Bolivia has been enjoying the benefits of a natural gas export boom, but the good times could well be coming to an end. At present, natural gas accounts for nearly half of Bolivian export revenue by value, driven by rising production from three major natural gas fields in southeastern Bolivia's Tarija department. La Paz's annual income from natural gas exports rose from $2.8 billion to $6 billion between 2010 and 2014, as natural gas prices remained heavily influenced by the price of fuel oil in Brazil and Argentina. Fortunately for landlocked Bolivia, both countries have been ideal long-term consumers of natural gas. In the case of Argentina, declining natural gas production, a domestic regulatory environment that dissuades investment by foreign energy firms and a lengthy economic crisis have created an energy production deficit filled partly by Bolivian natural gas exports.