Análises palinofaciológicas e palinológicas da Formação Tremembé na Fazenda Santa Fé (Bacia de Taubaté) aplicadas à caracterização do potencial gerador de hidrocarbonetos

Abstract

We applied the techniques of organic petrography and palynology on the testimony from well TMB-01-SP located in the central portion of the Taubate Basin. Visual analysis of 41 organopalynologiacal and palynological slides allowed to individualize three palynofacies and place the section in terms of time. From the results of quantitative analysis of organic content, there was a predominance of amorphous organic matter of lacustrine origin and the presence of algae Botryococcus braunii and Pediastrum sp. Subordinate, there was also the presence of pollen grains, spores, phytoclasts and cuticles. Due to the predominance of amorphous organic matter and lacustrine algaes with minor contributions of material from higher plants, it was possible to classify the kerogen as types I and III. The amorphous organic matter had a moderate to high fluorescence in most of the section (palynofacies 1 and 3) indicating a prevailing reducing environment. The results of spore color index (ECI) were between 1,5 and 2,5 indicating immature zone of hydrocarbon generation. From the palynological analisys, it was possible to observe a rich and diverse association with 49 species identified, including pollen grains, spores, algae and fungi. The results allowed to correlate the studied section with the palynozone Parvisaccites? sp. (Regali et al., 1974), which corresponds to Oligocene. Among the diagnostic palynomorphs of age and depositional environment were identified: Catinipollis geiseltalensis, Cicatricosisporites dorogensis, Dacrydiumites florinii, Echitriletes muelleri, Ephedripites tertiarius, Perisyncolporites pokornyi, Podocarpidites marwickii, Polypodiaceiosporites potoniei, Psilatricolporites operculatus, Quadraplanus sp., Ulmodeipites krempii e Verrucatosporites usmensis. The sediments studied were deposited in a shallow lacustrine paleoenvironment under reducing conditions over almost the entire section.