Developing a depositional model to define stratigraphic architecture in mudstones: Cretaceous Agrio Formation, Argentina

Abstract

The mixed-carbonate-siliciclastic, Cretaceous Agrio Formation has recently drawn new attention in the hydrocarbon-rich Neuquén Basin of Argentina as an emerging unconventional mudstone play. The proposed sequence stratigraphic study plans to characterize the most basinal marine setting of the Agrio Formation and source rock intervals, where previous studies have addressed southern, more proximal to shoreline, study areas. An increase in carbonate content is predicted in more distal settings with a reduction in siliciclastic content and an increase in source rock quality. A detailed sedimentological and geochemical assessment of northern outcrops will be used to establish distal depositional facies variability and depositional mechanisms. Regional changes in mineralogy in the context of facies, especially in respect to carbonate content, will be tested using X-ray diffraction (XRD). Programmed pyrolysis will be used to assess the source rock quality. With this facies analysis, a downdip depositional model will be developed to test or revise previous established updip depositional models. Prior studies have identified greater potential source rock intervals in the lower Agrio Formation from outcrop. These outcrop studies with new northern studies will be correlated into the subsurface to characterize the reservoir quality, sequence stratigraphic variability, and the reservoir’s hydrocarbon potential on the eastern fringe of the basin. In order to address the reservoir quality and storage capacity, a diagenetic study will be investigated using thin sections and scanning electron microscopy (SEM)This project will aid in addressing the Agrio Formation’s geographic spatial extent and its potential as an international hydrocarbon source rock unconventional reservoir.

AAPG Datapages/Search and Discovery Article #90351 © 2019 AAPG Foundation 2019 Grants-in-Aid Projects