South Atlantic-focused oil explorer Rockhopper reports that samples from its recent discovery on the Sea Lion prospect, off the Falkland Islands, have been confirmed as medium grade crude.Rockhopper took the sample from the Sea Lion 14/10-2 oil discovery well in the North Falkland Basin and tested them under reservoir conditions. "These positive results, when combined with our knowledge of reservoir quality from logging data, give us further comfort that a flow test of the Sea Lion well will confirm a mobile crude oil," Sam Moody, Rockhopper's managing director, commented. "The wax content is typical for a lacustrine sourced crude oil and significantly lower than many other producing oilfields worldwide. Furthermore the viscosity, gas oil ratio, FVF and sulphur are all better than we anticipated," he added.Last month, Rockhopper upgraded its estimate of recoverable reserves at the Sea Lion prospect in the North Falkland Basin from 170m barrels to 242m barrels, adding it has "significant upside potential".