Subsidence induced by offshore gas production in the northern adriatic sea

In the decades between early '70s and '90s, ENI discovered 15 gas fields in the Northern Adriatic Sea, offshore the historical city of Venice. Notwithstanding the social and economic value of these resources, in 1995 the Italian Government issued a decree stopping all projects of offshore development in the Northern Adriatic Sea, in order to better evaluate the environmental impact on land. To this regard, it is important to remind that in Italy have been recorded significant phenomena of land subsidence connected with natural gas production. This paper is aimed to briefly recall the well-studied cases of subsidence in the Po River Delta region and in the town of Ravenna, highlighting in both cases the different extent of the phenomenon, the surveys and the monitoring systems adopted, and eventually the actions undertaken to limit subsidence. Finally, the paper outlines some provisional suggestions about the possibility to produce gas from Northern Adriatic offshore fields, without compromising the coastal altimetry, and so the integrity of the historical cities of Venice and Chioggia and their complex lagoon ecosystems. In general, it is necessary to establish a wide and proactive cooperation among Oil Companies, National and Regional Authorities and Research Institutes, in order to manage development projects in the most favorable way for the whole Community.