GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 3.1 569 GAS EMISSIONS IN THE NORTHERN ADRIATIC SEA G.M. Ferrante 1 , F. Donda 2 , V. Volpi 2 , U. Tinivella 2 1 Università degli Studi di Trieste, Italy 2 Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Trieste, Italy Introduction. The Northern Adriatic sea is characterized by a widespread occurence of gas in the subsurface, testified by the presence of gas-related seabed and sub-seabed features, and by gas seeps, mostly composed by CH4 (Donda et al. , 2015). However, the origin of the gas and its migration paths through the sedimentary column are still not well constrained. Several gas fields have been discovered and exploited off the Venice Lagoon during the 60’s, while no hydrocarbon-related activities are currently underway in the study area. In 2009 and 2014 OGS carried out two seismic surveys in the Gulf of Venice collecting more than 1200 km of multichannel 2D seismic lines, CHIRP sub-bottom profiles and swath morpho-bathymetric data (Fig.1). Fig. 1 - Location map of the geophysical data collected in the framework of the STENAP and GANDI projects. The two seismic lines processed for this work are reported in red. Yellow dots indicate the location of analyzed hydrocarbon exploration boreholes. The inset at the lower right corner represents a sketch of the regional structural setting (modified after Donda et al. , 2015). These data were acquired with the main aim of constraining the relationship between gas emissions and the regional geological setting of the study area and to characterize the gas- charged fluids occurring within the sedimentary succession. The objective of this work is the quantification of gas content along two perpendicular profiles whithin the Plio-Quaternary sedimentary succession, through the petrophysical characterization of the sediments using well- log seismic attribute correlation. The proper characterization of the gas occurrence in the study area has direct implications formdifferent point of views: 1.The innovative andmultidisciplinary approach used could be applied in other areas characterized by gas-charged fluids in similar geological settings; 2.The comprehensive evaluation of the gas occurrence and its migration throughout the sedimentary succession will help in constraining the role of tectonic features