Paraná Basin: petroleum potential in the depocenter area

Abstract

Since the end of last century, several isolated research campaigns have been conducted in Southern Brazil's Paraná Basin by different firms and government agencies. So far 107 wells have been drilled, some 22 000 km of seismic lines acquired, and other geological and geophysical studies conducted, with modest results in terms of oil and gas discoveries and also in terms of assessing the basin's overall petroleum potential. Results from some specific wells are very significant, however, as these are related to stratigraphic locations. The most notemorthy of these are sub-comercial occurrences of oil or gas at Três Pinheiros (SC), Matos Costa (SC), Cuiabá Paulista (SP), and Chapéu do Sol (PR), all found in the depocenter area of the Paraná Basin . Located in the far west of the Brazilian part of this basin and limited operationally by the Brazilian border with Paraguay and Argentina, the depocenter area constitutes a vast region extremely deficient in exploratory data. However, information obtained from the few wells drilled there, together with recent seismic data, permits an optimistic estimate to be made of the area's petroleum potential. In regional terms, the depocenter area displays all the requisites necessary for hidrocarbon accumulation: various pelitic sections of potencial source rock in the Silurian, Devonian, and Permo-Carboniferous sequences; good reservoirs, principally in the Rio Bonito Formation; and good seismic indications of structures associated with large basement lineaments, reactivated over geologic time by the compressional tectonics of the western margin of the South American plate.