GNGTS 2019 - Atti del 38° Convegno Nazionale

GNGTS 2019 S essione 3.1 539 bright spot sited just below, but also from other minor gas evidences in the Plio-Quaternary sedimentary succession. Conclusion. The OCSS_15 geophysical survey provided new detailed information about the Otranto Channel buried structures and seafloor morphology. Processing and interpretation of this new dataset allowed us to focalize the Mesozoic Apulia carbonate platform margin and to better constrain a huge gas reservoir related to the presence of deep-sited coral mounds. From processing we obtained really good time migrated sections, applying strong multiples attenuation’s algorithms. New sections of the OCSS_15 bring a better resolution never available in the studied area at that depth. The imaging of the MS29 section has been improved also through a PSDM (Pre-Stack Depth Migration) section, using two different kinds of tomographic inversion techniques. The detailed interpretation of the bright spots shows that gas reservoir is sealed by Plio- Quaternary hemipelagic formations deposited above an erosive surface currently ascribed to a ZancleanAge. Therefore, we assessed that the gas migration could occur also in the hemipelagic sedimentary cover, escaping via several minor faults, resulting in multiple gas reservoirs in the Plio-Quaternary superficial clinoforms. This is a notable finding for the understanding of this kind of fluids migration and accumulation. Carbonate platform margins are currently a hot topic in petroleum exploration because carbonates are good “source rock” for oil and gas and platform margins - being highly fractured - allow the migration of fluids that if capped by a sedimentary impermeable cover could accumulate. Finally, we found a biunivocal correlation between deep and shallow structures, namely gas reservoirs and coral mounds. Hence, coral banks - where found below the photic zone - could be used as hydrocarbon indicator suggesting gas accumulation in the subsoil beneath them. Because the presence of these coral mounds is due to the presence of bio-constructor organisms that feed and grow thanks to natural gases coming from below. References Anstey N. A.; 1977: Direct Hydrocarbon Detection. In Seismic Interpretation: The Physical Aspects Springer, Dordrecht. pp. 306-393. Del Ben A., Forte E., Geletti R., Mocnik A., and Pipan, M.; 2011: Seismic exploration of a possible gas-reservoir in the south Apulia foreland. Bollettino di Geofisica Teorica ed Applicata, 52(4). Hovland M., and Judd A.; 1988: Seabed pockmarks and seepages: impact on geology, biology, and the marine environment. Springer. Mattavelli L., Novelli L., and Anelli L.; 1991: Occurrence of hydrocarbons in the Adriatic basin. Spec. Publ. EAPG, 1, 369-380. Verschuur D. J., Berkhout A. J., and Wapenaar, C. P. A.; 1992: Adaptive surface-related multiple elimination. Geophysics, 57(9), 1166-1177. FLUID MODELING BELOW MESSINIAN SALT DEPOSITS: IONIAN ABYSSAL PLAIN & MALTA ESCARPMENT BASE N. Bertone 1 , A. Del Ben 1 , A. Camerlenghi 2 , C. Hübscher 3 1 Dipartimento di Matematica e Geoscienze – DMG, Università di Trieste, Italy 2 Istituto Nazionale di Oceanografia e di Geofisica Sperimentale – OGS, Trieste, Italy 3 CEN - Center for Earth System Research and Sustainability, Institute of Geophysics, University of Hamburg, Hamburg, Germany Introduction. During the Mesozoic, the Mediterranean area was part of the Tethys Ocean. In the Cretaceous/Cenozoic age, the collision between Eurasian and African plates produced the Alpine-Himalayan orogenesis, leading to a closure of the previous ocean. The Ionian Basin is considered a relic of this Tethys Ocean where, during the Messinian Salinity Crisis (MSC)