INVESTIGADORES
RAINOLDI Ana Laura
congresos y reuniones científicas
Título:
Montmorillonite as indicator of intense bleaching of the Cretaceous Portezuelo redbeds in the Barda González area, the Neuquén Basin, Argentina
Autor/es:
PONS, JOSEFINA; RAINOLDI, ANA LAURA; ROBIN VALENTIN; FRANCHINI, MARTA; BEAUFORT DANIEL; PATRIER PATRICIA
Lugar:
Río de Janeiro
Reunión:
Conferencia; XV International Clay Conference; 2013
Institución organizadora:
AIpea, Associacao Brasileira de Geologos de Petroeleo y Grupo Brasileriro de Argilas
Resumen:
The Barda Gonzalez region located in the Dorsal de Huincul structure of the Neuquén Basin, is characterized by the occurrence of oil fields and regional structures at depth and the presence of solid hydrocarbons impregnating the outcrops of the Cretaceous (LateTuroniano -Early Coniaciano) fluvial rocks of the Portezuelo Formation (Neuquén Group: Cenomanian-Campanian). Some of the structures of the Huincul system were reactivated during the Tertiary Andean orogeny, and acted as vertical channels connecting the reservoir fluids with the subhorizontal paleochannel of the Portezuelo Formation. The circulation of these fluids in the clastic rocks is documented by the presence of bitumen associated with calcite, pyrite and clay minerals rims. This presentation establishes the relationship between the diagenetic processes, the migration of hydrocarbons and their implication in the clay mineral precipitation. The Portezuelo Formation in the Dorsal de Huincul region only could reach shallow burial conditions considering that it was covered by a sedimentary column of ~ 700 m thick. These deposits form a fining-upward sequence composed of a medium-grained sandstones and subordinate conglomerates layers (0.4 to 2.5 m thick each) rich in intraclasts of claystone and siltstone, interbedded with beds (