BEIJING - China National Petroleum Corp (CNPC) , the country's biggest oil and gas producer, plans to deepen its cut on methane emissions and set a more ambitious pledge than its previous commitment to the Oil and Gas Climate Initiative (OGCI).

"CNPC lowered methane emission intensity by 12.3% in 2019 from the baseline of 2017. Above that, we expect to further slash 50% by 2025 and strive to reach world's first-class methane emission management level," the company said in a statement on Thursday.

Methane is emitted during the production and transport of coal, natural gas, and oil. More than 40% of China's methane is emitted during upstream gas and oil operations and coal production.

As a member of OGCI - a consortium of 12 world's leading energy firms that aims to accelerate the industry response to climate change - CNPC two years ago had pledged to reduce by 2025 the average methane intensity to below 0.25% from 2017 level, with the ambition to achieve 0.2%.

CNPC's methane emission intensity stood at 0.32% in 2017.

The company said it has installed 48 methane emission recycling station at Tarium oilfield in the northwestern region of Xinjiang, with recycling capacity of 4.2 million cubic metres per day.

The recycling capacity for associated gas, mainly methane and some ethane, at Changqing oilfield in Shaanxi province reached 1 billion cubic metres per annum.

CNPC also plans to strengthen the task of emission monitoring and plugging methane leaks, to upgrade or replace equipment at oilfield and to minimise flaring. In January, a senior Chinese climate change official said China will consider to roll out a campaign to control methane emissions when condition permits, as part of a more ambitious pledge to the Paris Accord.

China's total annual methane emission was around 1.125 billion tonnes, about 9.1% of total greenhouse gas emissions, according to the last full inventory covering the year 2014.

(Reporting by Muyu Xu and Chen Aizhu, Editing by Sherry Jacob-Phillips) ((muyu.xu@thomsonreuters.com; +86 10 56692117;))