Informe Técnico

SCASSO, R.A.; CUITIÑO, J.I.

2012-10-01/2013-11-01

1-130

Modelo exploratorio

Energia-Hidrocarburos

This report compiles the published and unpublished surface and subsurface geological information referred in the literature to as the ?basement?, ?Jurassic synrift? and ?Neocomian early sag? phases of the Golfo San Jorge basin and geologically- related sourrounding areas like the Cañadón Asfalto basin, the Deseado Massif, and the Neocomian marine sediments in the Andean region or Cordillera Patagónica of Chubut and Chile (Figs. 1 and 2). This report was requested by SINOPEC Argentina Exploration and Production Inc and aims to highlight the stratigraphy in deeper parts of the Golfo San Jorge basin, where few oil wells have been drilled and seismic lines are the main available source of geological data, in order to discover new targets for oil exploration. General stratigraphical information about the Golfo San Jorge basin and the sourrounding areas is compiled in text and synthesized in cross-sections of the basin, as well as in paleogeographic and geological maps splitted by time intervals. Lithology, thickness, fauna, age, geographic distribution, location of type-locality, paleoenvironment of sedimentation and tectonic framework are described for any significant unit. Facies analysis and their paleoenvironment of accumulation, as well as their paleogeographic distribution and their relationships in time and space are also reported for epiclastic and volcaniclastic rocks. The geodynamic implication of the basin evolution and the sequence-stratigraphic framework for the sedimentary sequences are also illustrated. Sub-surface geological information from SINOPEC areas is compared and correlated with the geological information from sourrounding areas in order to find facies models for sediments in deep troughs. These successions, mainly of Jurassic and Lower Cretaceous age, have received little attention because they underlie the Chubut Group, which is the main oil system into the basin. However, Jurassic and Lower Cretaceous oil systems exist and, up to now, they have received little attention. New investigations and methodologies are proposed here to unravel the geological and thermal history of these rocks in order to find new targets for oil exploration in the Golfo San Jorge basin.