Central Asia–Center gas pipeline system

Location	Turkmenistan, Uzbekistan, Kazakhstan, Russia
General direction	south–north-east
From	Dauletabad gas field and Okarem, Turkmenistan
Passes through	Shatlyk gas field, Khiva, Kungrad, Cheleken, Beyneu
To	Alexandrov Gay, Border of Kazakhstan/Russian Federation
Runs alongside	Amu Darya
General information
Type	natural gas
Partners	Gazprom Türkmengaz Uzbekneftegas KazMunayGas
Commissioned	1969
Length	2,000 km

The Central Asia – Center gas pipeline system was the first truly ‘transcontinental gas trunk line system’ in the former Soviet Union connecting the gas fields of Turkmenistan, Kazakhstan and Uzbekistan to industrially advanced regions of central Russia. The  construction and operation of this system  required advanced solutions for long-distance gas transmission in harsh natural and climatic conditions. It was the first system to use large 1,200 to 1,400 millimetre pipes that afterwards were widely accepted as standards for gas trunk line construction in Russia. Today the pipeline system is controlled by Gazprom and consists of a system of natural gas pipelines run from Turkmenistan via Uzbekistan and Kazakhstan to Russia. The eastern branch includes the Central Asia - Centre (CAC) 1, 2, 4 and 5 pipelines, which start from the south-eastern gas fields of Turkmenistan. The western branch consists of the CAC-3 pipeline and a project to build a new parallel Caspian pipeline. The western branch runs from the Caspian Sea coast of Turkmenistan to north. The branches meet in western Kazakhstan. From there the pipelines run to north where they are connected to the Russian natural gas pipeline system.

History - The system was built between 1960 and 1988. Construction began after discovery of Turkmenistan's Dzharkak field in the Amu Darya Basin, and the first section of the pipeline was completed in 1960. CAC-1 and 2 were commissioned in 1969 and CAC-4 was commissioned in 1973. In 1976, two parallel lines were laid between Shatlyk compressor station and Khiva. CAC-5 was commissioned in 1985 and in 1986-88 the Dauletabad–Khiva line was connected. The western branch CAC-3 was constructed in 1972-1975.

Technical features - Almost all Uzbek and Turkmen natural gas is delivered through the CAC pipeline system, mainly through the eastern branch due to location of production sites and poor technical condition of the western branch. CAC-1, 2, 4 and 5 pipelines are supplied from gas fields in the South-East of Turkmenistan, mainly from the Dauletabad gas field. The eastern branch starts from the Dauletabad field and continues through the Shatlyk gas field east of Tejen to Khiva, Uzbekistan. From there the pipeline system transports gas north-west along Amu Darya to the Kungrad compressor station in Uzbekistan. From Kungrad, most of the gas is carried via Kazakhstan to the Alexandrov Gay gas metering station in Russia. At Alexandrov Gay CAC pipelines meet with Soyuz and Orenburg–Novopskov pipelines. From there two lines run northwest to Moscow, and two others proceed across the Volga river to the North Caucasus-Moscow transmission system. The diameter of most pipelines varies from 1,020 to 1,420 millimeters. Current capacity of the system is 44 billion cubic meters (bcm) per year. An agreement is in place to increase capacity to 55 bcm per year by 2010 and through modernization there is potential to increase capacity to 90 bcm per year. The western branch originates at Okarem near the Turkmenistan–Iran border and runs north. It is supplied by gas from fields scattered along the Caspian coast between Okarem and Balkanabat. It continues via Uzen in Kazakhstan to the Beyneu compressor station, where it meets the eastern branch of the CAC. South of Hazar, the western system consists of 710 millimeters diameter pipeline, and between Hazar and Beyneau 1,220 millimeters diameter pipeline.