A debt deal is good, but until more of these are getting work, Seadrill remains risky. Image source: Seadrill. Offshore drilling contractor Seadrill Ltd. (NYSE: SDRL) operates the newest, most capable fleet of vessels operating, but it's also one of the most heavily leveraged offshore drillers, and it's the overhang of its big debt that's easily the biggest risk the company faces. On April 29, the company announced that it had reached agreement with its banking group to both give it more breathing room before nearly $3 billion of that debt comes due and amend key covenants related to all of its debt facilities.