Across China: Depleted gas fields turned into underground storage facilities

SHENYANG, Jan. 17 (Xinhua) -- An underground natural gas storage facility, rebuilt from a depleted oil and gas field, has played an important role in stabilizing gas supply in China's chilly Liaoning Province this winter.

The storage facility in Panjin city, dubbed double 6 gas reserve, is holding 4 billion cubic meters of natural gas in 15 depleted wells and is supplying up to 10 million cubic meters of natural gas every day.

The wells were part of the Liaohe oilfields, one of the largest in the country. Work to turn them into storage facility began in 2011 as production dried up. From April 2014 it started to be filled with natural gas.

Double 6 is the first such underground gas storage facility in northeast China.

This kind of underground natural gas storage facility functions as a market stabilizer, unloading its storage when supply is short and increasing its storage when demand is weak.

Currently, most underground gas storage facilities in China are rebuilt from depleted natural gas fields. Compared with gas tanks above the ground, underground gas storage facilities are safer and more durable, with larger storage capacity and lower costs.

The first example of natural gas successfully being stored underground happened in Canada in 1915. The underground natural gas storage field was developed from a depleted natural gas well.

The first such facility in China was built in Tianjin in 1999.

"So far, there are 25 underground gas storage facilities in China," said Guo Jiaofeng, a researcher of the Development Research Center of the State Council.

"These facilities are designed to store 41.5 billion cubic meters of natural gas with a working storage capacity of 18 billion cubic meters. But compared with the nation's huge demand, such facilities are far from enough to hedge against shortage in supply," Guo said.

As China moves to curb air pollution and promote new energy in recent years, demands for natural gas have increased rapidly.

"At the end of 2017, the volume of underground natural gas storage was only equivalent to 4 percent of the country's consumption, while the average world level is 12 percent," Guo said.

China's natural gas consumption in 2017 increased to 240 billion cubic meters. The figure is expected to soar to 500 billion cubic meters in 2030.

"Based on the trend, the volume of underground natural gas storage should increase at least two times more than its current scale," Guo said.

The National Development and Reform Commission, the Ministry of Science and Technology and other related departments have made policies to support the building of underground natural gas storage facilities.

"A survey of depleted oil and gas fields across the country is now underway to make a construction plan of underground natural gas storage facilities," said Ding Guosheng, an expert with Chinese oil giant CNPC. Enditem