Stratigraphic correlation and sedimentary analogs: Ballena Hill outcrops and Cañadón Vasco oil field, Southern flank of San Jorge Basin, Argentina

DI BENEDETTO, L., S.M. GEORGIEFF, G.POTAS

Cartagena de Indias, Colombia.

Simposio; Simposio Bolivariano de Hidrocarburos; 2006

The present study proposes a correlation between outcrops and subsurface data in the Southern flank of the San Jorge Basin, Argentina. Extensive exposures belong to Bajo Barreal Formation, Cretaceous, crop out in the Ballena Hill and oil wells of Cañadón Vasco field located at the foot of the Hill allow performing a precise stratigraphic correlation between them and improve the knowledge about subsurface fluvial models. The stratigraphic correlation was realized using seismic information and well data. Thus, the quantitative fluvial models proposed in a surface work were applied to subsurface deposits using fms images, dipmeters and a trace inversion study. In tun, an ignimbrite has been identified in the Ballena Hill and dated by Ar/Ar method at 91±0.49 Ma., this event is previous to the beginning of the deformation that reactivated the area and changed the sedimentary facies arrangements. The study is innovative in the San Jorge Basin since includes and correlates 2D seismic data and well data (well logs, cuttings, lateral cores, cores and images) from the oil field to a previous research and new information obtained during surface geology surveys (thickness and paleocurrents measurements, channel and fluvial belt widths). The study has enabled the reassessment of the work area (abandoned field until this study) and it has proposed its reactivation through the workover of three ancient wells to the new interest levels, which obtained positive results in hydrocarbon extraction, with very good production outcomes. These achievements allowed us to propose ten wells to be drilled in the year 2006, and the shooting of a 3D seismic data.