What Counts as Extraction of Crude Petroleum and Natural Gas in Rev. 5?

In ISIC Rev. 5, published by the UN Statistics Division, this activity covers operating oil and gas wells, extracting crude petroleum, and extracting natural gas, including associated activities such as separating gas and liquids at the well site. Refining crude oil into petrol, diesel, and other products is manufacturing, and transporting oil and gas by pipeline is a transport activity, not extraction itself.

What happens on a producing field, day by day?

Operating wells is the heart of this activity. Wells are drilled for production, oil and gas are brought to the surface, and the mixed stream that comes up is given a basic separation at the well site so that gas and liquids can be handled separately from that point on. That field separation is part of extraction because it belongs to the act of producing the hydrocarbons, not to turning them into finished fuels. It is a practical, on site step: keeping the flow manageable, removing water or solids that came up with the oil and gas, and sending each part onward in a form the next stage can receive.

Onshore and offshore fields share that core, even though everything around it differs. An onshore field may spread wells across a landscape with roads and gathering lines, while an offshore platform concentrates wells, crews, and separation equipment on a single structure far from shore, with supply boats and helicopters replacing roads. Costs and logistics diverge sharply, yet the statistical description does not split on those grounds. In broad terms, a well producing crude or gas is a well producing crude or gas, whether the rig stands in a desert or on a platform at sea.

What does an offshore platform example clarify, and what does it leave out?

An offshore platform producing crude oil and associated gas is a compact illustration of extraction: wells below, separation on the platform, and crude and gas leaving for the next stage. Set beside it, a refinery turning that crude into fuels shows manufacturing, and a pipeline company moving oil and gas shows transport. The three pictures together trace a chain, and each link has its own heading because each link does its own work. Readers sometimes blur the chain because one corporate group may own all three links, or because a single site may host more than one of them. Corporate ownership and site sharing do not merge the headings; the work at each stage still has to be recognised for what it is.

What the example deliberately leaves out is just as important. This guide describes extraction only. It does not determine ownership of reserves, royalties, or licences, which are governed by national law. A platform may be operated by one company, owned in part by others, and licensed under terms that have nothing to do with the statistical heading, and none of those legal facts changes the description of the work. Readers who need the legal picture should go to the licensing authority for that jurisdiction, not to the classification.

What changed in the background between Rev. 4 and Rev. 5?

Rev. 5 did not start from a blank page. ISIC Rev. 5, published by the UN Statistics Division, extends Rev. 4 for extraction of crude petroleum and natural gas, with 22 sections from A to V, 87 divisions, 258 groups, and 463 classes, endorsed by the UN Statistical Commission in March 2023. Some headings for extraction of crude petroleum and natural gas were split, some merged, and some reworded to reflect new ways of working. For oil and gas, that history is a warning against assuming continuity: a series that changes revision may also change heading, even when the wells, the platform, and the daily work look unchanged.

The practical consequence is simple. Always note the revision when a code is quoted, and check correspondence material before treating an old series and a new series as one continuous line. A reader comparing production figures across years needs to know whether a jump or a dip reflects real change in the field or only a change in how the work was described. National guidance often carries that correspondence in a usable form, and the UNSD material is the reference against which it should be checked.

How should a reader work through a doubtful case?

Where an activity seems to fit two headings, compare the full descriptions, not titles alone. Does the work include operating producing wells, or only drilling for someone else? Does it include field separation at the well site, or full refining into fuels? Does it move oil and gas, or produce it? Each question narrows the field, and the answers, written down in plain words, usually point to one heading more strongly than the other. If they do not, that unresolved doubt is itself useful information to take to the record holder, together with the UNSD description that came closest.

Nothing here settles an individual case, because this is statistical classification material only: it does not decide any reader’s code, principal activity, or registration. For a formal entry, take the plain description of the work to the national statistical institute or business register that holds the record and ask that body to confirm the heading.