GEORGETOWN (Reuters) - A consortium led by Exxon Mobil ( XOM ) is getting ready for a very active year for exploration and production in Guyana amid upgrades that expanded the capacity of some of its floating facilities and the expected arrival of a fourth vessel, the head of the U.S. oil major in Guyana said on Wednesday.

The group has requested environmental permits from Guyana's government for its Longtail project, the first that will produce non-associated gas, and to explore the Hamlet well in the southeast portion of its massive Stabroek offshore block.

Longtail is expected to add up to 250,000 barrels per day (bpd) of crude output capacity and 1 billion cubic feet per day of natural gas production, said Alistair Routledge, president of Exxon Guyana, in a press conference.