ANÁLISIS INTEGRADO DE LA TRANSICIÓN ENTRE LAS FORMACIONES VACA MUERTA Y QUINTUCO Y SU IMPLICANCIA PALEOAMBIENTAL EN EL PERFIL DE PUERTA CURACO, CUENCA NEUQUINA

CAPELLI, IGNACIO; SCASSO, R.A

Mendoza

Congreso; 10º Congreso de Exploración y Desarrollo de Hidrocarburos Simposio de Recursos No Convencionales: Hacia una Nueva Convención; 2018

Instituto Argentino del Petróleo

The Vaca Muerta-Quintuco system in the Puerta Curaco section (northern Neuquén Basin), consistsof a 716 m thick shallowing-upward cycle deposited from early Tithonian to early Valanginian. TheVaca Muerta Formation represents a world-class unconventional play since 2010, nevertheless,there is not agreement on the stratigraphic position of the top of Vaca Muerta Formation yet. Thiscontribution provides a stratigraphic analysis of the vertical transition (35 m) between the VacaMuerta and the Quintuco Formations, including sedimentological, geochemical and mineralogicalanalysis. The transition interval is characterized by: 1) an increase of calcareous shales compared tothe underlying unit 2) a broad and smooth peak of Gamma-Ray associated to high values of K andTh 3) an increase in clay minerals (illite, chlorite and mixed-layered illite/smectite) when compared tothe underlying unit 4) relative low values of Mo and U, suggesting a decrease in the organic contentand 5) complete dolomitization of the limestones beds. These observations indicate an importantchange in the paleoenvironmental conditions, suggesting an increase in detrital sedimentation andthe emplacement of a mixed siliciclastic-carbonate system. These changes are associated to apronounced sea-level fall, based on the configuration of regional seismic data. The high-resolutioninsights derived from this study in Puerta Curaco section may be used to gain further knowledgein the subsurface sections where the lack of core in the key stratigraphic sections hampers suchinferences.