The following map, even though not 100% accurate, depicts the most important European natural gas pipeline networks. These are the main arteries of course, and each artery has many branches which do not appear on the map.
With yellow you can see the pipelines of Sonatrach, the Algerian state owned energy giant, with red you can see the pipelines of the Russian state owned giant Gazprom, and with green you can see the pipelines of the state owned Norwegian giant Statoil. Russia is Europe’s largest natural gas supplier, Norway is the second largest, Algeria is the third, Qatar is the fourth, Nigeria is the fifth, and Libya is the sixth, as you can see at the following table from Eurostat (for 2012).
Sonatrach in Algeria, and Gazprom in Russia, have the exclusive right to export natural gas. That means they can cooperate with other companies in Algeria and Russia, but only they have the right to export Algerian and Russian natural gas.
With yellow you can see the Maghreb-Europe Pipeline (Algeria-Morocco-Spain), the Medgaz Pipeline (Algeria-Spain), the GALSI Pipeline (Algeria-Italy), and the Trans-Mediterranean Pipeline (Algeria-Tunisia-Italy). I must say that the GALSI pipeline, which is supposed to connect Algeria and Italy through Sardinia, Italy’s second largest island, has not been constructed yet. Moreover the Trans-Mediterranean Pipeline is not correctly sketched on the map, because it does not pass through Tunisia before reaching Italy.
With light green you can see the Green Stream Pipeline (Libya-Italy), which was inaugurated by Qaddafi and Berlusconi in 2004.
With green you can see Europipe 1 (Norway-Germany), Europipe 2 (Norway-Denmark-Germany), Franpipe (Norway-France), Langeled (Norway-England), Scanled (Norway-Sweden-Denmark), which does not appear on the map, Vesterled (Norway-Scotland), and Zeepipe (Norway-Belgium).
With red you can see the Nord Stream pipeline (Russia-Germany), the Yamal-Europe pipeline (Russia-Ukraine), and the Blue Stream pipeline (Russia-Turkey). The Blue Stream pipeline which connects Russia and Turkey through the Black Sea did not appear on the map and I had to sketch it.
I do not know which one is the orange pipeline. Such a pipeline does not exist. Maybe it wants to show the effort made by the EU, Turkey and the US to connect the Caspian Sea with Europe through Turkey, but the pipelines that have been discussed so far i.e. Nabucco and TANAP-TAP, do not pass through the Black Sea. Maybe it is a pipeline that was considered in the past and it was later dropped, and I have not heard about it. The only pipeline networks which are discussed and do indeed pass through the Black Sea, are the Russian South Stream and the Turk Stream pipelines, both of which are having very hard times until now (September 2015), and they did not go ahead.
Today most of the revenue of the energy exporting countries still comes from oil. That is true even for Qatar, which is the 3rd richest country in the world in terms of natural gas reserves, and it is not even in the first ten richest countries when it comes to oil reserves. But natural gas is growing in importance because it is friendlier for the environment. Moreover when natural gas is sold though pipelines it creates geopolitical addictions, because these networks are very expensive and require huge investments. Therefore before such networks are built, the selling and buying countries always sign long term agreements which significantly affect their foreign policies. You see how the Russo-German pipelines have affected Germany’s behavior as a NATO country.
Moreover when a natural gas pipeline network is constructed it is very difficulty to import liquefied natural gas (LNG), because LNG is very expensive. LNG must be converted to liquid form in the selling country’s facilities, in order to be carried by special and very expensive ships, and when it reaches the buying country it must be converted to its original form before it can be used. This process involves very large costs. On the contrary a pipeline network is very expensive to construct, but once constructed it does not involve significant costs to carry the gas from the selling to the buying country.
Finally the oil market is a very old and a very well organized market, and prices are determined each day internationally by demand and supply. When the price is 50 dollars per barrel everybody sells for 50 dollars. When the price is 150 dollars everybody sells for 150 dollars. That is not the case for natural gas. Natural gas prices are agreed between individual sellers and buyers, and buyers can charge lower prices to friendly governments, and higher prices to non-friendly governments. That’s what the European Union is accusing Russia of doing to the countries of the EU.
What we definitely see happening is that while oil was the main cause of war in the 20th century, natural gas has been the main cause of war in the beginning of the 21st century. Oil is still a very important cause of war, but the importance of the role of natural gas in international warfare has dramatically increased.
Richest Countries in Natural Gas Reserves (richest is Russia not Algeria)