The scope of this study covers the Cañadón Seco León area on the southern flank of the Golfo San Jorge Basin and focuses on the last 130 m to the Top of the Fm. Pozo D-129. The best productions of the Fm. P. D- 129 come from vertical wells and one horizontal well located in an area without seismic data coverage. On the other hand, the area with seismic coverage has an incipient development, so it is proposed to try to reconcile the information available from each area to generate a robust geological model for these successions of the Upper Section of the Fm. Pozo D-129. The 3D seismic data covers the region to the east and south of the main development. The studied area offer as well other relevant information as cores from some production levels and resistive well images.Mainly, amplitude attributes and well data were used to identify anomalies and geoforms. Morever, maps of thicknesses in time and seismic sections contribute to identify depositional features of clinoforms. This seismic interpretation analysis allowed to establish a depositional model of the Fm. P. D-129 in the zone with seismic coverage and it was useful as sedimentary model analog for the area with the main oil field development without seismic data. The methodological flux applied in this work come from the experience used in others flanks of the San Jorge Basin. This work points out what was useful from this methodological loop and which singularities were critical to identify potential reservoir and their areal distribution for Fm. P.D-129.