BEIJING, Oct. 23 (Xinhua) -- Sinopec, China's largest oil refiner, announced on Thursday the discovery of a new shale oil reserve estimated at 100 million tonnes in Sichuan Basin in southwest China.

The company said that the discovery was made in the Qijiang District of Chongqing Municipality. An exploratory well drilled at the site has achieved a flow rate of 38.64 cubic meters of oil and 10,000 cubic meters of natural gas per day during test production, it said.

Shale oil mainly refers to liquid hydrocarbons trapped in formations of shale rock that can be extracted for refining. It is often found in organic-rich shale and thin interlayers of carbonate rock, sandstone and siltstone. As an unconventional oil and gas resource, it also contributes to stable crude oil production in China.

Sinopec has continued to increase efforts in shale oil exploration and development, having identified three new large-scale shale oil fields. Last year, the company's annual shale oil production reached 705,000 tonnes, up 308,000 tonnes from the previous year.