Seismic Spectral Monitoring of CO2 in a Geological Reservoir

Peak frequency is a spectral seismic attribute widely used for reservoir thickness estimation and hydrocarbon detection. In this work we apply this attribute in the context of the geological storage of carbon dioxide (CO2) and analyze its reliability as a thickness estimator for the gas accumulation. To model the vertical distribution of CO2, we solve the Buckley-Leverett equation with discontinuous flux function. A matrix reflectivity algorithm then computes, in the frequency domain, the seismic reflectivity. We find that the peak frequency variability due to CO2 saturation does not alter significantly its correlation with the accumulation thickness. We then extend the applicability of the spectral attribute by examining its time-lapse response to the evolution of the injected CO2 volume within a reservoir. We find that a description of the CO2-brine contact as well as the evaluation of the reservoir’s caprock sealing capacity can be obtained from this implementation. Peak-frequency time-lapse signatures when the CO2 forms an up-going front, evolves into a growing accumulation and leaks into the caprock are identified.Fil: Gómez, Julián Luis. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Geofísica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ravazzoli, Claudia Leonor. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Geofísica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Seismic reflectivity of a carbon dioxide flux

 In the context of the geological storage of carbon dioxide (CO2), thecharacterization of the injected CO2 in a reservoir is of primeimportance for volume capacity evaluation and long-term siteperformance. In this article, we aim to characterize a CO2 accumulationin a deep layered aquifer by means of its seismic reflectivity. Formodeling the vertical distribution of CO2 saturation in the reservoir,we solve the Buckley-Leverett equation with discontinuous flux function,which describes two-phase flow in porous stratified media. To solve thisequation numerically we employ a finite-difference relaxation scheme.The scheme entails an upwinding reconstruction for the spatialderivatives and an implicit-explicit Runge-Kutta scheme for timeintegrations. Once the vertical distribution of CO2 is obtained, we usea matrix propagator algorithm to compute in the frequency domain, thegeneralized reflectivity of the reservoir due to the injected gas. Thebehavior of this reflectivity controls the amplitude of seismic wavereflections and strongly conditions the detectability of the CO2 volumein the space-time domain. The numerical approach used in this article iseasy to implement and allows to quantify the reflectivity of the carbondioxide distribution in a practical way. We show that the frequencybehavior of the reservoir reflectivity may help to interpret thevertical accumulation of CO2, which can be useful as a basis fortime-lapse geophysical monitoring.Fil: Gómez, Julián Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Geofísica Aplicada; ArgentinaFil: Ravazzoli, Claudia Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Geofísica Aplicada; Argentin

Seismic reflectivity of a carbon dioxide flux

In the context of the geological storage of carbon dioxide (CO2), thecharacterization of the injected CO2 in a reservoir is of primeimportance for volume capacity evaluation and long-term siteperformance. In this article, we aim to characterize a CO2 accumulationin a deep layered aquifer by means of its seismic reflectivity. Formodeling the vertical distribution of CO2 saturation in the reservoir,we solve the Buckley-Leverett equation with discontinuous flux function,which describes two-phase flow in porous stratified media. To solve thisequation numerically we employ a finite-difference relaxation scheme.The scheme entails an upwinding reconstruction for the spatialderivatives and an implicit-explicit Runge-Kutta scheme for timeintegrations. Once the vertical distribution of CO2 is obtained, we usea matrix propagator algorithm to compute in the frequency domain, thegeneralized reflectivity of the reservoir due to the injected gas. Thebehavior of this reflectivity controls the amplitude of seismic wavereflections and strongly conditions the detectability of the CO2 volumein the space-time domain. The numerical approach used in this article iseasy to implement and allows to quantify the reflectivity of the carbondioxide distribution in a practical way. We show that the frequencybehavior of the reservoir reflectivity may help to interpret thevertical accumulation of CO2, which can be useful as a basis fortime-lapse geophysical monitoring.Facultad de Ciencias Astronómicas y Geofísica

Seismic spectral monitoring of CO2 in a geological reservoir

Peak frequency is a spectral seismic attribute widely used for reservoir thickness estimation and hydrocarbon detection. In this work we apply this attribute in the context of the geological storage of carbon dioxide (CO2) and analyze its reliability as a thickness estimator for the gas accumulation. To model the vertical distribution of CO2, we solve the Buckley-Leverett equation with discontinuous flux function. A matrix reflectivity algorithm then computes, in the frequency domain, the seismic reflectivity. We find that the peak frequency variability due to CO2 saturation does not alter significantly its correlation with the accumulation thickness. We then extend the applicability of the spectral attribute by examining its time-lapse response to the evolution of the injected CO2 volume within a reservoir. We find that a description of the CO2-brine contact as well as the evaluation of the reservoir’s caprock sealing capacity can be obtained from this implementation. Peak-frequency time-lapse signatures when the CO2 forms an up-going front, evolves into a growing accumulation and leaks into the caprock are identified.Facultad de Ciencias Astronómicas y Geofísica

A PROBLEMÁTICA AMBIENTAL DO CARVÃO EM SANTA CATARINA: SUA EVOLUÇÃO ATÉ OS TERMOS DE AJUSTAMENTO DE CONDUTA VIGENTE ENTRE OS ANOS DE 2005 E 2010.

O carvão é uma atividade legal e participa na composição da matriz energética brasileira com aproximadamente 1,5 %. Segundo projeção do Ministério de Minas e Energia, a contribuição da energia gerada por termelétrica a carvão deve continuar, no mínimo, nos próximos 20 anos. Contudo, historicamente a mineração de carvão deixou graves impactos ambientais na região sul do Estado de Santa Catarina. Mesmo com a entrada em vigor da legislação ambiental na década de 1970, muito pouco se avançou nesse aspecto e a população sofre com os impactos negativos deixados. O principal impacto é a geração de drenagem ácida a partir da reação química da água e ar em contato com os rejeitos piritosos dispostos inadequadamente, comprometendo os rios das bacias hidrográficas da região e suas águas subterrâneas. No ano de 2005 o Ministério Público propõe Termo de Ajuste de conduta que teve duração até o ano de 2010. A partir desse termo, as carboníferas deveriam corrigir e controlar ambientalmente todas as suas atividades de mineração. Três empresas não cumpriram o disposto no termo e por isso foram fechadas. As demais foram consideradas satisfatórias e obtiveram renovação das suas Licenças Ambientais de Operação

Activismo gráfico en movimientos sociales autoconcovados : un análisis desde el movimiento UBA de pie

La sociedad red en la que actualmente estamos inmersos implica la centralidad de tecnologías de la comunicación y de la información que se sustentan en redes continuamente configuradas y reconfiguradas (Castells, 2009). En este sentido las sociedades actuales poseen la potencialidad de generar una dimensión de transformación sustentada en una serie de redes horizontales multimodales desarrolladas tanto virtualmente como en el espacio urbano. A la luz de estas circunstancias, el objetivo general de la presente investigación será analizar las particularidades del movimiento UBA de Pie y de las piezas gráficas generadas en su contexto. En este sentido se analizan las piezas tanto en el ámbito virtual como en el espacio urbano y los modos de interrelación y difusión, y se establece una tipología de agrupamiento de la gráfica relevada de acuerdo a sus particularidades. Para ello se ha procedido al rastreo en la Web de piezas asociadas al movimiento en base a la utilización de hashtags alusivos, así como también la realización de fotografías de propia autoría en las diferentes marchas y el análisis de diferentes sitios y cuentas en redes de una serie de actores implicados. En base al material se ha podido observar la necesaria interrelación entre lo virtual y lo corpóreo en movimientos autoconvocados y horizontales como el analizado, la diversidad estilística de las piezas que si bien no conforman un sistema gráfico sí aportan una identidad visual al movimiento, y la importancia de las redes sociales como canales de expresión y difusión por parte de creadores expertos y no expertos en un contexto horizontal de creación y participación.Fil: Ravazzoli, Ignacio. Universidad de Buenos Aire

Reflection characteristics of linear carbon dioxide transition layers

Seismic monitoring of underground CO2 accumulations is a subject of growing interest in applied geophysics. Due to their large impedance contrasts, attention is focused on accumulations of high CO2 saturation in most cases. However, low-saturation zones with dispersed carbon dioxide, or saturation transition layers, may have an important role inthe propagation of waves within the reservoir, giving rise to amplitude and phase changes of the seismic signals. With this motivation, we studied the reflectivity response of a simple reservoir model with a given CO2 saturation-depth profile, on a theoretical basis. We investigated the influence of the overall saturation, vertical extent, and spatial fluiddistribution of a carbon dioxide transition zone in the reflectivity of a reservoir. The parametric analysis entails the computation of the generalized P-wave reflection coefficient and its variations with ray angle (AVA) and frequency (AVF). The combined analysis of AVA and AVF can help to characterize and monitor CO2 transition layers within geological storage sites.Fil: Gómez, Julián Luis. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Geofísica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Ravazzoli, Claudia Leonor. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Geofísica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Cinemagoing as spatially contextualised cultural and social practice

Cinemagoing as a sociocultural experience and the cinema theatre as a setting where that experience takes place are naturally linked to a certain notion of space. In fact, cinemagoing is a practice in which space is not only conceived and perceived but is also constructed; space and place are social constructs, always mediated by people’s experience and sociocultural processes. Likewise, the space of the cinema theatre is not a given but is continuously produced, reconstructed and reconfigured by audiences. This article analyses the dialectic relations between the notions of space and place and the experience of cinemagoing as a spatialised social practice and a cultural experience; it also investigates the cinema theatre as a physical, symbolic and mental setting. Overall, the article offers a theoretical reflection on the multiple notions of space in relation to cinemagoin