Caracterização organofaciológica e organogeoquímica de sedimentos das Formações Muribeca e Riachuelo, Cretáceo inferior da Bacia de Sergipe-Alagoas

• Autor(a) principal: Ferreira, Daniel Antonio Peçanha de Martino
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7042
• topic: Sergipe-Alagoas Basin; Palynofacies; Organic Geochemistry; Hydrocarbon; Bacia de Sergipe-Alagoas; Palinofácies; Geoquímica Orgânica; Hidrocarbonetos; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS

The data presented in this dissertation discusses the results obtained with the organo-chemical and organopalinological integrated data, carried out in 23 core samples of shales and carbonates from the 9-PEO-12-SE well located in the southern portion of the Sergipe-Alagoas Basin, on shore portion. It was sought to characterize the particulate organic content, regarding the preservation state and thermal maturation and to evaluate the redox conditions. The results of light microscopy and fluorescence microscopy analysis indicate that the organic matter is dominated by elements of allochthonous origin, mainly represented by the phytoclasts group (opaque and non-opaque). The amorphous organic matter is present in practically the entire section in a small proportion, in a dispersed manner with few globose levels with oxidation indications, suggesting shallow sedimentation environments. In palynological terms, spores, pollen grains, algae and paleomicroplankton elements (dinoflagellate and palynoforaminifers). However, spores and pollen grains, especially those of the genus Classopollis (whose presence indicates an environment with arid to semi-arid climate at the deposition time) are the predominant groups. The presence of dinoflagellate and palynoforaminifers in the intermediate portion of the section proves the marine influence at the time of the deposition, here interpreted as a being the first marine incursions occurred at the end of Aptian. Based on the qualitative and quantitative kerogen results, it was possible to characterize two palynofacies, which differ from one another due to the absence of fluorescence; higher degree of oxidation and higher percentage values of TOC. The TOC results show values up to 1.65%, suggesting the presence of levels with good potential for hydrocarbon generation. The pyrolysis data indicate kerogen type IV, suitable for the generation of dry gas. The Hydrogen Index (HI) present values between 0.59 and 164.85 mg HC / g TOC, showing a potential gas generator, thus corroborating with the type of kerogen diagnosed. The ICE data show that the organic matter is near to the generation window in agreement with the Tmax data that show with values close to 432°C