Evaluation and Characterization of a Potential CO₂Storage Site in the South Adriatic Offshore

Abstract

-The Southern Adriatic Sea is one of the five prospective areas for CO 2 storage being evaluated under the FP7 European Sitechar project. The potential reservoir identified in the investigated area is represented by a carbonate formation (Scaglia Formation -Late Cretaceous). This paper shows the site characterization applied to one of the structures identified in the carbonate storage system of the South Adriatic offshore. The interpretation and analysis of seismic and borehole data allowed the construction of a 3D geological static model on both regional and local scales. Dynamic modeling was applied, adopting a sensitivity approach ( i.e. fault transmissivity, petrophysical properties of the caprock and reservoir, and different stress regimes). Coupled fluid flow and geomechanical simulation was applied to investigate the potential risk of leakage induced by mechanical solicitation on the faults occurring in the investigated area.Résumé -Évaluation et caractérisation d'un site de stockage potentiel de CO 2 au sud de la Mer Adriatique -Le sud de la Mer Adriatique est l'une des cinq zones potentielles pour le stockage du CO 2 évaluées dans le cadre du projet FP7 européen SiteChar. Le réservoir potentiel identifié dans la zone étudiée est constitué d'une formation de carbonate (Formation Scaglia -Crétacé supérieur). Cet article présente la caractérisation de site de stockage de CO 2 appliquée à l'une des structures identifiées dans les formations carbonatées du sud de la Mer Adriatique. L'interprétation et l'analyse des données sismiques et des données de forage ont permis la construction d'un modèle statique géologique 3D à des échelles régionale et locale. Une modélisation dynamique a été effectuée, intégrant une analyse de sensibilité (sur la transmittivité des failles, les propriétés pétro-physiques des roches couverture et réservoir, et différents régimes de contraintes). Une simulation couplée géomécanique et d'écoulement de fluide a été menée pour étudier le risque potentiel de fuite provoqué par les contraintes mécaniques sur les failles de la zone étudiée.

A Comparison Between Sea‐Bottom Gravity and Satellite Altimeter‐Derived Gravity in Coastal Environments: A Case Study of the Gulf of Manfredonia (SW Adriatic Sea)

“…South of the Gondola ridge, the gravity edges approximately correspond to the Jurassic faults as interpreted from seismic data ( D. Morelli, 2002 ). In addition, the central axis of the ridge derived from gravity well data correlates with the pre-existing seismic interpretation ( D. Morelli, 2002;Volpi et al, 2015 ). This confirms that part of the information contained in the sea-bottom and satellite-altimetry gravity represents a 3D sub-surface fault network ( Fairhead, 2016;Fedi & Florio, 2001;FitzGerald & Milligan, 2013 ).…”

“…Each of these minima is covered by more than three gravity stations, and they are not related to any local structural discontinuity as shown by seismic reflection profiles on the top of the carbonate layer, which appears to be relatively flat in this sector. Excluding the presence of localized deeper sources and/or measurement biases, these small gradient changes may be related to localized variations within the Pliocene and Pleistocene sediments ( D. Morelli, 2002;Volpi et al, 2015 ). As described in the geological setting above, at least two different sedimentary units have been recognized from the interpretation of seismic profiles ( Figure 2b ): the upper unit is composed of Plio-Quaternary siliciclastic sediments, which we assumed are less dense and less compacted than the lower Oligocene-Miocene unit composed of silico-clastic and calcareoclastic turbidites ( Volpi et al, 2015 ).…”

“…This model includes the interface between the Oligocene Quaternary sediments and the underlying carbonate platform, as per Volpi et al. (2015), in which depths were derived from a 2D inversion of multichannel seismic profiles constrained by well‐log data. The gravity effect of the seismic interface is computed using the Parker method in the FFT domain (Parker, 1973): $$${\Delta}\ g\left(x,y\right)=FF{T}^{-1}\left\{-2\pi G{\Delta}\rho {e}^{-{h}_{0}\left\vert \vec{K}\right\vert }\sum\limits _{n=1}^{\infty }\frac{{\left\vert \vec{K}\right\vert }^{n-1}}{n!$$…”

Dynamic Fluid Flow and Geomechanical Coupling to Assess the CO2Storage Integrity in Faulted Structures

“…The geological characterisation of the Southern Adriatic Sea (Volpi et al, 2015) led to three sites potentially suitable for CO 2 storage: the Grazia, Rovesti and Grifone structures (Fig. 2).…”

“…The 3D geological model is described in Volpi et al (2015). It is composed of the following geological elements (Fig.…”