Shell said it started production from Mars B using its Olympus platform, which the company said was its largest deep-water platform in the Gulf of Mexico.
Olympus is floating in roughly 3,100 feet of water off the coast of Louisiana.
Shell said the entire Mars field produced an average 60,000 barrels of oil equivalent per day last year. With Olympus in place, Mars field production should reach 100,000 barrels of oil equivalent per day by 2016.
John Hollowell, executive vice president for Shell's deep water operations in the Americas, said in a statement Tuesday the Mars developments showcase Shell's ongoing commitment to deep-water activity.
"Olympus is the latest, successful start-up of our strong portfolio of deep-water projects, which we expect to generate substantial value in the coming years," he said. "Deep water will continue to be a core growth opportunity for Shell."