Avaliação estratigráfica da Sub-bacia de Juruena, Bacia dos Parecis

Abstract

The Parecis Basin is one of the largest Brazilian intracratonic basins and has the Amazonian Craton as basement. Until now, few studies have been carried out due to lack of available data. Up until the early 2000 s, the sedimentation of the basin was considered to be predominantly Paleozoic. Recently, new seismic and well data were acquired, and recent studies that analyze the adjacent areas consider that the Parecis Basin contains Proterozoic sediments. This dissertation elaborated, through the interpretation of seismic data, well correlation and the integration of these data, a depositional model for the Proterozoic age of the basin for the portion of the Juruena sub-basin that is related to the Paraguay Belt sediments. The workflow utilized was seismic interpretation, large sedimentary packages and identification and behavior of the seismic facies for each sequence in the northern and southern portions of the study area. Well correlation was used to delimit the sequences utilizing the lithologic log and the gamma ray curve patter for the wells 2-SM-0001-MT e 2-ANP-4-MT. Ultimately, the integration of the seismic and well data refined the interpretation and allowed the association of the sequences mapped to the formations of the Paraguay Belt. As such, it can be considered that the Proterozoic sedimentation of the Parecis Basin is a preserved portion of the Paraguay Belt with sediments deposited in context of the passive margin basin originating from the separation of the Rodinia supercontinent. The region suffered various orogenic processes, with the Brasiliana Orogeny being the more expressive, which originated the Paraguay Belt. This is part of the ancient basin that arose from the collision process of the Amazonian Craton with the Parana Block. The conclusion of this work was the reorganization of the formations of the Neoproterozoic section of the southern portion of the Parecis Basin, where the Juruena sub-basin is situated in the vicinity of the northern Paraguay Belt. In addition to this result, it was possible to observe from the seismic interpretation, escape gas structures, predominantly in the 0295-0010 seismic line, which is in the sub-surface region of the Teles Pires river, recognized by the gas exudations of thermogenic, biogenic and atmospheric origins