Oil

SIEC section 4. One of the ten top-level sections of the Standard International Energy Product Classification (SIEC); see that page for the classification’s scope rules, coding system and full Table 3.1 code list. Oil is SIEC’s largest and most disaggregated fuel section, running from crude extraction (division 41) through the fully refined oil products (division 46).

4 Oil

Liquid hydrocarbons of fossil origin, comprising: (i) crude oil; (ii) liquids extracted from natural gas (NGL); (iii) fully or partly processed products from the refining of crude oil; and (iv) functionally similar liquid hydrocarbons and organic chemicals from vegetal or animal origins [IRES, Ch. III, SIEC 4, PDF p. 44, 2018].

41 / 410 / 4100 Conventional crude oil

A mineral oil of fossil origin extracted by conventional means from underground reservoirs, comprising liquid or near-liquid hydrocarbons and associated impurities such as sulphur and metals [IRES, Ch. III, SIEC 4100, PDF p. 44, 2018].

Remark: Conventional crude oil exists in the liquid phase under normal surface temperature and pressure and usually flows to the surface under reservoir pressure (conventional extraction). Crude oil includes condensate from condensate fields and field or lease condensate extracted with the crude oil. Crude oils may be classified by sulphur content (sweet or sour) and API gravity (heavy or light); there are no rigorous specifications, but a heavy crude oil may be assumed to have an API gravity below 20° and a sweet crude oil less than 0.5 per cent sulphur content [IRES, Ch. III, SIEC 4100, PDF p. 44, 2018].

42 / 420 / 4200 Natural gas liquids (NGL)

A mixture of ethane, propane, butane (normal and iso), (iso)pentane and a few higher alkanes, collectively referred to as pentanes plus [IRES, Ch. III, SIEC 4200, PDF p. 44, 2018].

Remark: NGL are produced in association with oil or natural gas and are removed in field facilities or gas separation plants before the gas is sold. All NGL components except ethane are either liquid at the surface or are liquefied for disposal. The definition above is the most commonly used, though some usage instead groups components by vapour pressure into three groups of increasing vapour pressure: condensates, natural gasoline and liquefied petroleum gas. NGL may be distilled with crude oil in refineries, blended with refined oil products, or used directly. NGL differs from LNG (liquefied natural gas), which is natural gas liquefied after its NGL has already been removed [IRES, Ch. III, SIEC 4200, PDF pp. 44–45, 2018].

NGL is classified separately from liquefied petroleum gas (LPG) even though both contain propane: NGL is a less-refined mix, while LPG refers to a mix containing only propane and butane — see SIEC Classification System for this and other physically-similar-but-distinct SIEC examples [IRES, Ch. III, para. 3.14, PDF p. 36, 2018].

43 / 430 / 4300 Refinery feedstocks

Oils or gases from crude oil refining, or from processing hydrocarbons in the petrochemical industry, that are destined for further processing in the refinery, excluding blending. Typical feedstocks include naphthas, middle distillates, pyrolysis gasoline, and heavy oils from vacuum distillation and petrochemical plants [IRES, Ch. III, SIEC 4300, PDF p. 45, 2018].

Because the feedstocks definition is primarily based on intended use, no explicit CPC/HS code link is given in Table 3.1 to avoid misleading readers; feedstocks may cover a wide range of products, including naphthas (HS 2710.11) and pyrolysis gasoline (HS 2707.50), among others [IRES, Ch. III, Table 3.1, note (a), PDF p. 39, 2018]. Feedstocks are also a worked example of SIEC’s origin/intended-use classification logic: a product such as naphtha may appear elsewhere in SIEC by composition, but is classified as a feedstock when its destined use is further refinery processing [IRES, Ch. III, para. 3.14, PDF p. 36, 2018].

44 / 440 / 4400 Additives and oxygenates

Compounds added to or blended with oil products to modify their properties (octane, cetane, cold properties, etc.) [IRES, Ch. III, SIEC 4400, PDF p. 45, 2018].

Remark: Examples are (a) oxygenates such as alcohols (methanol, ethanol) and ethers — MTBE (methyl tertiary butyl ether), ETBE (ethyl tertiary butyl ether), TAME (tertiary amyl methyl ether); (b) esters (e.g. rapeseed or dimethylester); and (c) chemical compounds such as TML (tetra methyl lead), TEL (tetra ethyl lead) and detergents. Some additives/oxygenates may be derived from biomass, others from fossil hydrocarbons [IRES, Ch. III, SIEC 4400, PDF p. 45, 2018].

45 / 450 / 4500 Other hydrocarbons

Non-conventional oils and hydrogen. Non-conventional oils are oils obtained by non-conventional production techniques: those extracted from reservoirs of extra heavy oils or oil sands requiring heating or treatment (e.g. emulsification) in situ before reaching the surface for refining, plus oils extracted from oil sands, extra heavy oils, coal and oil shale that are at or can be brought to the surface without treatment but require processing after mining (ex situ processing). Non-conventional oils may also be produced from natural gas [IRES, Ch. III, SIEC 4500, PDF p. 45, 2018].

Remark: These oils fall into two groups: (i) oils for transformation (e.g. synthetic crudes extracted from extra heavy oils, oil sands, coal and oil shale); and (ii) oils for direct use (e.g. emulsified oils such as orimulsion, and gas-to-liquid (GTL) liquids). Oil sands are also known as tar sands; extra heavy oils are also known as bitumen, but this is not the oil product of the same name made from vacuum distillation residue (defined under class 4695 below). Although not a hydrocarbon, hydrogen is included here unless it is a component of another gas [IRES, Ch. III, SIEC 4500, PDF p. 45, 2018].

This is the division that receives oils extracted from oil shale and oil sands, as distinct from the raw rock itself, which is classified under SIEC section 2 [IRES, Ch. III, SIEC 2000, PDF p. 43, 2018].

46 Oil products

Products obtained from crude oil, non-conventional oils, or gases from oil and gas fields — produced through the refining of conventional crude and non-conventional oils, or during the separation of natural gas from gases extracted from oil or gas fields [IRES, Ch. III, SIEC 46, PDF p. 45, 2018].

461 / 4610 Refinery gas

A mixture of non-condensable gases, mainly hydrogen, methane, ethane and olefins, obtained during distillation of crude oil or treatment of oil products (e.g. cracking) in refineries or from nearby petrochemical plants [IRES, Ch. III, SIEC 4610, PDF p. 45, 2018].

Remark: Used mainly as a fuel within the refinery [IRES, Ch. III, SIEC 4610, PDF p. 45, 2018].

462 / 4620 Ethane

A naturally gaseous straight-chain hydrocarbon (C2H6) [IRES, Ch. III, SIEC 4620, PDF p. 45, 2018].

Remark: Obtained at gas separation plants or from crude oil refining. A valuable feedstock for petrochemical manufacture [IRES, Ch. III, SIEC 4620, PDF p. 45, 2018].

463 / 4630 Liquefied petroleum gases (LPG)

Liquefied propane (C3H8) and butane (C4H10), or mixtures of both. Commercial grades are usually mixtures of these gases with small amounts of propylene, butylene, isobutene and isobutylene, stored under pressure in containers [IRES, Ch. III, SIEC 4630, PDF p. 46, 2018].

Remark: The propane/butane mixture varies by purpose and season. The gases may be extracted from natural gas at gas separation plants or at plants regasifying imported LNG, and are also obtained during crude oil refining. LPG may be used for heating and as a vehicle fuel. See also the definition for natural gas liquids; certain oil field practices also use the term LPG to describe the high-vapour-pressure components of NGL [IRES, Ch. III, SIEC 4630, PDF p. 46, 2018].

464 / 4640 Naphtha

Light or medium oils distilling between 30°C and 210°C that do not meet the specification for motor gasoline [IRES, Ch. III, SIEC 4640, PDF p. 46, 2018].

Remark: Different naphthas are distinguished by density and the content of paraffins, isoparaffins, olefins, naphthenes and aromatics. Mainly used as feedstock for high-octane gasolines and for olefin manufacture in the petrochemical industry [IRES, Ch. III, SIEC 4640, PDF p. 46, 2018].

465 Gasolines

Complex mixtures of volatile hydrocarbons distilling between approximately 25°C and 220°C, consisting of compounds in the C4 to C12 range [IRES, Ch. III, SIEC 465, PDF p. 46, 2018].

Remark: Gasolines may contain blending components of biomass origin, especially oxygenates (mainly ethers and alcohols), and additives may be used to boost performance [IRES, Ch. III, SIEC 465, PDF p. 46, 2018].

4651 Aviation gasoline

Gasoline prepared especially for aviation piston engines, with additives that assure performance under flight conditions; predominantly alkylates (obtained by combining C4 and C5 isoparaffins with C3, C4 and C5 olefins), with the possible addition of more aromatic components including toluene. Distillation range 25°C to 170°C [IRES, Ch. III, SIEC 4651, PDF p. 46, 2018].

4652 Motor gasoline

A mixture of some aromatics (e.g. benzene and toluene) and aliphatic hydrocarbons in the C5 to C12 range. Distillation range 25°C to 220°C [IRES, Ch. III, SIEC 4652, PDF p. 46, 2018].

Remark: Additives are blended to improve octane rating, combustion performance, storage-oxidation resistance, engine cleanliness and catalytic-converter pollutant capture. Motor gasoline may also contain biogasoline products when blended [IRES, Ch. III, SIEC 4652, PDF p. 46, 2018].

4653 Gasoline-type jet fuel

Light hydrocarbons for use in aviation turbine power units, distilling between 100°C and 250°C, obtained by blending kerosene and gasoline or naphtha such that aromatic content does not exceed 25 per cent by volume and vapour pressure is between 13.7 kPa and 20.6 kPa [IRES, Ch. III, SIEC 4653, PDF p. 46, 2018].

Remark: Also known as aviation turbine fuel [IRES, Ch. III, SIEC 4653, PDF p. 46, 2018].

466 Kerosenes

Mixtures of hydrocarbons in the range C9 to C16, distilling over the temperature interval 145°C to 300°C (but not usually above 250°C) with a flash point above 38°C [IRES, Ch. III, SIEC 466, PDF p. 47, 2018].

Remark: Chemical composition depends on the source crude oil and refinery processes used. Kerosenes obtained from crude oil by atmospheric distillation are known as straight-run kerosenes; such streams may be further treated to produce kerosenes acceptable for blending as jet fuels. Kerosenes are primarily used as jet fuels, but also as domestic heating and cooking fuels and as solvents, and may include biomass-derived components or additives when blended [IRES, Ch. III, SIEC 466, PDF p. 47, 2018].

4661 Kerosene-type jet fuel

A blend of kerosenes suited to flight conditions with particular specifications, such as freezing point [IRES, Ch. III, SIEC 4661, PDF p. 47, 2018].

Remark: Specifications are set by a small number of national standards committees, notably ASTM (United States of America), MOD (United Kingdom), and GOST (Russia) [IRES, Ch. III, SIEC 4661, PDF p. 47, 2018].

4669 Other kerosene

Kerosene used for heating, cooking, lighting, solvents and internal combustion engines [IRES, Ch. III, SIEC 4669, PDF p. 47, 2018].

Remark: Also known as burning oil, vaporizing oil, power kerosene and illuminating oil [IRES, Ch. III, SIEC 4669, PDF p. 47, 2018].

467 Gas oil/diesel oil and heavy gas oil

Gas oils and heavy gas oils [IRES, Ch. III, SIEC 467, PDF p. 47, 2018].

4671 Gas oil/diesel oil

Middle distillates, predominantly of carbon number range C11 to C25, with a distillation range of 160°C to 420°C [IRES, Ch. III, SIEC 4671, PDF p. 47, 2018].

Remark: The principal marketed products are fuels for diesel engines (diesel oil), heating oils, and marine fuel. Gas oils are also used as middle-distillate feedstock for the petrochemical industry and as solvents [IRES, Ch. III, SIEC 4671, PDF p. 47, 2018].

4672 Heavy gas oil

A mixture of predominantly gas oil and fuel oil, distilling in the range of approximately 380°C to 540°C [IRES, Ch. III, SIEC 4672, PDF p. 47, 2018].

468 / 4680 Fuel oil

Comprises residual fuel oil and heavy fuel oil. Residual fuel oils have a distillation range of 350°C to 650°C and a kinematic viscosity in the range 6 to 55 cSt at 100°C, a flash point always above 60°C and specific gravity above 0.95. Heavy fuel oil is a general term for a blended product based on residues from various refinery processes [IRES, Ch. III, SIEC 4680, PDF p. 47, 2018].

Remark: Other names include bunker fuel, bunker C, fuel oil No. 6, industrial fuel oil, marine fuel oil and black oil. Residual and heavy fuel oil are used in medium to large industrial plants, marine applications and power stations, in boilers, furnaces and diesel engines; residual fuel oil is also used as fuel within the refinery [IRES, Ch. III, SIEC 4680, PDF pp. 47–48, 2018].

469 Other oil products

Oil products not covered in groups 461–468 [IRES, Ch. III, SIEC 469, PDF p. 48, 2018].

4691 White spirit and special boiling point industrial spirits

Refined distillate intermediates with a distillation in the naphtha/kerosene range, mainly used for non-fuel purposes, sub-divided as: (a) white spirit — an industrial spirit with a flash point above 30°C and a distillation range of 135°C to 200°C; and (b) industrial spirit (SBP) — light oils distilling between 30°C and 200°C [IRES, Ch. III, SIEC 4691, PDF p. 48, 2018].

Remark: There are seven or eight grades of industrial spirits, depending on the position of the cut in the distillation range, defined by the temperature difference between the 5 per cent and 90 per cent volume distillation points (not more than 60°C). White spirit and industrial spirits are mostly used as thinners and solvents [IRES, Ch. III, SIEC 4691, PDF p. 48, 2018].

4692 Lubricants

Oils produced from crude oil, for which the principal use is to reduce friction between sliding surfaces and during metal cutting operations [IRES, Ch. III, SIEC 4692, PDF p. 48, 2018].

Remark: Lubricant base stocks are obtained from vacuum distillates resulting from further distillation of the residue from atmospheric distillation of crude oil, then further processed to produce lubricants with the desired properties [IRES, Ch. III, SIEC 4692, PDF p. 48, 2018].

Lubricants are SIEC’s own worked example of the non-energy-use scope rule: although ordinarily used for non-energy purposes, their production and consumption are recorded in energy statistics because they are an output of crude oil refining — see Energy Products for the full lubricants-vs-plastics comparison [IRES, Ch. III, para. 3.9, PDF p. 35, 2018].

4693 Paraffin waxes

Residues extracted when dewaxing lubricant oils, with a crystalline structure varying in fineness by grade; colourless, odourless and translucent, with a melting point above 45°C [IRES, Ch. III, SIEC 4693, PDF p. 48, 2018].

Remark: Also known as petroleum waxes [IRES, Ch. III, SIEC 4693, PDF p. 48, 2018].

4694 Petroleum coke

A black solid obtained mainly by cracking and carbonizing heavy hydrocarbon oils, tars and pitches, consisting mainly of carbon (90 to 95 per cent) with a low ash content [IRES, Ch. III, SIEC 4694, PDF p. 48, 2018].

The two most important categories are green coke and calcined coke. Green coke (raw coke) is the primary solid carbonization product from high-boiling hydrocarbon fractions obtained at temperatures below 630°C, containing 4–15 per cent by weight of matter releasable as volatiles during subsequent heat treatment up to approximately 1330°C. Calcined coke is a petroleum coke or coal-derived pitch coke obtained by heat-treating green coke to about 1330°C, and will normally have a hydrogen content below 0.1 per cent by weight [IRES, Ch. III, SIEC 4694, PDF pp. 48–49, 2018].

Remark: In many catalytic operations (e.g. catalytic cracking), carbon or catalytic coke deposits on the catalyst, deactivating it; the catalyst is reactivated by burning off the coke, which is used as a fuel in the refining process. This coke is not recoverable in a concentrated form [IRES, Ch. III, SIEC 4694, PDF p. 49, 2018].

4695 Bitumen

A solid, semi-solid or viscous hydrocarbon with a colloidal structure, brown to black in colour [IRES, Ch. III, SIEC 4695, PDF p. 49, 2018].

Remark: Obtained as a residue in the distillation of crude oil and by vacuum distillation of oil residues from atmospheric distillation. Should not be confused with the non-conventional primary extra heavy oils that may also be called bitumen (see division 45 above). Besides its major use for road pavements, bitumen is also used as an adhesive, a waterproofing agent for roof coverings, and a binder in patent fuel manufacture, and may be used for electricity generation in specially designed power plants. Bitumen is also known in some countries as asphalt, though in others “asphalt” describes the mixture of bitumen and stone aggregate used for road pavements [IRES, Ch. III, SIEC 4695, PDF p. 49, 2018].

4699 Other oil products n.e.c.

Products (including partly refined products) from the refining of crude oil and feedstocks not specified above [IRES, Ch. III, SIEC 4699, PDF p. 49, 2018].

Remark: Includes basic chemicals and organic chemicals destined for use within the refinery or for sale to or processing in the chemical industry, such as propylene, benzene, toluene and xylene [IRES, Ch. III, SIEC 4699, PDF p. 49, 2018].

Chapter VI’s reference list of data items defines backflows from the petrochemical industry to refineries, refinery intake, refinery losses, and direct use of crude oil/NGL as oil-specific data items (4.1–4.4), plus refinery capacity as a production-capacity data item — see Data Items on Energy Flows and Stocks and Production, Storage and Transmission Capacity [IRES, Ch. VI, paras 6.50–6.54, 6.67, PDF pp. 93, 95, 2018].

Related

• SIEC Classification System — SIEC’s scope rules, coding system and full Table 3.1 code list, of which this section is one entry; also covers the NGL/LPG and feedstocks classification examples in more detail
• Energy Products — the general energy-product definition, the SIEC scope-precision rules (fuels vs. fossil-fuel-derived products), and the lubricants worked example
• Natural Gas — the preceding SIEC fuel section; NGL is removed from natural gas during processing
• Oil Shale/Oil Sands — oils extracted from oil shale/oil sands are classified in this section’s division 45 (Other hydrocarbons)
• Biofuels — the next SIEC fuel section
• Data Items on Energy Flows and Stocks — the backflows, refinery intake/losses, and direct-use data items
• Production, Storage and Transmission Capacity — the refinery-capacity data item