Utilize the input text as a context reference, choose the right relationship between 'Petrobras' and 'gas' from the options.
Options: product/material produced, distribution format, distributed by, chief executive officer

But now, after about $250 billion of investment and the discovery of some of the world's largest offshore oil and gas resources, Petrobras is producing 2.8 million boepd, 20 percent less than its estimate for 2012 output.
product/material produced