Industria petroqum̕ica Petrochemical industry 2 Bituminous shale 1 California 1 Combustibles 1 Combustibles fs̤iles 1 Destilacin̤ de superficie en retorta 1 more ... Energy return from investment 1 Esquistos bituminosos 1 Estados Unidos 1 Fossil fuels 1 Fuels 1 Industria del petrl̤eo 1 Petrl̤eo de esquisto 1 Petroleum industry 1 Produccin̤ in situ 1 Production in situ 1 Retorno energťico de la inversin̤ 1 Shale oil 1 Surface distillation in retort 1 United States 1 agotamiento de petrl̤eo 1 eficiencia energťica 1 energy efficiency 1 energy ratios 1 energy return on investment 1 industria petroqum̕ica 1 oil depletion 1 oil production 1 oil refining 1 less ...