Combustibles 2 Combustibles fs̤iles 2 Fossil fuels 2 Fuels 2 energa̕ 2 energy 2 energy sources 2 Gehiago ... fuentes de energa̕ 2 gas natural 2 industria del petrl̤eo industria petroqum̕ica 2 natural gas 2 oil 2 oil industry 2 petrl̤eo 2 petrochemical industry 2 petroleum 2 refinacin̤ 2 reservoirs 2 reservorios 2 wellheads operaciones 1 operations 1 pozos 1 procesos 1 processes 1 refining 1 gutxiago ...