Crude Oil
Asia-Pacific Economic Cooperation (APEC)

European Commission - Eurostat
Crude oil is a mineral oil of natural origin comprising a mixture of hydrocarbons and associated impurities, such as sulphur. It exists in the liquid phase under normal surface temperature and pressure and its physical characteristics (density, viscosity, etc.) are highly variable.

This category includes field or lease condensate recovered from associated and non-associated gas where it is commingled with the commercial crude oil stream.

International Energy Agency (IEA)
Crude oil is a mineral oil of natural origin comprising a mixture of hydrocarbons and associated impurities, such as sulphur. It exists in the liquid phase under normal surface temperature and pressure and its physical characteristics (density, viscosity, etc.) are highly variable.

This category includes field or lease condensate recovered from associated and non-associated gas where it is commingled with the commercial crude oil stream.

International Energy Forum Secretariat (IEFS)
Crude oil is the most important oil from which petroleum products are manufactured, but several other feedstock oils are also used to make oil products. There is a wide range of petroleum products manufactured from crude oil. Many are for specific purposes, for example, motor gasoline or lubricants; others are for general heat-raising needs, such as gas oil or fuel oil.

The quality of crude oil depends to a great extent on its density and sulphur content. The crude oils are classified as light, medium and heavy according to their density. Crude oils with high sulphur content (at least 2.5% sulphur) are sour, while sweet crudes have often less than 0.5% sulphur content.

Latin American Energy Organization (OLADE)
This is a complex mixture of hydrocarbons of different molecular weight, in which there is a generally small fraction of compounds containing sulfur and nitrogen. The composition of the oil is variable and can be divided into three classes, according to the distillation residues, as paraffins, asphalts or a combination of both.

Oil is used as a raw material in refineries for processing and obtaining its derivatives. In specific cases it is also used for final consumption in given industrial activities.

Organisation of Petroleum Exporting Countries (OPEC)
Crude oil comprises crude oil, natural gas liquids, refinery feedstocks and additives as well as other hydrocarbons.

United Nations Economic Commission for Europe (UNECE)
Crude oil is a mineral oil of natural origin comprising a mixture of hydrocarbons and associated impurities, such as sulphur. It exists in the liquid phase under normal surface temperature and pressure and its physical characteristics (density, viscosity, etc.) are highly variable.

This category includes field or lease condensate recovered from associated and non-associated gas where it is commingled with the commercial crude oil stream.

UNSD Energy Statistics Section
Crude oil - a mineral oil consisting of a mixture of hydrocarbons of natural origin, yellow to black in color, of variable density and viscosity. Data in this category also includes lease or field condensate (separator liquids) which is recovered from gaseous hydrocarbons in lease separation facilities, as well as synthetic crude oil, mineral oils extracted from bituminous minerals such as shales and bituminous sand, and oils from coal liquefaction.

Extra heavy crude oils – have densities greater than 1000 kg/m3 (API gravities less than 10o API).

Heavy crude oils – have densities from 934 to 1000 kg/m3 (API gravities from 20o to 10o) inclusive. These densities (API gravities) are referenced to 15.6o C and atmospheric pressure.

World Energy Council (WEC)
Crude oil is a naturally occurring mixture consisting predominantly of hydrocarbons that exists in liquid phase in natural underground reservoirs and is recoverable as liquids at typical atmospheric conditions of pressure and temperature. Crude oil has a viscosity no greater than 10 000 mPa.s (centipoises) at original reservoir conditions; oils of greater viscosity are included in Natural Bitumen and Extra-Heavy Oil.

Conventional oil: oil with an API gravity of greater than 20° (density below 0.934 g/cm3). API gravity is the inverse of density and is computed as (141.5/sp g)-131.5 where sp g is the specific gravity of oil at 60 degrees Fahrenheit.

Extra-heavy oil: extra-heavy oil is commonly defined as oil having a gravity of less than 10° and a reservoir viscosity of no more than 10 000 centipoises. In this chapter, when reservoir viscosity measurements are not available, extra-heavy oil is considered to have a lower limit of 4° API.

Natural bitumen: natural bitumen is defined as oil having a viscosity greater than 10 000 centipoises under reservoir conditions and an API gravity of less than 10°API. In this chapter, when reservoir viscosity measurements are not available, natural bitumen is taken as having a gravity of less than 4°. (Natural bitumen is immobile in the reservoir. Because of lateral variations in chemistry as well as in depth, and therefore temperature, many reservoirs contain both extra-heavy oil, and occasionally heavy oil, in addition to natural bitumen).