cap rock. The filters consisted of different intervals of porosity, acoustic impedance and depth, both individually and combined in different ways. In advance of the filtering, histograms were made for porosity, acoustic impedance and depth to look at the distribution of each, in order to find the range the different parameters could be filtered for.This process resulted in the following estimations of the anisotropy parameters for the reservoir: epsilon = -0.08 and delta = -0.03. The anisotropy parameters for the cap rock, which is a shale in most of the wells, was estimated as follows: epsilon = 0.11 and delta = 0.06. These parameters were applied in an AVO analysis, performed for the vertical well 31/2-L-41. An approximation using 3-term Shuey equation was applied for this purpose. The anisotropic case was compared with the isotropic case. This showed that there is an evident difference between the isotropic and the anisotropic model at large offsets. The exact solution from the Zoeppritz's equations was also included for comparison. This proved to be very close to the approximate solution.Amplitude values from seismic gathers were included in the AVO analysis. This showed that the amplitudes from the gathers increased with incidence angle, as for the isotropic and the anisotropic model. However, the increase in amplitude was much less than for the models.From this work, the estimation of the anisotropy parameters were shown to have a large uncertainty, even after filtering. To make the estimation of delta more stable, more deviated wells to cover the whole inclination angle range, especially from 27-40 degrees, are required. Epsilon is dependent on the vertical and the horizontal P-wave velocity only, thus there should be less uncertainty in estimating this parameter.From the AVO analysis, including the amplitudes from the gathers, no conclusive statements could be established due to the fact that the amplitude values had to be scaled to fit the amplitude values with the models. The amplitudes of the gathers were scaled to the amplitude of the isotropic case at far offset, thus the result could have been altered if scaled to the anisotropic case.
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Gloria, Lopez Juan Carlos. "Integrating AVO, Seismic Inversion, and Rock Physics in Agua Fría 3D Seismic Cube." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26114.
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Ten exploratory wells have been drilled in the Agua Fría area, led by amplitude anomalies and structural highs. Five of them resulted in dry wells and the other five in gas and oil discoveries. In some of these wells, water sands respond seismically as amplitude anomalies. On the other hand, some oil and gas sands are not easily recognizable from post-stack seismic data. Bright spots are also observed in the study area.Seismic interpretation can be uncertain if no geology is related to elastic response of the subsurface rocks. The purpose of this thesis is to integrate diagenesis data from log and core data, rock physics models, AVO analysis and seismic inversion information to characterize the Agua Fría 3D seismic cube. Mechanical compaction and sorting are the main factors affecting the porosity trend in the selected wells according to the rock physics modeling. AVO class III are the main class present in the study area. However, these responses can be related to brine, oil or gas sands. Rock physics templates and seismic inversion data are useful to understand these responses and to decrease uncertainty to the analysis of these anomalies.The integration of these methodologies allow to improve the understanding of the seismic amplitude response to different geological facies present in the study area.
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Lai, Hung-Liang. "Seismic modeling of complex stratified reservoirs." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1322.
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Herrmann, Felix J., and Gilles Hennenfent. "Non-linear data continuation with redundant frames." Canadian Society of Exploration Geophysicists, 2005. http://hdl.handle.net/2429/518.
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We propose an efficient iterative data interpolation method using continuity along reflectors in seismic images via curvelet and discrete cosine transforms. The curvelet transform is a new multiscale transform that provides sparse representations for images that comprise smooth objects separated by piece-wise smooth discontinuities (e.g. seismic images). The advantage of using curvelets is that these frames are sparse for high-frequency caustic-free solutions of the wave-equation. Since we are dealing with less than ideal data (e.g. bandwidth-limited), we compliment the curvelet frames with the discrete cosine transform. The latter is motivated by the successful data continuation with the discrete Fourier transform. By choosing generic basis functions we circumvent the necessity to make parametric assumptions (e.g. through linear/parabolic Radon or demigration) regarding the shape of events in seismic data. Synthetic and real data examples demonstrate that our algorithm provides interpolated traces that accurately reproduce the wavelet shape as well as the AVO behavior along events in shot gathers.
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Alhussain, Mohammed Abdullah K. "Spherical wave AVO response of isotropic and anisotropic media : laboratory experiment versus numerical simulations /." Full text available, 2007. http://adt.curtin.edu.au/theses/available/adt-WCU20071218.160611.
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Bokhonok, Oleg. "Sísmica de reflexão rasa multicomponente: Aquisição e inversão de tempos de trânsito e amplitudes." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/14/14132/tde-06062018-155544/.
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Neste trabalho avaliou-se a potencialidade do uso da sísmica rasa de reflexão multicomponente para investigação geológica-geotécnica. Foram abordados vários aspectos relacionados à aquisição dos dados sísmicos de reflexão multicomponente, com o objetivo de entender as vantagens e limitações do método para aplicação em investigações de subsuperfície rasa. Os ensaios de campo foram realizados em duas áreas, ambas em terrenos da Bacia Sedimentar de São Paulo, em área urbana da cidade de São Paulo. Para a interpretação dos dados sísmicos multicomponente foram investigados procedimentos para a inversão não-linear dos tempos de trânsito e das amplitudes. O testes realizados orientaram a escolha da aproximação não-hiperbólica mais apropriada para calculo dos tempos de trânsito visando à análise de velocidades do pacote acima do refletor. O estudo numérico desenvolvido para a inversão das amplitudes mostrou a viabilidade da estimativa das velocidades e densidades, acima e abaixo do refletor, empregando-se as equações de Zoeppritz para as ondas refletidas PP, PSv, SvP e SvSv, antes e depois do ângulo crítico. Dada a complexidade da inversão nao-linear das amplitudes, se fez necessário elaborar uma estratégia estocástica de otimização e desenvolver uma nova abordagem para análise da função objetivo multi-dimensional, garantindo confiabilidade ao resultado da inversão não-linear. Os resultados deste trabalho mostraram o potencial da sísmica de reflexão rasa multicomponente para caracterização geológica-geotécnica, possibilitando um melhor entendimento das camadas superficiais.This thesis aims to evaluate the useful of the multicomponent seismic methods for shallow investigations, mainly its potential for the geotechnical and geological characterization of the nearsurface. Several aspects regarding the acquisition and processing data of multicomponent seismic data are discussed. They were based on data set acquired in the urban area of Sao Paulo city, Brazil. Two different areas were investigated. Both located in sedimentary terrains belonging to the Sao Paulo Sedimentary Basin. We present a non-linear travel time and seismic amplitude inversion scheme to quantitative interpretation of multicomponent seismic data. Several tests were performed to guide the choice of non-hyperbolic equation more suitable for travel time inversion aiming the velocity analysis above the reflector. A numerical experiment developed to solve the nonlinear inversion of seismic amplitudes showed the feasibility to estimate seismic interval velocities and layer densities above and below the reflector using the exact Zoeppritz equations for PP, PSv, SvP e SvSv reflected waves, before and after critical angle. Due to the apparent complexity of the nonlinear seismic amplitude inversion, it was necessary elaborate the strategy for stochastic optimization and develop a new approach to analyze the multi-dimensional objective function, with different implications for the accuracy and efficiency of the non-linear inversion. The study show the benefits of using the multicomponent seismic method for shallow geological-geotechnical characterization, improving the nearsurface understanding, once allows an integrated analyzes of a more complete record of the wave field.
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Кузьменко, П. М. "Методика спеціалізованої обробки-інтерпретації сейсмічної інформації із застосуванням AVO-аналізу та інверсії (на прикладі нафтогазопошукових задач)." Diss. of Candidate of Geological Sciences, КНУТШ, 2009.
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Nguyen, Thanh Tung. "Amplitude and AVO properties of seismic reflections from boundaries with small scale topography : a modelling study." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435809.
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Carcuz, Jerez Juan Ramon de Jesus. "An AVO method toward direct detection of lithologies combining P-P and P-S reflection data." Texas A&M University, 2003. http://hdl.handle.net/1969/38.
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Mustain, Mahmud. "The application of the shallow seismic reflection method and AVO analysis to identify the water table reflection." Thesis, University of Leicester, 2000. http://hdl.handle.net/2381/30442.
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A simple mathematical model of a sandstone aquifer has been constructed based on a local example, the Sherwood Sandstone of the East Midlands, UK. Simple seismic reflectivity calculations show that the air-water interface should theoretically produce a detectable seismic reflected wave for sandstone porosities as low as 10%. A synthetic seismic reflection dataset was constructed for a typical field survey geometry, and processed using the Promax system to produce a stacked section. The final section clearly shows the water table reflector. A field dataset from a subsequent survey has also been processed using the same sequence which also imaged a clear reflector at 30m depth. This is important evidence that the method has uses in identifying water table as a part of progress in shallow seismic reflection survey. The methods currently employed are (1) to define the optimum field, and (2) to define the optimum processing sequence, so that water table reflection can be imaged in a variety of geological situations. The application of Amplitude versus Offset (AVO) analysis to CMP gathers from the field data shows a characteristic increase of amplitude with increasing angle of incidence for super-critical reflection. In this way the water table reflector is clearly identified with the amplitude increasing by 30% over the range of incident angle from 28° to 34°. AVO analysis has also been applied to other field data that has a similar geological setting, but with a lithological reflector over the same super-critical angle. The resulting AVO curve shows a decrease in amplitude of over 90% with increasing offset, clearly differentiating from the water table reflection. Both water table and lithological results closely agree with theoretical predictions.
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Silva, Evângela Patrícia Alves da. "O uso do método AVO 4D para determinação da variação de pressão e saturação em reservatório casrbonático." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265231.
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Orientadores: Rodrigo de Souza Portugal, Alexandre Campane VidalDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências
Made available in DSpace on 2018-08-21T18:03:03Z (GMT). No. of bitstreams: 1 Silva_EvangelaPatriciaAlvesda_M.pdf: 3646847 bytes, checksum: 883531af3ee1e2c002c10ccaac9c5a59 (MD5) Previous issue date: 2012
Resumo: A resposta sísmica pode variar devido a mudanças de pressão e saturação de fluidos no reservatório durante a produção. Entender o impacto dessas mudanças nas diferenças sísmicas contribui para o gerenciamento do reservatório. Todavia, os efeitos das mudanças de pressão e saturação podem produzir respostas similares ou até mesmo iguais, conduzindo a interpretações errôneas. Analisar tais efeitos em conjunto e separadamente pode evitar ambiguidades na interpretação da resposta sísmica 4D. A metodologia AVO 4D foi utilizada nesse trabalho para separar os efeitos da mudança de pressão e saturação de fluidos por meio da variação na resposta das diferenças sísmicas. O método foi aplicado em diferentes cenários de produção: i) mudança de pressão e saturação; ii) mudança de pressão; e iii) mudança de saturação. A analise dos resultados foi realizada em seções de diferenças sísmicas sintéticas geradas a partir de dados sísmicos, petrofísicos e de produção. A metodologia proposta por Landro (2001) foi aplicada com o intuito de determinar as variações de pressão e saturação de fluidos em cada cenário, por meio de calibração petrofísica das amostras de carbonato. Foi realizado ajuste teórico por meio das equações apresentadas por Landro (2001) e comparados ambos os resultados, em seções de mudança de pressão e/ou saturação de fluidos e mapas de amplitude RMS para o topo do reservatório
Abstract: The 4D seismic response may be impacted by changes in pressure and fluid saturation in the reservoir during production. Understanding these changes in seismic differences contribute to the management of the reservoir. However, the effects of pressure and saturation changes may have the same response, leading to erroneous interpretations. To analyze these effects together and separately can avoid ambiguities in the interpretation of 4D seismic response. The 4D AVO methodology used in this work was applied in order to separate the effects of changes in pressure and fluid saturation through variation in the response of seismic differences. The method was applied in different production scenarios: i) change in pressure and saturation, ii) change in pressure, and iii) change in saturation. The analysis of the results was performed on seismic differences synthetic sections generated from seismic data, petrophysical and production. The methodology proposed by Landro (2001) was applied in order to discriminate the variations of pressure and fluid saturation in each scenario, using calibration samples of carbonate petrophysics. Were adjusted by means of theoretical equations presented by Landro (2001) and compared both results in sections of pressure change and/or fluid saturation and RMS amplitude maps to the top of the reservoir
Mestrado
Reservatórios e Gestão
Mestre em Ciências e Engenharia de Petróleo
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Voutay, Olivier. "Mise au point d'attributs sismiques pour l'interprétation AVO et 4D des réservoirs pétroliers par analyse en composantes généralisée." Vandoeuvre-les-Nancy, INPL, 2003. http://www.theses.fr/2003INPL009N.
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Nous proposons d'extraire à partir de données sismiques multicubes de nouveaux attributs sismiques par des analyses en composantes généralisées, résumant les données initiales, tout en gardant un lien clair avec ces dernières et permettant de mettre en évidence toute redondance d'information. Ces nouveaux attributs sont ensuite géologiquement interprétés à l'aide de méthodes statistiques. Dans le cadre AVO, l'apport de l'information sismique avant sommation vis à vis de l'information sismique après sommation est mis en évidence, sur un cas synthétique réaliste, puis sur un cas réel. Dans le cadre 4D, sur un cas réel, la part de non reproductibilité du signal sismique en dehors du réservoir est mesurée, puis les variations du signal au cours du temps au sein du réservoir, suite à son exploitation, sont interprétées. La méthodologie développée a également été adaptée afin de définir un attribut de cohérence, mesurant une similarité locale entre plusieurs cubes sismiques 4D ou AVO.
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Espanola, Onofre S. "Acoustic impedance inversion and AVO analysis on the Pliocene shallow gas sands, Rio Bravo field, San Joaquin Basin, California." Ann Arbor, Mich. : ProQuest, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447326.
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Thesis (M.S. in Geological Sciences)--S.M.U., 2007.Title from PDF title page (viewed Nov. 19, 2009). Source: Masters Abstracts International, Volume: 46-03, page: 1444. Adviser: David D. Blackwell. Thesis embargoed by author until 2010. Includes bibliographical references.
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Montazeri, Mahboubeh. "Reprocessing of 2D Reflection Seismic Marine Data and Investigation into the AVO behavior of Cambrian Sandstones, Southern Baltic Sea, Sweden." Thesis, Uppsala universitet, Geofysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-212092.
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A seismic line from the 2007 Dalders survey, Baltic Sea, has been re-processed and used along with well data as a basis for an investigation into the AVO behavior of the Faludden Cambrian sandstone reservoir. Line OP0701-260 is located in the southern part of the Baltic Sea with an approximate length of 52 km. The study profile lies within the Baltic Syneclise which is host to a significant thickness of the Paleozoic sediments. The area has been investigated for years for petroleum exploration and production. The Middle Cambrian sandstones are the most important reservoir rocks for hydrocarbon potential and CO2 storage potential in the Basin. 2D marine seismic data were acquired by Svenska Petroleum in 2007 and processed, but the existence of strong multiples, lack of good seismic image at depth and limited frequencies within the target zone were the significant reasons for reprocessing the data. In this study the seismic data are processed using processing software, Global Claritas, to create a new processing work flow by testing different processes and parameters to improve the processing workflow for a better stacked image. The final stacked image shows improvement in the signal to noise ratio and multiple removals. The improved stacked image shows strong reflections over the Cambrian interval which gives more confidence in the geological interpretation of the data. The B-9 well, which is located 82km south of Gotland in the Baltic Sea, sampled the Middle Cambrian interval, where P-wave velocity and density logs were recorded. Based on the good correlation between the seismic profile and the synthetic log especially for the Faludden sandstone, AVO modeling was performed based on the B-9 well. The response to changes in gas saturation and porosity within the reservoir sands are investigated. Hampson Russell AVO program was used to study the amplitude variation with offset at the Faludden sandstone interface in the seismic data. The results show a strong AVO anomaly is not anticipated associated with the Faludden interface. Different synthetic models were run for different petrophysical parameters to investigate how they can affect the AVO and stacked amplitude behavior of the data.
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Góngora, Loza Rosa Elena, Nieto Yerko Ted Mendizabal, and Morris Paula Mayra Jackeline Zorrilla. "Plan de Negocio para la elaboración y exportación de Snack de palta liofilizada marca AVO-EMY al estado de Florida – Estados Unidos." Master's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/648850.
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El presente trabajo de tesis desarrolla de un Plan de Negocio para la elaboración y exportación de Snack de palta liofilizada marca AVO-EMY al estado de Florida – Estados Unidos. La justificación de este negocio está determinada por la necesidad del productor de palta de obtener un ingreso menos incierto por el volumen de frutos cosechados considerados como “descarte”, lograr vender los frutos (llamados de “descarte”) los cuales no cumplen los requisitos para su comercialización como palta fresca para exportación y que constituirán el insumo para la producción de Snack; producto que tiene una creciente demanda por los consumidores de Estados Unidos y particularmente del estado de Florida. Además, al ser actualmente el Perú el tercer exportador de palta a nivel mundial, es de esperar que el volumen no exportado va a ser también considerable; por lo que, el presente estudio busca una alternativa innovadora para darle un buen destino a los frutos no exportados en fresco. Finalmente, el presente plan de negocio está alineado con el objetivo del estado peruano que mediante el Plan Estratégico Nacional Exportador al 2025 fomenta la diversificación de la oferta exportable.
La metodología de trabajo ha sido utilizar la herramienta PESTEL para analizar el entorno donde se desarrollará el negocio, luego realizar el análisis de la demanda fijando el segmento de mercado donde se enfocarán los esfuerzos para el cual se espera un crecimiento del orden del 8%; seguida del análisis de la oferta donde se ha determinado las zonas de producción de donde se abastecerá de palta al negocio; luego realizar el análisis FODA para fijar la estrategia a seguir y finalmente hacer uso del modelo de negocio CANVAS para decantar (luego de hacer un análisis de la competencia) en el Plan de Marketing en términos de producto (y propuesta de valor), precio, canal de distribución, promoción, personas, proceso y prueba a seguir en el horizonte de trabajo del plan de negocio que abarca desde el año 2020 hasta el año 2025. Así mismo se define la estructura de las operaciones y recursos humanos.
Mediante la evaluación económica-financiera al presente plan de negocio se ha determinado que tiene valores muy atractivos mostrando un VAN de USD 3,240.67 recuperando la inversión en 3.6 años y una TIR de 18%.This thesis develops a business plan for the preparation and export of AVO-EMY, a brand of a freeze-dried avocado snack, to the state of Florida, United States. The rationale for this business is determined by the avocado producers’ need to sell the fruit (called “de descarte”) that does not meet the requirements for fresh export and that are the input for production of snacks, which have a growing consumer demand in the United States, particularly in the state of Florida. Also, since Peru is currently the third largest avocado exporter worldwide, it is expected that the produce not being exported will also reach a considerable quantity. The present study, thus, seeks an innovative alternative to give a good destination to fruit not exported fresh. Finally, this business plan is aligned with the objective of the Peruvian government which promotes the diversification of the exportable supply as stated in the Plan Estratégico Nacional Exportador al 2025 (National Strategic Export Plan for 2025). The work methodology integrated the PESTEL tool to analyze the environment where the business will be developed, then carry out the analysis of the demand, setting the market segment where the efforts will be focused, which expects a growth of the order of 8%; followed by the analysis of the offer where it has been determined the production areas where the business will be supplied from avocado; then perform the SWOT analysis to set the strategy to follow and finally make use of the CANVAS business model to decant (after doing a competitive analysis) in the Marketing Plan in terms of product (and value proposition), price, distribution channel, promotion, people, process and test to follow in the work horizon of the business plan that covers from 2020 to 2025. Likewise, the structure of operations and human resources is defined. This business plan has determined that it has attractive values showing a NPV of USD 3,240.67 and an IRR of 18%.
Tesis
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Hennenfent, Gilles, and Felix J. Herrmann. "Sparseness-constrained data continuation with frames: Applications to missing traces and aliased signals in 2/3-D." Society of Exploration Geophysicists, 2005. http://hdl.handle.net/2429/524.
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We present a robust iterative sparseness-constrained interpolation algorithm using 2/3D curvelet frames and Fourier-like transforms that exploits continuity along reflectors in seismic data. By choosing generic transforms, we circumvent the necessity to make parametric assumptions (e.g. through linear/parabolic Radon or demigration) regarding the shape of events in seismic data. Simulation and real data examples for data with moderately sized gaps demonstrate that our algorithm provides interpolated traces that accurately reproduce the wavelet shape as well as the AVO behavior. Our method also shows good results for de-aliasing judged by the behavior of the (f-k)-spectrum before and after regularization.
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Murchek, Jacob T. "Pre-Stack Seismic Inversion and Amplitude Variation with Offset (AVO) Attributes as Hydrocarbon Indicators in Carbonate Rocks: A Case Study from the Illinois Basin." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1620214269732212.
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Vidal, Sandrine. "Méthodologie d'interprétation des paramètres réservoir à partir des mesures du monitoring sismique, intégrant l'aspect géomécanique." Paris 6, 2002. http://www.theses.fr/2002PA066369.
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Yang, Can. "Time-lapse Analysis of Borehole and Surface Seismic Data, and Reservoir Characterization of the Ketzin CO2 Storage Site, Germany." Doctoral thesis, Uppsala universitet, Geofysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-163013.
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The CO2SINK (and CO2MAN) project is the first onshore CO2 storage project in Europe. The research site is located near the town of Ketzin, close to Potsdam in Germany. Injection started in June 2008, with a planned injection target of 100,000 tonnes of CO2. In February 2011, around 45, 000 tons of CO2 had been injected into the saline aquifer at an approximate depth of 630 m. This thesis focuses on time-lapse analysis of borehole seismic data, surface seismic data and reservoir characterization at the Ketzin site. Baseline Moving Source Profiling (MSP) data were acquired in the borehole Ketzin 202/2007 (OW2), along seven lines in 2007. The zero-offset Vertical Seismic Profile (VSP) data were acquired in the same borehole. The main objective of the VSP and MSP survey was to generate high-resolution seismic images around the borehole. After modeling and data processing, the sandy layers within the Stuttgart Formation can potentially be imaged in the VSP and MSP data whereas reflections from these layers are not as clearly observed in the 3D surface seismic data. 2D and pseudo-3D time-lapse seismic surveys were conducted at the Ketzin site. Interpretation of 2D baseline and repeat stacks shows that no CO2 leakage related time lapse signature is observable where the 2D lines allow monitoring of the reservoir. This is consistent with the time-lapse results of the 3D surveys showing an increase in reflection amplitude just centered around the injection well. The results from the pseudo-3D surveys are also consistent with the 3D seismic time-lapse studies and show that the sparse pseudo-3D geometry can be used to qualitatively map the CO2 in the reservoir with significantly less effect than the full 3D surveying. The 2nd pseudo-3D repeat survey indicates preferential migration of the CO2 to the west. There are no indications of migration into the caprock on either of the repeat surveys. Amplitude Versus Offset (AVO) analysis was performed on both 2D and 3D repeat surveys. A Class 3 AVO anomaly is clearly observed on the 3D repeat data and matches the synthetic modeling well. No AVO anomaly was observed on the 2D repeat data, which was anticipated, but the result shows signs of a pressure response at the reservoir level in the data. Reflection coefficients were calculated using surface seismic data (3D and pseudo-3D) at the site. Pre-injection calculations agree well with calculations from logging data. Post-injection calculations are in general agreement with the seismic modeling, but generally show higher amplitudes than those expected. The full 3D data show a better image of the reflection coefficients before and after injection than the pseudo-3D data and can potentially be used to make quantitative calculations of CO2 volumes. The pseudo-3D data only provide qualitative information.
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Arnold, Laura Melissa. "A grammar of Ambel : an Austronesian language of Raja Ampat, west New Guinea." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31120.
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This thesis is a descriptive grammar of Ambel [wgo], an endangered Austronesian (South Halmahera-West New Guinea) language. Ambel is spoken by approximately 1600 people on Waigeo, the largest island in the Raja Ampat archipelago (West Papua province, Indonesia). This grammar is based on naturalistic and elicited data, collected by the author from native speakers of Ambel. Ambel is a head-marking language, with basic SV/AVO constituent order. There are 14 native consonant phonemes and five vowel phonemes. Ambel has a tone system, in which /H/ syllables contrast with toneless syllables. Neither stress nor vowel length are contrastive. In verbal clauses, the subject of the clause is marked on the verb. This system makes a four-way number distinction (singular, dual, paucal, and plural), an animacy distinction in the third person, and a clusivity distinction in the non-singular first person. The Ambel noun phrase is mainly head-initial. There are five distinct morphosyntactic possessive constructions, the choice of which is primarily determined by a lexical specification on the possessed noun. Some nouns (including most body parts and some kin terms) are possessed in one of three constructions in which the person, number, and animacy of the possessor is marked directly on the possessed noun, while most other nouns are possessed in one of two constructions in which the possessor is marked on a prenominal possessive classifier. Within the clause, all negation particles and most aspect and mode particles are clause-final. There is no passive construction. Ambel has a rich system of spatial deixis, in which six different classes of deictic words (such as demonstratives, deictic prepositions, and deictic nouns) are derived from one of four demonstrative roots or 28 directional stems. Verb serialisation is used to express, among other things, purposive motion and changes of state. This thesis is the first major description and documentation of the Ambel language. As such, it will be of considerable interest to typologists and historical linguists, as well as others interested in the languages, cultures, and history of New Guinea. All of the data on which this grammar is based have been archived with both the Endangered Languages Archive, and the Center for Endangered Languages Documentation at Universitas Papua in Manokwari. The data will thus be available to future generations, including the Ambel community themselves.
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Mocnik, Arianna. "Processing and analysis of seismic reflection data for hydrocarbon exploration in the plio-quaternary marine sediments." Doctoral thesis, Università degli studi di Trieste, 2012. http://hdl.handle.net/10077/7763.
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2010/2011RIASSUNTO Durante i tre anni di Dottorato di Ricerca sono state studiate ed applicate delle specifiche tecniche di analisi del segnale sismico a riflessione mirate alla identificazione di livelli di idrocarburi all’interno di sedimenti marini Plio-Quaternari. Particolare attenzione è stata inoltre dedicata alla correlazione tra questi reservoir di idrocarburi e le strutture geologiche profonde che ne possono aver favorito l’accumulo. Le metodologie utilizzate sono costituite da: 1) metodi diretti, chiamati Direct Hydrocarbon Indicators, che si basano sull’osservazione delle caratteristiche acustiche di un riflettore legato a gas; 2) metodo AVO-Amplitude Variation with Offset, che si basa sull’analisi delle variazioni delle ampiezze di riflessione in funzione dell’offset, fortemente dipendente dalla presenza di idrocarburi; 3) calcolo degli attributi sismici, grazie al quale è possibile estrarre dall'onda sismica informazioni supplementari non direttamente evidenziate nei profili sismici standard osservabili dal dato originale, che contribuiscono a verificare la presenza di gas. E’ questo il caso analizzato nel Canale d’Otranto: lungo il profilo sismico MS-29 si sono riscontrate evidenze di possibili accumuli di idrocarburi all’interno della sequenza Plio-Quaternaria; gli attributi sismici sono stati applicati al bright spot osservato, sia in fase pre-stack che in fase post-stack; il metodo è risultato fondamentale per individuare le caratteristiche di ampiezza, fase e frequenza che caratterizzano un riflettore legato a idrocarburi. L’analisi AVO, ha consentito di rinvigorire l’ipotesi di un livello saturo a gas. Il bright spot osservato è ubicato in corrispondenza del margine della piattaforma carbonatica Apula. Questa avrebbe costituito l’elemento strutturale all'origine della deformazione dei sedimenti in una blanda anticlinale: in essa sarebbero stati intrappolati gli idrocarburi grazie allo sviluppo di fenomeni di compattazione differenziata tra i sedimenti di copertura di bacino e di piattaforma. Anche in Adriatico Centrale l’analisi di un possibile livello a gas lungo il profilo sismico ADRIA-95 ha fatto supporre l’esistenza di orizzonti saturi a gas all’interno della serie sabbiosa-argillosa Plio Quaternaria. In questo caso è stato effettuato l’analisi del bright spot mediante attributi sismici e AVO, i quali hanno confermato l’ipotesi. Oltretutto, sul dato sismico è stato eseguito il re-processing mirato alla definizione delle unità sedimentarie che caratterizzano la sequenza Post-Messiniana dell’area attraversata dal profilo. Sulla base dei risultati ottenuti è stato proposto l’utilizzo degli attributi per il miglior riconoscimento delle geometrie degli strati, da cui si è potuta affinare l’interpretazione dell’assetto geologico. Si è osservato nel dettaglio che l’evidenza di gas risulta collocata in corrispondenza di strati deformati da spinte profonde legate a domi salini triassici. Oltre a questi casi di studio, sono state effettuate delle analisi di possibili livelli saturi in gas riconosciuti lungo profili sismici ubicati nel Bacino Mediterraneo, in particolare nell'offshore della Sardegna Occidentale, nel Canale di Sicilia e nel Bacino Levantino. AVO e attributi sismici sono serviti a validare l’ipotesi di presenza di idrocarburi nei sedimenti Plio-Quaternari, valutando le correlazioni ai diversi contesti geologici in cui si sono impostati. L’effetto delle procedure è stata anche testata al caso specifico dei gas-idrati, con l’obiettivo di definire se un riflettore individuato lungo un profilo sismico della Penisola Antartica, potesse essere un bottom simulating reflector (BSR); questo rappresenta la tipica manifestazione sismica di gas idrato. Le procedure di AVO sono risultate efficaci anche in presenza di idrocarburi che si trovano in specifiche condizioni di temperatura, pressione e composizione. Le medesime procedure di analisi del segnale sismico sono state quindi applicate a dati che furono acquisiti con diverse sorgenti, modalità di registrazione e geometrie di acquisizione, in funzione dei diversi target da raggiungere. Grazie a ciò è stato possibile fare un confronto tra le varie risposte del metodo a questi “parametri" e giudicare le condizioni del dato originale che consentono di ottenere i risultati più soddisfacenti. L'insieme delle analisi effettuate conferma l'utilità di un approccio sempre più avanzato di analisi AVO e di Attributi Istantanei via via più complessi. Suggerisce inoltre l'opportunità di correlare la presenza di idrocarburi agli elementi geologici presenti, riconoscibili attraverso una accurata interpretazione del dato sismico.
ABSTRACT During the three years of the PhD course specific techniques of analysis of seismic reflection data have been studied and applied, aimed at identifying the hydrocarbon saturated levels within Plio-Quaternary marine sediments. Particular attention was also devoted to the correlation between these hydrocarbon reservoirs and some deep geological structures that have favored their accumulation. The used techniques consist of: 1) direct methods, called Direct Hydrocarbon Indicators, which are based on observation of the acoustic characteristics of a gas-related reflector; 2) AVO Amplitude Variation with Offset method, which is based on the analysis of amplitude variations as a function of the offset, strongly influenced by the presence of hydrocarbons; 3) estimation of seismic attributes, from which additional information, not directly evidenced in standard seismic data, can be extracted from the reflected wave, thus contributing to verify gas presence. A first case study has been analyzed in the Otranto Channel: evidences of possible hydrocarbon accumulations along the seismic profile MS-29 have been shown within the Plio-Quaternary sequence. Seismic attributes have been applied to the observed bright spots in both pre-stack and post-stack data; the method has resulted essential to identify the characteristics of amplitude, phase and frequency parameters, that usually contribute to define an hydrocarbon related reflector. AVO analysis has allowed to strengthen the hypothesis of a gas filled layer. The studied bright spots is located over the margin of the Apulia Carbonate platform. This would represent the structural feature at the origin of the sediments deformation in a gentle anticline: here, the hydrocarbons would be trapped due to the development of differential compaction phenomena between the sediments covering the basin and the platform. A possible gas saturated level identified along the seismic profile ADRIA-95 in the Central Adriatic suggested the existence of another reservoir within the Plio-Quaternary sediments. In this case study, the analysis of the bright spots has been achieved with application of seismic attributes and AVO, which have confirmed the hypothesis. Furthermore, re-processing of the seismic data was performed, aimed at the definition of the sedimentary units that characterize the post-Messinian sequence of the area. Based on the obtained results, the attributes analysis were also applied to the improvement of definition of the strata geometries: this allowed the refining of the interpretation. It has been observed, in detail, that the evidence of gas is placed in correspondence of deformed layers by pressures derived from deep Triassic salt domes. In addition to these case studies, some other analysis have been performed after the recognition of possible gas saturated horizons along seismic profiles located in the Mediterranean Basin, especially offshore of West Sardinia, Sicily Channel and in the Levantine Basin. AVO and seismic attributes have been used to validate the hypothesis of the presence of hydrocarbons in Pliocene-Quaternary sediments, also considering the correlations to the different geological contexts in which they are set. Finally, the effect of these procedures was also tested for gas-hydrates, with the aim of defining if a reflector observed along a seismic profile of the Antarctic Peninsula, could be a bottom simulating reflector (BSR), that represents the typical seismic manifestation of gas hydrate. The procedures for AVO are found to be effective even in the typical conditions of temperature, pressure and composition related to the BSRs. The same procedures of seismic signal analysis have been applied to data that were acquired with different sources, recording mode and acquisition geometries, depending on the different target to be reached. Thanks to that, the comparison among the different responses of the methods to these "parameters" has been possible, evaluating the conditions of the original data that could produce the most satisfactory results. All the applied methods confirm the utility of a more and more advanced approach for analysis of AVO and instantaneous attributes increasingly complex. It also suggests the opportunity to correlate the presence of hydrocarbons presence with the geological elements, identified through a rigorous seismic data interpretation.
XXIV Ciclo
1982
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Butterfield, Andrei. "Characterization of a Utica Shale Reflector Package Using Well Log Data and Amplitude Variation with Offset Analysis." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401462908.
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Egreteau, Alexandre. "Etude des variations de l'amplitude de la réflectivité du sous-sol après imagerie sismique en profondeur." Phd thesis, École Nationale Supérieure des Mines de Paris, 2005. http://pastel.archives-ouvertes.fr/pastel-00001811.
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En exploration pétrolière, la technique d'imagerie la plus couramment utilisée reste l'imagerie par sismique réflexion. Elle permet d'obtenir une première représentation des structures géologiques mais aussi une estimation du coefficient de réflexion des interfaces du sous-sol. Les variations de ce coefficient dépendent des paramètres pétrophysiques des milieux situés de part et d'autre de la discontinuité donnant naissance à la réflexion (densité et vitesses des ondes de propagation et de cisaillement). Une analyse de ces variations permet ainsi d'évaluer les paramètres élastiques qui sont des données indispensables et complémentaires à l'interprétation des réservoirs. Les traitements classiques consistent à étudier ces variations directement sur des données enregistrées en fonction du déport et du temps de propagation. L'analyse s'effectue par inversion d'une approximation linéaire des équations de Zoeppritz régissant les variations théoriques de l'amplitude. Nous proposons ici d'étudier les variations de l'amplitude après la phase d'imagerie, directement dans le domaine profondeur. Pour réaliser cette analyse, nous proposons un traitement spécifique après l'imagerie et avant l'analyse de l'amplitude pour corriger les impacts liés à la qualité du modèle de vitesse, à l'interférence des ondelettes entre deux réflexions proches et à l'étirement de l'ondelette. Ce traitement a aussi permis l'obtention d'un squelette du sous-sol conduisant à une première interprétation en profondeur des réflecteurs majeurs.
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Vieira, Marco Ivo Coimbra Fino Oliveira. "A pessoa com AVC, promoção do autocuidado nas AVD." Master's thesis, [s.n.], 2013. http://hdl.handle.net/10400.26/15731.
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Mestrado , Enfermagem de Reabilitação, 2013, Escola Superior de Enfermagem de LisboaO aumento da esperança de vida, a diminuição da mortalidade e o decorrente aumento do envelhecimento da população portuguesa traduz-se no aumento do número de pessoas com Acidente Vascular Cerebral (AVC), sendo atualmente em Portugal a principal causa de morte e de incapacidade tendo as suas sequelas grande impacto na dinâmica de vida da pessoa, confrontando-se esta com um súbito défice no autocuidado na realização das Atividades de Vida Diária (AVD). Tornando-se cada vez mais premente uma resposta eficaz por parte dos profissionais de saúde, onde se insere a intervenção especializada do enfermeiro de reabilitação. Por todo o impacto que esta patologia tem na sociedade atual e na minha práxis, esta problemática constituiu um foco de interesse e motivação. Sendo a hemiplegia ou hemiparesia a alteração mais manifesta do AVC, traduzindo-se num compromisso no autocuidado das AVD, das quais se destacam a higiene e vestuário, defini como objetivo central a desenvolver no estágio “promover o autocuidado da pessoa com AVC nas atividades de vida diária de higiene e vestuário”. Constituiu-se como fundamental a compreensão das principais dificuldades enfrentadas no internamento pela pessoa com AVC, de entre as quais as que se prendem com a realização das referidas AVD. Esta identificação das principais condicionantes para o autocuidado, permitem ao enfermeiro de reabilitação através de um processo educativo, dinâmico, continuo e progressivo, no qual se destaca a centralidade do utente nas decisões, a adequação dos cuidados ao contexto domiciliário da pessoa, a individualidade dos mesmos, o estudo da inclusão de possíveis produtos de apoio e o envolvimento precoce da família no processo de cuidados visando um planeamento de alta atempado, promover o autocuidado da pessoa. Tendo como principal objetivo da sua recuperação funcional, a reintegração na família, comunidade e sociedade, tendo as suas intervenções especializadas um papel essencial na limitação do impacto da incapacidade da pessoa com AVC.
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Tamatoro, Johng-Ay. "Approche stochastique de l'analyse du « residual moveout » pour la quantification de l'incertitude dans l'imagerie sismique." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3044/document.
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Le principale objectif de l'imagerie sismique pétrolière telle qu'elle est réalisée de nos jours est de fournir une image représentative des quelques premiers kilomètres du sous-sol. Cette image permettra la localisation des structures géologiques formant les réservoirs où sont piégées les ressources en hydrocarbures. Pour pouvoir caractériser ces réservoirs et permettre la production des hydrocarbures, le géophysicien utilise la migration-profondeur qui est un outil d'imagerie sismique qui sert à convertir des données-temps enregistrées lors des campagnes d'acquisition sismique en des images-profondeur qui seront exploitées par l'ingénieur-réservoir avec l'aide de l'interprète sismique et du géologue. Lors de la migration profondeur, les évènements sismiques (réflecteurs,…) sont replacés à leurs positions spatiales correctes. Une migration-profondeur pertinente requiert une évaluation précise modèle de vitesse. La précision du modèle de vitesse utilisé pour une migration est jugée au travers l'alignement horizontal des évènements présents sur les Common Image Gather (CIG). Les évènements non horizontaux (Residual Move Out) présents sur les CIG sont dus au ratio du modèle de vitesse de migration par la vitesse effective du milieu. L'analyse du Residual Move Out (RMO) a pour but d'évaluer ce ratio pour juger de la pertinence du modèle de vitesse et permettre sa mise à jour. Les CIG qui servent de données pour l'analyse du RMO sont solutions de problèmes inverses mal posés, et sont corrompues par du bruit. Une analyse de l'incertitude s'avère nécessaire pour améliorer l'évaluation des résultats obtenus. Le manque d'outils d'analyse de l'incertitude dans l'analyse du RMO en fait sa faiblesse. L'analyse et la quantification de l'incertitude pourrait aider à la prise de décisions qui auront des impacts socio-économiques importantes. Ce travail de thèse a pour but de contribuer à l'analyse et à la quantification de l'incertitude dans l'analyse des paramètres calculés pendant le traitement des données sismiques et particulièrement dans l'analyse du RMO. Pour atteindre ces objectifs plusieurs étapes ont été nécessaires. Elles sont entre autres :- L’appropriation des différents concepts géophysiques nécessaires à la compréhension du problème (organisation des données de sismique réflexion, outils mathématiques et méthodologiques utilisés);- Présentations des méthodes et outils pour l'analyse classique du RMO;- Interprétation statistique de l’analyse classique;- Proposition d’une approche stochastique;Cette approche stochastique consiste en un modèle statistique hiérarchique dont les paramètres sont :- la variance traduisant le niveau de bruit dans les données estimée par une méthode basée sur les ondelettes, - une fonction qui traduit la cohérence des amplitudes le long des évènements estimée par des méthodes de lissages de données,- le ratio qui est considéré comme une variable aléatoire et non comme un paramètre fixe inconnue comme c'est le cas dans l'approche classique de l'analyse du RMO. Il est estimé par des méthodes de simulations de Monte Carlo par Chaîne de Markov.L'approche proposée dans cette thèse permet d'obtenir autant de cartes de valeurs du paramètre qu'on le désire par le biais des quantiles. La méthodologie proposée est validée par l'application à des données synthétiques et à des données réelles. Une étude de sensibilité de l'estimation du paramètre a été réalisée. L'utilisation de l'incertitude de ce paramètre pour quantifier l'incertitude des positions spatiales des réflecteurs est présentée dans ce travail de thèseThe main goal of the seismic imaging for oil exploration and production as it is done nowadays is to provide an image of the first kilometers of the subsurface to allow the localization and an accurate estimation of hydrocarbon resources. The reservoirs where these hydrocarbons are trapped are structures which have a more or less complex geology. To characterize these reservoirs and allow the production of hydrocarbons, the geophysicist uses the depth migration which is a seismic imaging tool which serves to convert time data recorded during seismic surveys into depth images which will be exploited by the reservoir engineer with the help of the seismic interpreter and the geologist. During the depth migration, seismic events (reflectors, diffractions, faults …) are moved to their correct locations in space. Relevant depth migration requires an accurate knowledge of vertical and horizontal seismic velocity variations (velocity model). Usually the so-called Common-Image-Gathers (CIGs) serve as a tool to verify correctness of the velocity model. Often the CIGs are computed in the surface offset (distance between shot point and receiver) domain and their flatness serve as criteria of the velocity model correctness. Residual moveout (RMO) of the events on CIGs due to the ratio of migration velocity model and effective velocity model indicates incorrectness of the velocity model and is used for the velocity model updating. The post-stacked images forming the CIGs which are used as data for the RMO analysis are the results of an inverse problem and are corrupt by noises. An uncertainty analysis is necessary to improve evaluation of the results. Dealing with the uncertainty is a major issue, which supposes to help in decisions that have important social and commercial implications. The goal of this thesis is to contribute to the uncertainty analysis and its quantification in the analysis of various parameters computed during the seismic processing and particularly in RMO analysis. To reach these goals several stages were necessary. We began by appropriating the various geophysical concepts necessary for the understanding of:- the organization of the seismic data ;- the various processing ;- the various mathematical and methodological tools which are used (chapters 2 and 3). In the chapter 4, we present different tools used for the conventional RMO analysis. In the fifth one, we give a statistical interpretation of the conventional RMO analysis and we propose a stochastic approach of this analysis. This approach consists in hierarchical statistical model where the parameters are: - the variance which express the noise level in the data ;- a functional parameter which express coherency of the amplitudes along events ; - the ratio which is assume to be a random variable and not an unknown fixed parameter as it is the case in conventional approach. The adjustment of data to the model done by using smoothing methods of data, combined with the using of the wavelets for the estimation of allow to compute the posterior distribution of given the data by the empirical Bayes methods. An estimation of the parameter is obtained by using Markov Chain Monte Carlo simulations of its posterior distribution. The various quantiles of these simulations provide different estimations of . The proposed methodology is validated in the sixth chapter by its application on synthetic data and real data. A sensitivity analysis of the estimation of the parameter was done. The using of the uncertainty of this parameter to quantify the uncertainty of the spatial positions of reflectors is presented in this thesis
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Atef, Ali Hadi Mr. "ANALYSES OF URSEIS MOHO REFLECTIONS BENEATH THE PREURALIAN FOREDEEP OF THE URAL MOUNTAINS, RUSSIA." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1181569948.
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Oliveira, Catarina Andreia Ramos. "Estudo retrospectivo das crises convulsivas na fase aguda do AVC no ano de 2008." Master's thesis, Universidade da Beira Interior, 2009. http://hdl.handle.net/10400.6/1011.
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Introdução: Os Acidentes Vasculares Cerebrais são um grave problema de saúde
pública. Trata-se de uma doença súbita que tem sido reconhecida como um factor de
risco para o desenvolvimento de crises convulsivas e epilepsia secundária, identificada
como a causa mais frequente nos idosos. A maioria das convulsões ocorre nas primeiras
24h após o AVC. O objectivo do trabalho é determinar a frequência das crises nos
doentes internados com o diagnóstico de AVC agudo na U-AVC do CHCB e seu perfil.
Materiais e métodos: Estudo retrospectivo, do ano de 2008, por consulta de processos
clínicos dos doentes admitidos na U-AVC do CHCB, com o diagnóstico de AVC agudo
e que apresentaram crises após o AVC. Efectuou-se uma análise descritiva dos casos.
Resultados: Dos 257 doentes internados na U-AVC com diagnóstico confirmado de
AVC, foram presenciadas crises convulsivas em 6 doentes, 2 do sexo feminino e 4 do
sexo masculino, com uma frequência total de 2,33%. Os 6 doentes sofreram enfarte
isquémico, registando uma frequência de 2,91% relativamente a este grupo, sendo 4
deles de origem cardioembólica, um aterotrombótico e o restante de causa
indeterminada. Também 4 deles apresentaram localização cortico-subcortical e os
outros dois, subcortical. As crises apresentadas foram, na sua maioria, parciais simples,
e manifestaram-se nas primeiras 24h após o ingresso hospitalar. Exames de imagem de
controlo e EEG foram realizados em 3 dos doentes e todos eles foram tratados com
fármacos anti-epilépticos.
Discussão/conclusões: A frequência de convulsões pós AVC apresentada pelos doentes
admitidos na U-AVC está de acordo com alguns estudos, mas não com a maioria, que
sugerem a ocorrência de uma frequência superior, assim como o facto das crises estarem
descritas apenas em doentes que sofreram AVC isquémico, já que a maior parte dos
dados sugere que estas ocorrem mais frequentemente após AVCs hemorrágicos. Em
relação à localização, os enfartes afectaram tanto a zona cortical quanto a subcortical na
sua maioria, e tiveram como origem mais comum, a cardioembólica, o que está de
acordo com a literatura. Relativamente às crises convulsivas, estas manifestaram-se
mais por crises parciais simples, tendo sido tratadas com um FAE.Introduction: The stroke is a common public health problem. It has been recognized as a risk factor for developing seizures and secondary epilepsy, being identified as the most frequent in the elderly. Most seizures occur within the first 24 hours after stroke onset. The main objective of the study is to determine the frequency and profile of seizures in patients diagnosed of acute stroke admitted to the stroke unit of the Centro Hospitalar Cova da Beira (CHCB). Patients and methods: Retrospective study during 2008, reviewing clinical records of patients admitted to the stroke unit of the CHCB, with diagnosis of acute stroke and who had seizures after stroke. A descriptive study was done. Results: Two hundred and fifty seven patients were admitted to the stroke unit with a confirmed diagnosis of stroke. Seizures ocurred in 6 patients (2.33%), 2 females and 4 males. All these patients suffered an ischemic stroke (2.91% for this group), 4 diagnosed with cardioembolic infarction, 1 with atherothrombotic infarction and 1 with undetermined stroke. Function neuroimaging studies showed cortico-subcortical infarcts in 4 patients and subcortical infarcts in the others. Near all crises were partial and were observed during the first 24h after admission. Control imaging and electroencephalogram studies were available in 3 patients and all were treated with antiepileptic drugs. Discussion / Conclusions: The frequency of seizures related to stroke found in this series is similar with previous studies. However, others authors reported a higher frequency of seizures and a higher occurrence of them in patients with hemorrhagic stroke. Regarding the location, strokes affected both cortical and subcortical areas and the main etiology was cardioembolic stroke, as previously reported. Simple partial seizures were the most common type and all were controlled with just one anti-epileptic drug.
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Teodósio, Amanda da Conceição. "Reprodutibilidade do teste de Atividade de Vida Diária AVD-Glittre em indivíduos hemiparéticos decorrente de Acidente Vascular Encefálico (AVE)." Universidade Nove de Julho, 2016. http://bibliotecatede.uninove.br/handle/tede/1899.
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The stroke can cause several sequels compromising the neuromuscular, cardiorespiratory system and consequently the performance of the functional activities. For this, an evaluation tool is needed that incorporates the capacity and the functional performance of these individuals. The ADL Glittre test proposes this objective, being already validated in individuals with COPD, but not yet applied in the population with neurological alterations. Objective: To analyze the reproducibility of the ADL Glittre test in hemiparetic individuals due to stroke. METHODS: Patient profiles were plotted for gender, age, anthropometric data, side and site of injury, motor impairment (Fugl Meyer), Mental State (Mini Mental) and Functional Mobility Scale (FMS). The ADL Glittre test was performed with the upper limb not affected, its main outcome being the completion time. For reproducibility, the subject was submitted to four evaluative moments, two intra-rater evaluations and two inter-rater evaluations, adopted randomly. Variables were normalized by the Shapiro-Wilk test, reliability by means of the Intra-Class Correlation Coefficient (ICC), the Intra and Interim Concordance by means of Standard Error of Measure (EPM) and Minimum Changeable Detection (MMD). Results: There was a significant difference in the intra-rater evaluations (1 and 2), but the differences were smaller than the MMD (1.27 and 1.14 seconds). There was no significance in the outcome of the test in the inter-rater evaluations (p = 0.20). Conclusion: The Glittre AVD is reproducible for the hemiparetic population, which I completed in approximately five minutes. Due to the learning effect it is necessary to apply the test and retest.
O AVE pode ocasionar diversas sequelas comprometendo o sistema neuromuscular, cardiorrespiratório e consequentemente o desempenho das atividades funcionais. Para isso, faz-se necessária uma ferramenta de avaliação que incorpore a capacidade e o desempenho funcional desses indivíduos. O teste AVD Glittre propõe esse objetivo, sendo já validado em indivíduos com DPOC, porém ainda não aplicado na população com alterações neurológicas. Objetivo: Analisar a reprodutibilidade do teste de AVD Glittre em indivíduos hemiparéticos decorrente de AVE. Métodos: Os perfis dos pacientes foram traçados avaliando-se sexo, idade, dados antropométricos, lado e local da lesão, comprometimento motor (Fugl Meyer), Estado Mental (Mini mental) e Escala de Mobilidade Funcional (FMS). O teste AVD Glittre foi realizado com o membro superior não acometido, sendo seu desfecho principal o tempo de conclusão. Para a reprodutibilidade o indivíduo foi submetido a quatro momentos avaliativos, duas avaliações intra-avaliadores e duas avaliações inter avaliadores, adotadas de forma aleatorizada. A variáveis foram normalizadas pelo teste Shapiro- Wilk, a confiabilidade por meio do Coeficiente de Correlação Intra classe (CCI), a Concordância Intra e Inter avaliadores por meio do Erro Padrão de Medida (EPM) e pela Mínima Mudança Detectável (MMD). Resultados: Houve diferença significante nas avaliações intra-avaliadores (1 e 2) porém, as diferença foram menores que a MMD (1,27 e 1,14 segundos). Não houve significância no desfecho do teste nas avaliações inter-avaliadores (p=0,20). Conclusão: O AVD Glittre mostra-se reprodutível para a população hemiparética que o concluí aproximadamente em cinco minutos. Devido efeito aprendizado se faz necessário aplicação do teste e reteste.
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Francisco, Luiz Roberto. "Resposta reprodutiva de psitacídeos neotropiais em cativeiro à retirada de ovos e filhotes." reponame:Repositório Institucional da UFPR, 2012. http://hdl.handle.net/1884/27510.
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Resumo: Foi realizado um estudo no sentido de levantar informações referentes à reprodução e manejo de psitacídeos neotropicais, em cativeiro e em vida livre. Para tanto, foram reunidas informações sobre a distribuição geral dos representantes da família e dos aspectos que afetam a conservação dos psitacídeos neotropicais. Foram discutidas ameaças como a perda do habitat natural e o tráfico de animais silvestres, que estão entre as principais responsáveis pelo declínio e extinção de psitacídeos neotropicais. Para o Brasil, detentor do maior número de espécies de psitacídeos no mundo, com um número em torno de 82 espécies, foram levantadas questões conceituais quanto à legislação referente ao manejo de fauna ex situ, sinopse da conservação e dificuldades para proteção dos Biomas Amazônia, Cerrado, Caatinga, Pantanal, Mata Atlântica e Pampas. Aspectos referentes à nutrição de psitacídeos em vida livre e o desenvolvimento de rações específicas para psitacídeos que permitiram proporcionar dietas nutricional adequadas em cativeiro foram abordados, assim como sua importâncias para manejos de indução a uma maior oviposição. Considerando o histórico e presente sobre ações de conservação de Psittacidae, que normalmente não incluem ações de manejo reprodutivo ex situ, realizou-se um estudo que buscou avaliar a resposta reprodutiva dos casais à retirada de ovos e filhotes em cativeiro, comparando com os dados de vida livre. Os trabalhos foram conduzidos em dois criadouros comerciais de psitacídeos silvestres nativos: o criadouro Recanto das Aves, situado em Colina – SP e o criadouro Asas do Brasil, situado em Novo Hamburgo – RS. Foram avaliadas as produções de 176 casais reprodutivamente ativos, de 8 espécies: Amazona aestiva (papagaio-verdadeiro), Amazona amazonica (papagaio-do-mangue), Amazona vinacea (papagaio-de-peito-roxo), Amazona festiva (papagaio-da-várzea), Ara ararauna (arara-canindé), Ara chloropterus (arara-vermelha-grande), A. macao e G. guarouba (ararajuba). Esse estudo mostrou que a retirada de ovos em cativeiro aumentou a produção de ovos nas espécies estudadas em diferentes níveis, quando comparados aos dados de vida livre, enquanto a retirada de filhotes com idade de 1 a 20 dias não se mostrou um procedimento eficiente quanto a induzir um número maior de posturas. Técnicas de manejo reprodutivo em cativeiro podem contribuir direta e indiretamente em ações de conservação. A utilização de procedimentos que levem a um aumento de produção permite que criadouros comerciais possam tornar mais acessíveis ao mercado um maior número de indivíduos criados legalmente em cativeiro, diminuindo a pressão de tráfico sobre populações de vida livre, de maneira a atender a uma demanda que historicamente tem sido atendida pelo tráfico de animais silvestres.
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Klemann, Júnior Louri. "Homogeneização biótica : composição e alterações da avifauna paranaense ao longo de 195 anos de modificações antrópicas na paisagem." reponame:Repositório Institucional da UFPR, 2016. http://hdl.handle.net/1884/44432.
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Orientador : Dr. Jean Ricardo Simões VituleTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ecologia e Conservação. Defesa: Curitiba, 09/08/2016
Inclui referências : f. 51-63;175-186
Área de concentração
Resumo: O conhecimento sobre a avifauna no sul da Floresta Atlântica vem sendo acumulado por meio da reunião de informações provenientes das mais diversas fontes. Dados disponíveis em publicações e museus e, mais recentemente, produzidos pela Ciência Cidadã (CC) contribuem para que a avifauna desta região seja uma das mais bem conhecidas do Brasil. Por meio de informações acumuladas ao longo do tempo são descritas alterações na comunidade de aves que estão levando à substituição de espécies raras e especializadas por espécies generalistas. Este processo, que leva à homogeneização biótica, tem sido acelerado pela intensa substituição dos ambientes naturais por ambientes antropogênicos. Considerando a necessidade de uma avaliação qualitativa e quantitativa sobre a composição e estrutura da avifauna no sul da Floresta Atlântica para o entendimento dos processos que levam a homogeneização biótica i) consolidamos uma lista geral atualizada das aves com ocorrência no estado do Paraná; ii) identificamos espécies extintas, invasoras, colonizadoras recentes e indicadoras de cada tipologia vegetal; iii) avaliamos o grau de conhecimento sobre a avifauna entre diferentes regiões do estado e o efeito da inclusão de dados da CC sobre este conhecimento; iv) avaliamos como a composição da avifauna variou ao longo período de tempo e como e quanto esta variação afetou a similaridade entre diferentes tipologias vegetais; e v) avaliamos o papel de espécies invasoras nativas, invasoras não-nativas, colonizadoras recentes e de espécies extintas no processo de homogeneização. Foram obtidos 149.814 registros de 766 espécies, 70.346 registros de fontes tradicionais de informação c 79.468 da ciência cidadã. Os dados da ciência cidadã apresentaram um importante papel na caracterização da avifauna paranaense, contribuindo de forma significativa para o aumento do conhecimento sobre este grupo em todas as regiões do estado. Ainda, os dados mostram de forma clara um crescente e complexo processo de homogeneização. Tal processo pode ser associado à ampliação das populações de espécies adaptadas ou tolerantes a áreas alteradas e à redução das populações de espécies florestais. Os resultados ressaltam, também, que comunidades com aparente estabilidade ou aumento local na riqueza de espécies podem mascarar mudanças em suas composições que estão levando à homogeneização biótica.
Abstract: Information on bird species composition in the southern Atlantic Forest is available from several published sources. Data from traditional publishing, from museums, and, recently, from Citizen Science (CS) contributes to the Paraná avifauna being one of the most known of Brazil. Through this information accumulated over time are described changes in the bird community that are leading to the substitution of rare and specialized species by generalist species. This process, which leads to biotic homogenization, is accelerated by the intense replacement of natural habitats by disturbed habitats. Considering the need for a qualitative and quantitative assessment of the bird communities in the south of the Atlantic Forest for the understanding of the processes that lead to biotic homogenization i) we consolidate an unified and updated list of the bird species that occurs in Paraná; ii) we identified extinct species, invasive species, recently-colonizing species and indicators species of each vegetation types that occurs in Paraná; iii) we evaluated the avifaunal knowledge level within geopolitical regions of the state, and we evaluated the effect of including CS data on the avifaunal knowledge level; iv) we evaluated how the bird communities varies over time and how this variation affected the similarity between different vegetation types; and v) we evaluate the role of native invasive species, non-native invasive species, recently-colonizing species and extinct species in the homogenization process. We have compiled data on 766 bird species, based on 70,346 individual records from traditional sources, and 79,468 from CS. The CS data had an important role in the characterization of Paraná avifauna, contributing significantly to the increase of knowledge about this group in all regions of the state. Furthermore, the data show clearly an increasingly complex process of homogenization. This process can be associated with the expansion of populations of bird species adapted or tolerant to disturbed areas and the reduction of populations of forest bird species. The results also unveil that communities with apparent stability or local increase in species richness may mask changes in their compositions that are leading to biotic homogenization
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Grose, Alexandre Venson. "O guará Eudocimus ruber (Aves : Threskiornithidae) no estuário da Baía da Babitonga, Litoral Norte de Santa Catarina : repovoamento, distribuição e biologia." reponame:Repositório Institucional da UFPR, 2016. http://hdl.handle.net/1884/45492.
Full textAbstract:
Orientador : Dr. Nei MoreiraTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa: Curitiba, 29/09/2016
Inclui referências : f. 23-24;44-46;65-68;78-80
Area de concentração: Zoologia
Resumo: O guará (Eudocimus ruber) é uma ave da família Threskiornithidae que ocupa ambientes aquáticos, no Brasil principalmente no manguezal. A espécie ocorre no Brasil, Colômbia, Venezuela, Trinidad, Suriname e Equador, porém na década de 70 sofreu um forte declínio populacional nos estados do sul e sudeste do Brasil (São Paulo, Rio de Janeiro, Paraná e Santa Catarina). No estado de Santa Catarina a espécie permaneceu próximo há 150 anos sem documentação. A partir de década de 1990 alguns indivíduos foram observados com maior frequência no litoral do estado de São Paulo, inclusive com a observação de ninhos e filhotes. Ao longo dos anos, a espécie começou a reaparecer nos estados onde anteriormente era observada, como Paraná, no ano de 2008. Em 2011 alguns indivíduos foram observados no norte de Santa Catarina, e na sequência alguns ninhos foram observados. Este estudo acompanha este processo de reaparecimento da espécie no litoral norte do Estado de Santa Catarina, ao longo de três anos consecutivos (2012 a 2014). Foram realizadas estimativas populacionais da espécie ao longo de três anos, assim como mapeamento das áreas de maior concentração da espécies no estuário da Babitonga. Também foram monitorados ninhos e filhotes, assim como coletados dados da dieta dos filhotes. Os resultados mostram um crescimento anual expressivo, de 7-10 indivíduos, para aproximadamente 600 em três anos. As porções mais internas do estuário são intensamente utilizadas, principalmente pela facilidade ao recurso alimentar. Ninhos monitorados na ilha Jarivatuba veem aumentando anualmente, contribuindo para aumento no número de indivíduos. A espécie vem reproduzindo com sucesso na região, mas depende de locais protegidos, pois a colônia reprodutiva vem ocupando cada vez áreas maiores. A presença da colônia reprodutiva na região e o crescimento no número de indivíduos traz esperança que esta espécie volte a ser comum na costa sul e sudeste do Brasil. Inclusive possa voltar a ocupar municípios mais ao sul do estado de Santa Catarina. Palavras-Chave: reaparecimento, reprodução, perspectivas.
Abstract: The scarlet ibis (Eudocimus ruber) is a bird of the family Threskiornithidae that inhabits aquatic environments, mainly mangrove areas in Brazil. The species occurs in Brazil, Colombia, Venezuela, Trinidad, Suriname and Ecuador, but in the 1970s a strong population decline were observed in southern and southeastern Brazilian coast. In Santa Catarina, the species has remained undocumented for 150 years. In 1990s decade, some individuals were observed on the coast of the State of São Paulo, including the observation of nests and offsprings. Over the last years, the species began to re-appear in locals where it was previously observed, such as the State of Paraná in 2008. In 2011, some individuals were observed in the north of Santa Catarina, incuding some nests. This study aimed to investigate this process of reappearance of the scarlet ibis in the northern coast of Santa Catarina, during three consecutive years (2012 to 2014). Population estimates over three years were performed, along with the mapping of the areas of high concentration of the species in the Babitonga estuary. In addition, nests and offsprings s were monitored and the diet of offsprings were described t. Results show an expressive annual growth, from 7-10 individuals, to approximately 600 individuals in three years. Inner areas of the estuary were extensively used, probably because of the large amount of feeding resources. Nests monitored on Jarivatuba Island increased annually, contributing to a raise in the number of individuals. The species has been reproducing successfully in the region, but it depends on protected sites, since the reproductive colony had been occupying larger areas. The presence of the reproductive colony in the region and the growth in the number of individuals brings hope that this species will once again be common on the south and southeast coast of Brazil. Keywords: return, reproduction, increase