Sequence Stratigraphy Analysis of Carapita E Lower Miocene; North of Monagas, Venezuela

Abstract

The Carapita E sandstone is of lower Miocene age, and occurs in the maturin sub-basin within the active thrust belt of the eastern Venezuela tertiary foreland basin. This basin is a prolific hydrocarbon basin and the Carapita sandstones form an important reservoir system. This study is based on an integration of well logs and cores from 56 wells covering an area of more than 39.000 km[sup 2] the sediments were interpreted in terms of depositional environments and sequence stratigraphic patterns. The sandstone unit overlies a type I sequence boundary (25,5 m.y.) and in the central and western part of the study area it is interpreted as a lowstand systems tract, deposited within an incised valley on the shelf. Further east, the sediments were deposited in a coastal to shelf setting and the unconformable sequence boundary is interpreted to pass into a correlative conformity. These more distal shoreline sands from a shelf-perched lowstand prograding wedge which is coeval with the incised valley fill further landward they comprise coastal and nearshore deposits in the form of prograding coastal/deltaic bars and shoreline sands. This detailed sedimentological and sequence stratigraphic study has resulted in improved productivity and optimization of hydrocarbon recovery from the Carapitamore » E sands.« less