Transocean Ltd.  posted a first-quarter loss as the offshore oil driller logged more than $800 million in charges related to the downsizing of its fleet in response to lower crude prices. Last quarter, Transocean logged a $992 million charge to correct the value of its contract drilling business, using up its remaining goodwill. On Wednesday, the company said it was recording a $481 million impairment from its Deepwater Floater asset group and $393 million in impairments of assets classified as held for sale. In 2014, Transocean recognized a loss of $788 million from the impairment of its Deepwater Floater asset group and a loss of $227 million, or $179 million after taxes, from scrapping a number of floaters and related equipment. The Switzerland-based company, which boasts the world’s largest fleet of offshore drilling rigs, spent billions of dollars to expand its fleet right before oil prices […]