A Review of Petroleum Plays in the Meso-Cenozoic Carbonates in Central Adriatic Sea (Italy)

Scrocca, Davide ¹; Inversi, Barbara ¹; Lipparini, Lorenzo ²
(1)Istituto di Geologia Ambientale e Geoingegneria (CNR), Rome, Italy. (2) Medoilgas Italia S.p.A., Rome, Italy.

The Central Adriatic Sea offshore, and adjacent onshore areas (Molise and Abruzzi regions), represents a well known petroleum province, where several significant hydrocarbon occurrences, discoveries and fields have been found in particular within the Meso-Cenozoic carbonatic reservoirs.

These oil occurrences are generally associated to Late Triassic-Early Liassic source rocks although the sources distribution in the subsurface is poorly constrained by the available data. As a consequence, several (sometimes conflicting) hypotheses have been proposed through time regarding the distribution of the associated petroleum systems (among many others, Mattavelli & Novelli, 1990; Anelli et al., 1996; Bertello et al., 2010).

To improve the definition of the active petroleum system/s in the study area, a re-interpretation of the available data (wells, seismic reflection data and outcrop geology), coupled with a critical revision of published models, has been carried out. In particular, a special attention has been devoted to: a) the analysis of the oil shows/occurrence areal and stratigraphic distribution and, b) the analysis of the tectonic controls on the development of the Late Triassic - Early Liassic euxinic basins.

The characteristics of known regional source rocks, from both outcrops, well data and published geochemical data (e.g., Mattavellli & Novelli 1990), indicate that at least two different, although of similar age, source rocks exist in the study area, namely: 1) the Rhaetian-Early Liassic Emma Fm in the Central Adriatic area and 2) the Late Triassic Burano Fm further south (Ombrina-Rospo Plateau and Abruzzo onshore). As a result, two different petroleum systems (Magoon & Dow, 1994) have been defined in the Central Adriatic domain: the Burano-Apulia (!) Petroleum System and the Emma-Scaglia (!) Petroleum System. According to published source rock depositional models (e.g., Zappaterra, 1994), the recognized source rocks can be related to two types of euxinic intaplatform basins characterized by a different tectonic evolution.

An updated hypothesis on the possible distribution of these source rocks will be discussed based on the review of existing models and on our interpretation of the Triassic evolution of the Central Adriatic area.

Moreover, a possible migration model that takes into account an integrated analysis of the carrier/reservoir regional distribution and faults/fractures occurrence will be presented as well.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.