Combustibles 4 Combustibles fs̤iles 4 Fossil fuels 4 Fuels 4 Industria del petrl̤eo 4 Industria petroqum̕ica 4 Petrochemical industry Gehiago ... Petroleum industry 4 energa̕ 3 energy 3 fuentes de energa̕ 3 Environmental impact 2 Impacto ambiental 2 energy sources 2 environment 2 gas natural 2 medio ambiente 2 natural gas 2 oil 2 petrl̤eo 2 petroleum 2 Derrame de petrl̤eo 1 Drilling 1 Economa̕ industrial 1 Energa̕ 1 Energy 1 Energy sources 1 Engineering economy 1 Estados Unidos 1 Exploracin̤ 1 gutxiago ...