bufferzones(ecosystemmanagement) continentalshelf economicaspects engineering environmentalaspects environmentalpolicy environmentalprotection evaluation forageoffshore gasengineering gaznaturel governmentpolicy lawandlegislation lawofthesea mesures mining offshoregasindustry offshoreoilandgasleases offshoreoilindustry offshoreoilwelldrilling oilwelldrilling petroleumengineering petroleuminsubmergedlands puits pétrole safetymeasures sécurité technology unitedstates