(New throughout, adds detail from conference)

By Sheila Dang

HOUSTON, March 25 (Reuters) - Exxon Mobil ( XOM ) has a

team in Venezuela this week evaluating the country'soil and gas

resources and infrastructure, upstream head Dan Ammann said

Wednesday at the CERAWeek by S&P Global conference in Houston.

In January, Exxon CEO Darren Woods called Venezuela

"uninvestable" without durable protections for new investment,

comments that landed him in hot water with U.S. President Donald

Trump. The top U.S. oil producer exited Venezuela in 2007 after

its assets were expropriated.

"What we're looking to assess is the state of the resource

that's there, but more importantly, what's the state of the

infrastructure on the ground?" Ammann said.

There are short-term actions that can be taken to

incrementally increase oil production, he said, but fully

rebuilding Venezuela's oil industry would likely take a long

time and cost hundreds of billions of dollars.

Venezuela's oil output has dwindled due to underinvestment

in the OPEC member nation that once produced 3 million barrels

per day.