Exploitation - (depletion, production), retrieving natural wealth; recovery of petroleum and natural gas.
Ecological fuel – fuel for internal combustion engines (petrol and diesel fuel) with a minimum sulphur content. ‘’Pure fuels’’ must be unleaded and sulphur-free due to the fact that these substances harm or undermine the operation of modern engines and auxiliary devices (catalysts), which are constructed so as to lower the emission of dangerous, ‘’greenhouse’’ gases (carbon II-oxide, methane, nitrogen oxide etc.) that pollute the atmosphere as a whole and are probably the cause of global warming.
Eruption – controlled seepage of petroleum, natural gas and water through a well by well pressure; uncontrolled eruption: free seepage of fluid from underground through a well to the surface.
Eruptive rocks - (volcanic, igneous), rocks that are the result of cooling and crystallisation of magma (melt).
Ethane – gaseous hydrocarbon (C2H6) produced by the treatment of natural or refinery gas when planned to be used as feedstock for the production of ethylene.
Eterification – reaction of olefin and alcohol resulting in ether. If isobutylenes such as methanol react, then methyl isobutyl ether (MTBE) is produced, with excellent antiknock (detonator) characteristics, that is, a high octane number, which makes it an excellent petrol component.
Ethylene – unsaturated hydrocarbon (C2H4), colourless gas produced by processing ethane, propane, petrol etc.; feedstock for further petrochemical refining (plastic mass).
Exploration well/borehole – w ell of a specific construction and depth, whose purpose is to discover petroleum or natural gas reservoir (as well as geothermal water, potable water, etc.).