Chemostratigraphy Applied to the Upper Cretaceous of the Southern Santos Basin, Well Case Study - Paraná, Brazil

Authors: Lucas Cazelli Vasconcelos (presenter), Rene Rodrigues, Rio de Janeiro State University (UERJ)

This study presents the organic geochemistry data obtained from the Upper Cretaceous interval in a well located on the southern Santos offshore Basin, Paraná, Brazil. The objectives of applying Total Organic Carbon Content, Pyrolysis, Stable Carbon Isotopes and Biomarkers analyses are to show their effectiveness as an alternative for high frequency correlation of the studied interval in the Santos Basin as well as analyze the characteristics of the organic matter present in relation to source-rock parameters, depositional environment and source of organic matter input.

As shown by isopach maps (Assine et al., 2008), the well is located within the depocenter of the basin for the interested time-interval preserving a wide thick shale interval that can be mapped through seismic and geochemistry studies. It was possible to suggest the division of this interval in chemostratigraphic unities related to the sedimentary succession preestablished for the basin. The organic content of the shales indicates moderate to very good generation potential (fig. 1), with facies A and B at the beginning of the hydrocarbon generation window. The organic geochemistry data shows T/R cycles patterns as well as anoxic events related to Cenomanian and Turonian OEA 2 - backed up by isotopic data presented - also registered regionally and around the world. Therefore, it is shown the chemostratigraphic parameters as a possibly new regional sequence stratigraphic and correlation tool.

Bio:

Lucas Cazelli Vasconcelos, Rio de Janeiro State University

Lucas is a geologist from Rio de Janeiro State University (UERJ).

Currently, he is a Master’s student at UERJ’s post-graduate program with accepted project entitled “Organic Geochemestry and high resolution Chemostratigraphy: Upper Cretaceous of the Southern Santos Basin, Brasil”. He received a research grant for Geology Graduation Student at UERJ’s Stratigraphy and Paleontology Departament (2018/2019).

Lucas is a member of SBG (Brazilian Geological Society).