In a move that could shift both economic and strategic balances in the South China Sea, China’s state-owned energy giant CNOOC (China National Offshore Oil Corporation) has announced the discovery of a major offshore oilfield with reserves surpassing 100 million metric tons.
Reported by the official Xinhua news agency on March 31, the find marks one of the country’s largest energy discoveries in recent years and adds a powerful new dimension to a region already laden with territorial tensions.
Oil and Gas in the Pearl River Mouth Basin
The new oilfield, named Kaiping South, lies in the Pearl River Mouth Basin, located in the eastern part of the South China Sea. This area has long been considered one of China’s most promising offshore zones, and the latest data from CNOOC suggests that its resource potential is being confirmed at scale.
According to the company, the Kaiping South field contains approximately 102 million tons of crude oil, in addition to more than 380 billion cubic feet (10.9 billion cubic meters) of natural gas.
The reserves were confirmed through exploratory drilling at the Kaiping South 1-1 well, which reached a depth of 3,462 meters and penetrated a vertical thickness of 35.2 meters of oil- and gas-bearing layers. The well’s location is approximately 300 kilometers off the coast of Guangdong province.
This find adds considerable weight to China’s push for deeper offshore resource development, a central pillar of its national energy security strategy. The Kaiping South structure belongs to the Enping Sag within the basin, which had already attracted attention due to earlier discoveries nearby.
This latest success indicates that CNOOC’s long-term geological assessments of the area are paying off, confirming substantial commercial reserves in previously underexplored formations.
Strategic Implications in Contested Waters
While the discovery marks a technical and economic success, it is equally significant from a geopolitical standpoint. The South China Sea is a hotly contested region, with overlapping maritime claims from several countries, including Vietnam, the Philippines, Malaysia, and Brunei.
China’s expansive claim, defined by its self-declared “nine-dash line,” has been a persistent source of regional friction, and the addition of a major offshore oilfield to its holdings is likely to further heighten sensitivities.
Although the Kaiping South field is situated within China’s undisputed territorial waters, its symbolic value and proximity to broader contested zones may prompt scrutiny from neighboring states and international observers alike.
China has increasingly used large-scale offshore energy projects to reinforce its presence in the region, and the Kaiping South development follows a string of similar efforts aimed at deepening economic integration with the South China Sea. Such infrastructure projects often serve dual purposes: boosting domestic energy production while anchoring long-term strategic claims.
As offshore oil continues to play a central role in the region’s economic and political calculus, the discovery could add fuel to diplomatic tensions, particularly as resource scarcity and energy security become more pronounced global concerns.
A Showcase of Deep-Sea Drilling Capabilities
The successful identification of the Kaiping South reserves also highlights the rapid technological progress made by China in deep-sea exploration. The use of advanced 3D seismic imaging and high-precision drilling techniques allowed CNOOC to reach and analyze deep-lying reserves with high geological accuracy.
The operation is part of a broader shift in China’s energy portfolio, which increasingly focuses on offshore and ultra-deepwater resources to reduce reliance on foreign imports and enhance resilience against global energy market fluctuations.
CNOOC has stated that the discovery “once again demonstrates the broad prospects for exploration in the Pearl River Mouth Basin.” The company’s continued investment in offshore exploration aligns with national objectives set out in recent Five-Year Plans, which prioritize domestic production and the development of frontier technologies.
