Rodríguez, Jesús1, Solange Angulo2, Manuel Delgado2
(1) PDVSA E y P, Maracaibo, Estado Zulia, Venezuela
(2) PDVSA E y P, Puerto La Cruz, Venezuela
ABSTRACT: Sedimentological Model of the Paleocene to Lower Miocene Naricual Formation, Carito Norte and Carito Oeste Oilfields, Monagas State, Eastern Venezuela
The oilfields Carito Norte and Carito Oeste are located in the Maturín sub-basin (Monagas State), where the Naricual Formation (Paleocene to Lower Miocene) is the most important reservoir rock. Core description permitted to identify twenty-one lithofacies: twelve sandy (ten hardly burrowed and two intensely burrowed); two hetherolithics, six shaley, and one carbonaceous lithofacies; as well as a paleosoil facies. The facies with better rock quality are A7/A1/A3/A81/A41, as a result of the lowest shale volume, and the highest permeability and porosity values. Based on sedimentary facies associations, ichnofacies and biostratigraphic information, a deltaic environment was interpreted, in which low deltaic plain, bay, deltaic front and fore-delta have been recognized, with their respective sedimentary deposits associated: distributary channels, tidal influenced distributary channels, mouth bars, tidal bars, interdistributary plain, fill bay and delta front. Twenty-three sedimentary units were defined. For the sedimentary units C-1/C-2/C-3/C-4/C-5/D-1/D-2 the main direction of sediment supply was southeast-northwest, while in the units E-4/E-5/F-1 a drastic direction change to the west-east was observed. This change was attributed to the effect of the collision of the Caribbean Plate with the South American Plate. The sediments supply direction and the orientation of the sedimentary deposits are key factors in both the design of fluid injection projects for secondary recovery and the monitoring of injection fronts.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.