Papers by Abel Carrasquilla
12th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 15–18 August 2011, 2011
Magnetotelluric responses of soundings under the equatorial electrojet in Brazil have been estima... more Magnetotelluric responses of soundings under the equatorial electrojet in Brazil have been estimated for four distinct locations at the north and south of the Magnetic Equator. It has been observed that the effect of the concentrated ionospheric currents (electrojet) in equatorial zones is added to the electromagnetic data and act as source. The difference between daytime and nighttime data indicates that source boosted by the electrojet, mainly observed at daytime, provides better estimation of the earth response functions even for lower frequencies (<0.01Hz).
Proceedings, 2018
Summary Carbonates can exhibit a complex mineralogy and complicated pore system, and petrophysica... more Summary Carbonates can exhibit a complex mineralogy and complicated pore system, and petrophysical properties of carbonate reservoir rocks can vary significantly because of the reactive nature of minerals during the diagenesis. In this way, carbonate outcrop rocks can be employed as analogous to reservoir modelling and understanding of the pore system properties as porosity and permeability. This study employs carbonate outcrop samples of limestone, dolomitic limestone, and dolostone from Sultanate of Oman, inserted in two distinct geological contexts at Huqf and Dhofar. X-ray micro-tomography images were correlated with mineralogical and petrophysical measurements to characterize the pore system properties of interest as porosity and permeability at different lithology. Mineralogy was affected by the dolomitization that may have caused changes in texture and pore system. However, density analysis showed that the dolomite occurrence cannot be considered as an isolated parameter for permeability evaluation. The computed pore size diameter, pore throat diameter, and medium pore chord were applied for pore system characterization and have a direct relationship with permeability, expressing best permeability for simple texture structure samples. PoA and DOMsize results allowed a good analysis of the pore complexities and effects on permeability, suggesting a great potential for rock evaluation.
8th International Congress of the Brazilian Geophysical Society, 2003
7th International Congress of the Brazilian Geophysical Society, 2001
Brazilian Journal of Geophysics
The permeability estimate, using geophysical well logs, is an important and difficult task in a r... more The permeability estimate, using geophysical well logs, is an important and difficult task in a reservoir characterization, which is usually done with empirical models or statistical regression. Thus, logs were used to achieve this goal in two wells of a carbonate reservoir in Campos Basin, together with geological information and laboratory measurements on rock samples. The test Well A10 was zoned in electrofacies and models were built for each one. Next, the hydraulic flow units were defined and correlated to the logs and to the electrofacies. The same was done in a blind test in Well A3. The Principal Component Analysis, Cluster and Discriminant techniques, Multiple Linear Regression, Alternate Conditional Expectation and Hydraulic Flow Unit were used. The quality of the estimates was calculated using the Mean Absolute Error and the Coefficient of Determination. At Well A10, the Hydraulic Flow Unit was the most promising approach. The Alternate Conditional Expectation, without zoning, was the closest to experimental laboratory data in Well A3. These results indicate that all methods are feasible in inferring permeability, however, an inadequate classification of zones can lead to erroneous estimates.
81st EAGE Conference and Exhibition 2019, 2019
9th International Congress of the Brazilian Geophysical Society & EXPOGEF, Salvador, Bahia, Brazil, 11-14 September 2005, 2005
9th International Congress of the Brazilian Geophysical Society & EXPOGEF, Salvador, Bahia, Brazil, 11-14 September 2005, 2005
1st International Congress of the Brazilian Geophysical Society, 1989
6th International Congress of the Brazilian Geophysical Society, 1999
Um conjunto de metodos geoeletromagneticos foi empregado na parte sudeste da bacia do Parnaiba pa... more Um conjunto de metodos geoeletromagneticos foi empregado na parte sudeste da bacia do Parnaiba para a investigacao de aquiferos profundos. Diversas sondagens eletrica vertical (SEV), eletromagnetica transiente (TEM) e magnetotelurica (MT) foram realizadas ao longo de um perfil de 180 km, que atravessa importantes feicoes estruturais e se estende ate a borda cristalina sudeste da bacia. Os dados geoeletromagneticos foram invertidos ‘conjuntamente’ utilizando esquema de inversao 1-D, apresentando a distribuicao da resistividade eletrica em profundidade para cada sondagem. O uso integrado de TEM/MT permitiu corrigir os dados MT de “static shift” e melhor definir as estruturas rasas e profundas. Resultados da inversao 2-D dos dados MT permitiu mapear a distribuicao lateral dos aquiferos e identificar as principais feicoes estruturais que influenciam o regime hidrodinâmico da bacia, apresentando boa concordância com a interpretacao dos dados aeromagneticos. Os resultados obtidos evidenciam a importância da utilizacao de metodos geoeletromagneticos integrados como meio de se obter informacao fundamental para estudos hidrogeologicos em bacias sedimentares.
SEG Technical Program Expanded Abstracts 2020, 2020
8th International Congress of the Brazilian Geophysical Society, 2003
Proceedings of the 5 Simpósio Brasileiro de Geofísica, 2012
Proceedings of the 4 Simpósio Brasileiro de Geofísica, 2010
Seu conteúdo foi revisado pelo Comitê Técnico do IV SimBGf, mas não necessariamente representa a ... more Seu conteúdo foi revisado pelo Comitê Técnico do IV SimBGf, mas não necessariamente representa a opinião da SBGf ou de seus associados. É proibida a reprodução total ou parcial deste material para propósitos comerciais sem prévia autorização da SBGf.
15th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 31 July-3 August 2017, 2017
SEG Technical Program Expanded Abstracts 2014, 2014
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef, 2019
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Uma perfilagem geofísica de poço consiste na medição de vários parâmetros físicos. Um destes parâ... more Uma perfilagem geofísica de poço consiste na medição de vários parâmetros físicos. Um destes parâmetros é a resistividade, a qual pode ser utilizada no registro das características elétricas das rochas, obtendo um valor volumétrico ligado à matriz da rocha e aos fluidos presentes nos poros das rochas, informações que permitem definir as propriedades do reservatório. Objetivos O presente trabalho tem como objetivo elaborar um programa que simule um perfil laterolog em um meio tridimensional, utilizando a técnica numérica da Equação Integral. Nesse trabalho será utilizada a técnica numérica da equação integral, a qual tem se mostrado mais eficiente em comparação com a formulação das equações diferenciais, isso deve-se ao fato de que no método da equação integral são modelados somente as heterogeneidades do meio geológico. Além disso, quando o método experimental ou condição de observação não pode ser expresso em termos de uma condição inicial ou de fronteira, então o problema é frequentemente modelado como uma equação integral, pois estas são satisfeitas automaticamente. Os resultados que serão obtidos no presente trabalho, serão comparados com os resultados obtidos por Cozzolino (2004), apresentados na figura abaixo.
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Papers by Abel Carrasquilla