A controversial natural gas pipeline delivering gas to China from Myanmar has been brought into use.

The $2.5bn (£1.6bn) pipeline stretches from Myanmar's deepwater Shwe fields to China's south-western Yunnan province. It took three years to complete and is 493 miles long.

The pipeline’s annual throughput capacity is 12 billion cubic metres (1.16 Bcf per day). Gas production is currently at 58,550 Mcf per day but is expected to increase to 500,000 Mcf per day.

A 478 mile crude oil pipeline is also under construction as part of the Myanmar-China Oil and Gas Pipeline project, with a transmission capacity of 22 million tons per year (440,000 barrels of oil per day). Once the whole project is completed, two million tons of crude oil and 20 per cent of the gas output will be offloaded in Myanmar.

The project is strategically important for both countries, allowing China to boost and diversify imports of cleaner burning fuel while increasing revenues for Myanmar and helping it address its own acute domestic energy shortages.

However concerns have been raised over environmental and safety factors, while a flare-up in anti-Chinese sentiment in Myanmar has raised security concerns.

Earlier this year protests were held in China over the building of a refinery and petrochemicals base to process the crude oil being piped in, while hundreds protested in Myanmar saying they had given up their land for too little compensation and that salaries offered for local workers on the pipeline were too low.

Guerrillas also attacked a Myanmar oil and gas compound near the pipelines in Shan State near the Chinese border, killing two people. This increased concerns over whether the authorities would be able to adequately secure the pipelines.

China has targeted increasing its natural gas usage from less than 5 per cent of the country's energy mix to 10 per cent by 2020. While it already imports liquid natural gas from several countries including Indonesia, Australia and Qatar, it had only imported natural gas from Turkmenistan and Uzbekistan until now.