Partners at the prolific ExxonMobil-operated Stabroek Block offshore Guyana have begun production from their Liza Phase 2 development, using a second FPSO vessel called Liza Unity, ExxonMobil and Hess Corp. said separately Feb. 11. No information was immediately available on the initial volume of barrels produced. The Liza Unity, moored in water depths of around 1,650 meters, is expected to…