An assembly to recover hydrocarbon gas from a seabed comprises one or more self-propelled drilling devices that include hydrocarbon sensors and a sublimation mechanism to induce sublimation of crystallized hydrates into hydrocarbon gases. As the drilling device moves through the wellbore, hydrocarbon deposits are detected and the sublimation mechanism induces sublimation of the deposits to release hydrocarbon gases up through the formation to the seabed. A bladder is positioned atop the wellbore to capture the release hydrocarbon gas and transfer it to a surface vessel for collection.