OREANDA-NEWS.  June 10, 2014. The third line of the Central Asia-China gas pipeline network is expected to be fully operational at the end of 2015, by which time it will nearly double the existing gas transmission capacity from Turkmenistan to China to 55 billion cubic meters/year, state company China National Petroleum Corp said.

The valves of the so-called Line C within Uzbekistan were opened Saturday and started receiving Turkmen gas, but the entire pipeline and its supporting infrastructure and processing units will only be completed by the end of next year, the company said.

The 1,830-km (1,137-mile) Line C runs parallel to the existing A and B lines of the Central Asia-China route, which are already in operation and have total capacity of 30 Bcm/year.

Line C has a transmission capacity of 25 Bcm/year. It starts at Gedaim on the Turkmen-Uzbek border, runs through Uzbekistan and Kazakhstan and ends at the border town of Khorgos in China's far western Xinjiang province, where it will link up with CNPC's domestic Third West-East gas pipeline currently still being developed.

In September 2011, CNPC and Uzbekistan's state-owned Uzbekneftegaz signed an agreement for the construction and operation of the Uzbek section of Line C and construction started the following year. Overall welding work was completed by the end of last year, CNPC said.

Once commissioned, the A, B and C lines will be able to fulfill 20% of China's total domestic natural gas demand, CNPC said.

China started importing Turkmen gas in late 2009. CNPC and state-owned Turkmengaz signed an initial sales and purchase agreement in July 2007 for China to import 30 Bcm/year of Turkmen gas for 30 years. In 2008, the two companies agreed to boost the volume to 40 Bcm/year by 2015 and this was later lifted to 65 Bcm/year by 2020 in November 2011.

Last month, however, both countries agreed to accelerate imports and brought forward the 65 Bcm/year target to 2016. Some of the additional gas supplies would come from the supergiant Galkynysh gas field -- previously known as South Yolotan -- in Turkmenistan, which both sides agreed to jointly develop last year.

China imported roughly 24.4 Bcm of gas from Turkmenistan last year, a 22% increase from 2012, according to Chinese customs data. It also imported 2.9 Bcm from Uzbekistan via the pipeline network last year.

Uzbekneftegaz agreed to supply 10 Bcm/year of gas to CNPC in mid-2010. Uzbek gas volumes to China are expected to rise once Line C is commissioned.

The A, B and C lines will be supplemented by a fourth line -- D -- where construction is expected to start later this year. It will run through Uzbekistan, Tajikistan and Kyrgyzstan to deliver Turkmen gas to China.

By the end of China's 13th Five-Year Plan in 2020, all four lines in the network will be able to supply China with 80 Bcm/year of gas, accounting for at least 40% of China's total imported gas supplies, CNPC said in March.