With contracts canceled and debts mounting, offshore oil drillers face another shakeout

DENVER/OSLO (Reuters) - The companies that operate offshore drilling rigs for major oil producers face a second wave of bankruptcies in four years amid a historic drop in energy prices that likely will leave surviving drillers more closely tied to big oil firms.A collapse of the offshore industry will have broad impact. Drillers and their suppliers have driven innovation that has helped shale and offshore wind companies by pioneering remote monitoring and control, and last year directly..