Last December marked the 10th anniversary of the launch of the Turkmenistan-Uzbekistan-Kazakhstan-China gas pipeline. The interstate highway includes three parallel lines (A, B, and C), each of which is 1,830 km long. Gas coming from Central Asia is supplied to the population of 22 provinces and autonomous regions of the China, which is more than 500 million people.

To date, about 300 billion cubic meters of natural gas has been exported from Central Asia to China. More than 80 percent of this volume was supplied to the pipeline from Turkmen fields, primarily operated by the State concern "Türkmengaz".

In accordance with interstate agreements, in the future, Turkmen gas supplies to China will increase to 65 billion cubic meters per year. This will be possible after the construction of the fourth line of the gas pipeline D, which will be laid from the border of Turkmenistan through the territory of Uzbekistan, Tajikistan and Kyrgyzstan. Its total length is about 1000 km, and its capacity is 30 billion cubic meters of gas per year.

Tajikistan has registered standards related to the construction of the fourth line of the Central Asia-China gas pipeline.

As noted in the China Petroleum News, the D line is intended to become an important energy channel connecting China with Central Asia. At the same time, this project is one of the most complex in the world history of construction of land pipelines. The length of the gas pipeline in Tajikistan is 391 km, its route will pass mainly through mountainous and hilly areas.

Currently, two standards for operation and maintenance of line D of the Central Asia-China gas pipeline have been registered, as well as 14 standards for the construction of tunnels on its route. They were developed by specialists of the China Petroleum Pipeline company of the Chinese national petroleum Corporation (CNPC) and The Research Institute "Construction and architecture" Of the Committee on architecture and construction under the Government of the Republic of Tajikistan.