Seismo-Stratigraphic Study of the Plio-Pleistocene Deposits of the Central Adriatic Sea (Italy) "Best of EAGE"

Lipparini, Lorenzo ¹; Tinterri, Roberto ²
(1) Medoilgas Italia S.p.A., Rome, Italy. (2) Dipartimento di Scienze della Terra, Università di Parma, Parma, Italy.

An integrated Seismo-Stratigraphic Study was carried out on a portion of the Central Adriatic Sea (Italy), offshore the Abruzzo coast, aimed to define and understand in detail the Plio-Pleistocene foredeep stratigraphic succession, the evolution of this area through this specific geological time, and the implication from E&P perspective. The study, based on good quality 3D data, wells and regional 2D seismic lines, is the result of an integrated 3D interpretation effort, that can be described as a “classical” seismo-stratigraphic study, the main steps being: a) Seismic sequence identification; b) Definition of the regional stratigraphic framework; c) Seismo-depositional elements identification, description and interpretation (through a classic use of amplitude and its basic derivate attributes); d) Depositional model definition and detailed 3D interpretation for each identified “element”.

In general, the Plio-Pleistocene foredeep deposits show a shoaling up trend in which the vertical evolution from deep water deposits into deltaic and nearshore strata is related to the progressive displacement of the main depocentres eastward produced by thrust propagation toward the outer margin of the foredeep basin. The stratigraphic succession of the study area, about 2 thousand meters thick, confirms the same vertical stacking pattern.

In particular, the studied interval has been subdivided in five informal stratigraphic Units on the basis of regional continuous seismic markers, showing the vertical evolution from Pliocene deep water environments (characterized by different types of meandering channel complexes and sediment drifts), to upward Pleistocene shallow water environments characterized by deltaic progradations. In particular, possibly for the first time in this area, well developed sediment drifts, related to bottom currents and associated to deep water channel complexes, were described.

In conclusion, the main results are: 1) definition of the regional seismo-stratigraphic framework for the Plio-Pleistocene deposits; 2) the recognition and description of the main depositional elements, identifying the appropriate geological model for each of them as basis for a reliable Prospect Assessment of the area and a fundamental input for the Reservoir Modelling step; 3) the description and 3D interpretation of well developed sediment drifts related to bottom currents, characterizing in particular the lower deep-water Pliocene strata.

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