Exxon Mobil Corp. is using its rapid buildout in Guyana as a selling point in talks with other governments looking to develop oil and gas reserves, according to Bloomberg. The company says the speed and efficiency of its offshore projects there — which lifted production from zero to nearly 1 million barrels a day in just over six years — show it can execute complex developments better than rivals. Chief Executive Officer Darren Woods calls that a “unique value proposition” for host countries. “We’re going…