Impact of Synsedimentary Mesozoic Tectonics on the Hydrocarbon Plays Offshore Sicily

Alberto Riva, Raffaele Di Cuia, and Mara Marian

The Sicily Offshore is an area where hydrocarbon exploration has been very intense during the last 50 years. The area presents a variable bathymetry related to some deep grabens and a complex geology due to the development of the submerged Maghrebian chain and its foredeep, coupled with co-existing extensional features. One key factor for a successful exploration in this area is the deep understanding of the complex Mesozoic tectonic history that affected the area.

The Upper Triassic –Lower Jurassic play is proved in the offshore SE Sicily, with some major discoveries, made during the ‘80s (e.g. Vega Field). The source rock is mainly represented by the Noto and Streppenosa Formations, while the reservoir is hosted in the Lower Jurassic platform carbonates. Some onshore outcrops (Rocca Busambra, Monte Kumeta, Montagna Grande) are extremely helpful to determine the uncertainties related to this play.

This play has been proved in Vega, Mila, Prezioso and Perla discoveries, but in some offshore areas it is still poorly understood, due to the scarce quality of seismic data below the Messinian evaporites.

The Lower Jurassic tectonics controls the development of the source rocks within restricted basins (Streppenosa, Marineo, etc.) and it is also controls the subsidence rates within the carbonate platform.

The Mesozoic tectonic activity is also accompanied by several volcanic episodes, mainly concentrated in the Upper Jurassic and in the Upper Cretaceous. This magmatic events are adding important uncertainties about the degree of maturation of the source rocks and are probably responsible for the dolomitization of platform carbonates in some areas.

The continuous fault movements are also responsible of possible leakages across the cap rocks (Buccheri Fm).

AAPG Search and Discovery Article #90161©2013 AAPG European Regional Conference, Barcelona, Spain, 8-10 April 2013