the company started production on the P-50 oil platform in the Albacora East field at Campos Basin, which made Brazil self-sufficient in oil production. By November 2015, the company had accumulated $128 billion in debt, 84% of it denominated in foreign currencies. Operations Business areas The company operates in six business areas, listed in order of revenue: Refining, transportation and marketing – refining, logistics, transportation, trading operations, oil products and crude oil exports and imports and petrochemical investments in Brazil Exploration and production – crude oil, natural gas liquids (NGL) and natural gas exploration, development and production in Brazil Distribution – distribution of oil products, ethanol, biodiesel and natural gas to wholesalers and through the Petrobras Distribuidora S.A. retail network in Brazil Gas and power – transportation and trading of natural gas and LNG, and generation and trading of electric power, and the fertilizer business International – exploration and production of oil and gas, refining, transportation and marketing, distribution and gas and power operations outside of Brazil Biofuels – production of biodiesel and its co-products and ethanol-related activities such as equity investments, production and trading of ethanol, sugar and the excess electricity generated from sugarcane bagasse Production and reserves Petrobras controls significant oil and energy assets in 16 countries in Africa, North America, South America, Europe, and Asia. However, Brazil represented 92% of Petrobras' worldwide production in 2014 and accounted for 97% of Petrobras' worldwide reserves on 31 December 2014, when the company had of proved developed reserves and of proved undeveloped reserves in Brazil. Of these, 62.7% were located in the offshore Campos Basin. The largest growth prospect for the company is the Tupi oil field in the Santos Basin. In 2015, the company produced per day, of which 89% was petroleum and 11% was natural gas. International investments Reserves held outside of Brazil accounted for 8.4% of production in 2014. The majority of these reserves are in South America; the company has assets in Bolivia and Colombia. Petrobras owns refineries in Texas (100,000 barrels per day of throughput). The company also owns exploration blocks in the Gulf of Mexico. Refineries North Region REMAN - Refinaria Isaac Sabbá - Manaus (Amazonas) - 46 000 bpd Northeast Region RNEST - Abreu e Lima Refinery - Suape (Pernambuco) - 230.000 bpd RPCC - Potiguar Clara Refinery - Guamaré (Rio Grande do Norte) - 37 700 bpd LUBNOR - Lubrificantes e Derivados