Mar 24, The Shengli Oilfield, under China Petrochemical Corp (Sinopec Group), the country's largest oil refiner, said its Jiyang shale gas oilfield has officially passed a review and documentation process at the Ministry of Natural Resources to become China's first oilfield with a reserve of 100 million tons of shale oil.

Workers patrol at a combined processing station for shale oil of Jiqing Oilfield, in northwest China's Xinjiang Uygur Autonomous Region, Nov. 24, 2024.

The oilfield is the first in China to have its proven reserve certified by the ministry with its specification on shale oil reserve calculation, introduced in January.

The oilfield, in Gaoqing county, East China's Shandong Province, has a proven reserve of more than 140 million tons, of which 11.36 million tons are technically extractable.

Meanwhile, the reserve at Jiyang oilfield is buried deep, under high pressure and formed with complicated geographical conditions. By tapping proprietary drilling theory and technological approach, oil workers extracted some 500,000 tons of shale oil from the oilfield in 2024, while the accumulated crude production exceeded 1 million tons.

Jin Lei, a professor at the China University of Petroleum, told on Sunday that the announcement reflected scientific breakthroughs by China in the exploration of lacustrine shale oil.

"The oilfield is the first to be announced after the introduction of the new state specification governing the calculation of shale oil reserves," Jin said. "This homegrown metric is more suited to the concrete conditions of China's shale oil reserves, and reduced reliance on the US method, which is rooted in evaluating marine shale oil, facilitating domestic shale oil exploration."

Shale oil mainly refers to liquid hydrocarbons that are 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 rocks, sandstones, and siltstones.

According to official data, China's crude oil output reached 213 million tons in 2024, while shale oil production surpassed a record high of 6 million tons.

A total of three national-level shale oil demonstration zones have been established in China's Xinjiang Uygur Autonomous Region, Heilongjiang Province and Shandong Province.