A chief economist with the world\'s third-largest oil producer British Petroleum (BP) on Tuesday said he had no concerns over global oil supply in the foreseeable future. \"Our problem does not lie under the earth,\" BP Group chief economist Christof Ruehl was quoted as saying by the Austrian Press Agency APA. Despite considerable increases in costs over the recent years, BP expected its annual output to increase by 18 percent over the next 20 years to 103 million barrels per day, Ruehl said. He said problems in oil availability would more likely result from politics such as access restrictions.