Caracterización Estática de la Formación Centenario en el Yacimiento Estación Fernández Oro, provincia de Río Negro, Argentina.

Abstract

This study addresses the static characterization of the Centenario Formation in the Estación Fernández Oro (EFO) field, located in the Neuquén Basin, Argentina. The main objective is to evaluate its potential as a reservoir for the reinjection of flowback wáter, a key practice for the controlled and safe disposal of this fluid in compliance with a current environmental regulation. The methodology combines sedimentological, stratigraphic, and structural analyses, integrating well logs, cutting descriptions, and petrophysical calculations. Data from 60 wells were processed using tNavigator software, allowing for the development of structural, isopach, and isoproperty models. These models facilitated the identification of litofacies distribution and the estimation of key properties such as effective porosity and clay volumen. The results show that the sandstones of the Lower Centenario Member exhibit favorable characteristics as reinjection reservoirs, highlighted by their quartzose composition, médium grain size, and good petrophysical properties. In contrast, the sum of the clayey levels of the Upper Centenario Member acts as a natural hydraulic seal, ensuring the containment of injected fluids and preventing their migration of upper levels. This interpretation is supported by the integration of well log data and cutting descriptions, which allowed for the delineation of the horizons of both members of the formation. The structural análisis revealed a differential inclinaton of the member tops relative to the base, atributted to post-depositional tectonic events. This configuration, together with the presence of hydraulic seals, ensures the system’s stability and the retention of injected fluis in the subsurface. This research provides a comprehensive evaluation of the Centenario Formation as a potential unit for flowback wáter reinjection. The combination of a robust methodology with an analysis of the litofacies properties enabled the identification of suitable áreas for the location of reinjection Wells, contributing to the efficient and environmentally safe management of flowback water.