Caracterización paleoambiental y secuencial de reservorios de la Formación Mulichinco en el Yacimiento Aguada del Chivato (sector nororiental de Cuenca Neuquina, Argentina): su contribución para el desarrollo de un campo aún inmaduro

Abstract

The Aguada del Chivato field is located in the northeastern part of the Neuquén Basin. The main reservoir of this field is the Mulichinco Formation composed by sandstones, calcareous sandstones, limestones and shales deposited in continental, transitional and open-marine environments. Based on core, cutting and electrical log data a paleoenvironmental and sequence-stratigraphic analysis was done. Nine facies associations were recognized and interpreted. Key stratigraphic surfaces were identified and assigned a hierarchy level using well control and sequence-stratigraphic approach. As a result, the evolution of the unit in the field can be summarized in four stratigraphic sections, which represent different accumulation systems and progradational or retrogradational conditions. Section A represents a fluvial to delta plain system, section B represents a mixed (carbonate-siliciclastic) marginal and shallow-marine system, section C is interpreted as a deltaic system with facies representing delta plain to prodelta settings, and finally, section D reflects the instauration of an estuarine system. Additionally, petrophysical properties of more than 500 core plugs were grouped by facies associations defining reservoir-type to non-reservoir type facies. This information was then combined with the paleoenvironmental model and the sequence-stratigraphic framework. Based on these results it has been possible to build a 3-D geological model that will allow predicting the main characteristics of the different reservoirs levels and their location within the Aguada del Chivato field. Thus, the implementation of more efficient development plans can be made for this immature hydrocarbon field.