Aromatics: are unsaturated cyclic hydrocarbons consisting of one or more benzene rings (a six–carbon ring with three double bonds). Aromatics include benzene, toluene, mixed xylenes, p-xylene, o-xylene, ethyl benzene, monomer styrene and PTA.

Burning oil:  consisting of paraffin, petroleum and aromatic hydrocarbons, this product is used as heating and thermal power generation fuel and is one of the main constituents of jet fuel.

Crude oil : a mixture of hydrocarbons that exists in a liquid phase in natural underground reservoirs. Crude petroleum mainly consists of saturated and unsaturated aliphatic hydrocarbons and some aromatic materials. In addition to hydrogen and carbon that are the main constituents of oil, it contains nitrogen, oxygen, sulphur, nickel, sodium, vanadium and iron as well. As a result of the changes in the amount of these elements, crude oil is much diversified physically and chemically.

Fuel oil:  a residual substance obtained from    the distillation of crude oil in refineries.   Because of its heavy hydrocarbon content, this product does not burn easily. It is one of the main fuels for ships and large manufacturing establishments including power generation plants.

Gas consumer: the person who consumes        gas after subscription and operations of gas supply.

Gas customer:  the natural or legal person whose characteristics have been registered and who has been given a customer number after their submission of required documents and payment of related costs based on formal procedure for admission of natural gas applicant.

Gas extension:   the    lines   which   have    been extended     from    transmission,     feeding   and network lines into the customer's private station.

Gas injection: gas and/or water injected into oil reservoir for optimum utilization and preservation of resources.

Gas oil: obtained  from the separation of burning oil from crude petroleum, this product is used as fuel for agricultural and industrial machinery and public transport vehicles and for thermal installations.

Hydrocarbons: include propane, butane, pentane plus, pentane, pyrolysis gasoline, C4 raffinate, C6 raffinate, CFO, MTBE.

Jet fuel: is used as engines fuel for fighter      and passenger aircrafts. It is produced in different types in terms of mixture of high quality burning oil and other light oil products with some additives to prevent rusting, reduce the risk of icing, etc. In international standards, it is known as JP4 and ATK.

Liquefied gas: a  mixture of  normal  butane  and propane, the proportion of which  changes  under environmental   conditions   and   utilization  and becomes   liquid  under  a  pressure  of   100-110

Motor spirit: a mixture of isomerized and circular hydrocarbons with different concentrations, to which certain organic compounds are added  for easy burning.

Natural gas (enriched gas): gas obtained from oil and gas reservoirs, available as associated gas (such as gas extracted from Aghajari gas field), non-associated gas (such as Sarakhs and Sarkhun gas) or gas cap gas.

Sweet gas: enriched (natural) gas obtained from further refining, that is, separation of liquids and gaseous impurities from enriched gas.