Forbes | Will Big Oil Discovery In Guyana Boost Growth At Exxon Mobil And Hess? Forbes Exxon Mobil and Hess estimate that a deeper reservoir directly below their previously discovered Liza Field on the Stabroek block off the coast of Guyana could contain another 100 million to 150 million barrels of oil equivalent. (Photo by Samir ... Exxon Finds More Oil Offshore Guyana ExxonMobil Announces New Oil Discoveries Offshore Guyana |