Major hydrocarbon corridors — {{km}} km mapped across {{count}} countries
The world's network of gas and oil pipelines — a linear layer. Per-country mileage is derived by cutting the very same routes shown on the map, never from a separate ranking source.
OpenStreetMap: named corridors (`relation route=pipeline`) where they exist, supplemented by major transmission segments (`usage=transmission`) grouped by name elsewhere. This is NOT a full inventory of national networks: against Global Energy Monitor, coverage ranges from about 90% (Germany, Russia) to about 20% (India, Algeria) — both the legend and the ranking's footer say so.
A thin line isn't easy to hit at world zoom: every route carries a dark halo and a colour by type (gas/oil).
The United States (259,000 km recorded) and Russia (118,000 km) dominate a ranking whose gap with third place, Argentina (15,000 km), measures the scale of their lead — fitting for two of the world's largest hydrocarbon producers and consumers, with territory vast enough to warrant a developed internal transport network.