China’s Sinopec, Asia’s largest oil refiner, has started production in the first phase of its Fuling shale gas project in the Sichuan Basin of a southwest province with an annual capacity of 5bcm, reported China Daily.

Sinopec said in a statement, that its goal was to accelerate the shale gas exploration to reach a production capacity of 10bcm by 2017. The Fuling field, discovered in 2012, has explored reserves of 380.6bcm of shale gas, Business Standard informed.

Shale gas is a type of unconventional natural gas trapped in shale or mud-stone formations and it is mainly composed of methane, considered to be a type of new, clean energy source. The move is expected to help optimize China’s envisioned energy mix.