U.S. Sen. David Vitter, a Louisiana Republican, said he hopes it leads to "much bigger final action with BP, the main culprit in this horrible disaster."
BP spokesman Geoff Morrell said the deal "underscores what every official investigation has found: that the Deepwater Horizon accident resulted from multiple causes, involving multiple parties."
"Transocean is finally starting, more than two-and-a-half years after the accident, to do its part for the Gulf Coast," he said in a statement.
Transocean previously announced it had reserved $2 billion for paying claims related to the Deepwater Horizon disaster.
Transocean also said in a September regulatory filing that it had rejected settlement offers last year from BP and a group of attorneys for Gulf Coast residents and businesses who blame the spill for economic damages. Those claims are still pending.
Last month, U.S. District Judge Carl Barbier in New Orleans gave final approval to a class-action-settlement agreement between BP and a team of private plaintiffs' attorneys. BP estimates it will pay about $7.8 billion to resolve these claims, but the settlement isn't capped.
Barbier also is set to preside over a trial designed to identify the causes of BP's deadly well blowout and assign percentages of fault to the companies involved. The first phase of the trial is scheduled to start Feb. 25.
Alabama Attorney General Luther Strange said the Transocean settlement is "one more step in holding the responsible parties accountable for the catastrophic environmental and economic damage inflicted on Alabama and the entire Gulf Coast."
"There is more work to be done, and Alabama stands ready for trial in February," he said.
But Alabama Gov. Robert Bentley said he was disappointed in the size of the settlement.
"We don't believe this is adequate compensation for the people of Alabama," he said. "We look forward to holding BP and others accountable at trial."
The Deepwater Horizon was drilling in water a mile deep about 50 miles southeast of the Louisiana coast when it exploded on the night of April 20, 2010.
The Justice Department says Transocean crew members on the rig, acting at the direction of BP supervisors, failed to fully investigate clear signs that the well was not secure and that oil and gas were flowing into the well.
Associated Press writers Pete Yost in Washington, Melinda Deslatte in Baton Rouge, La., and Bob Johnson in Montgomery, Ala., contributed to this report.