China just discovered a major gas field in South China Sea – how will it affect the disputed zone?

New find, described as world’s first ‘ultra-shallow gas field in ultra-deep waters’, estimated to contain more than 100 billion cubic metres of natural gas

China has found a major gas field in the South China Sea, a discovery that could significantly influence the region’s complex geopolitical landscape.

This new find, described as the world’s first “ultra-shallow gas field in ultra-deep waters”, is estimated to contain more than 100 billion cubic metres (bcm) of natural gas, according to China’s state media.

The announcement was made by the China National Offshore Oil Corporation (CNOOC) in June, and the discovery has now been officially reviewed and registered by state authorities.

While the exact location of Lingshui 36-1 has not been disclosed, it is reportedly situated in waters southeast of Hainan, China’s southernmost island province, according to CNOOC. It has an average water depth of around 1,500m.

“The main gas-bearing play is the Ledong Formation of Quaternary, with an average burial depth of 210m,” CNOOC said in June. “The field has been tested to produce over 10mcm/day of open flow natural gas.”

The discovery adds to China’s already substantial reserves of gas in the South China Sea, which, together with other offshore fields, have now surpassed the trillion-cubic-metres mark.

However, the South China Sea, known for its rich deposits of hydrocarbons, has also been a focal point of intense territorial disputes involving several countries.

China’s claim to almost the entirety of the South China Sea, demarcated by the so-called “nine-dash line”, overlaps those of Vietnam, the Philippines, Malaysia, Brunei, and Taiwan.

Map shows exploration and development blocks in the South China Sea by different countries. Hainan province is seen here as the large island off China surrounded by its yellow blocks (World Bank/EIA)

Disputes and tensions often rise over each other’s oil and gas exploration and development attempts in the contested waters. The discovery of such a large gas field could potentially exacerbate existing tensions and complicate diplomatic relations among these nations.

The South China Sea is still underexplored because of these territorial disputes. Most discovered oil and gas fields are in uncontested areas, close to the shorelines. Approximately 3.6 billion barrels of petroleum and other liquids and 40.3 trillion cubic feet of gas in proved and probable reserves are in the South China Sea, according to Rystad, an independent research and business intelligence company.

The South China Sea is a crucial maritime region, not only for its economic resources but also for its strategic significance. The area is a major shipping route, with a significant portion of global trade passing through its waters. The new discovery by China could further assert its dominance in the region, potentially heightening friction with neighbouring countries who also have competing claims.

Vietnam and the Philippines, in particular, have been vocal in their opposition to China’s expansive claims and have engaged in their own exploratory activities in the disputed waters.

The presence of such a substantial gas field could lead to increased scrutiny and confrontations over resource exploitation and maritime boundaries.

Aside from the geopolitical ramifications, the discovery of Lingshui 36-1 also raises questions about environmental management and economic impact. The extraction of gas from ultra-deep waters presents significant technical challenges and environmental risks.

While shallow gas is abundant in the seabed, its precarious position makes it highly susceptible to dispersion caused by ocean currents. The formation of a commercially viable oil and gas field under such conditions was previously deemed impossible by experts.

How China plans to manage these challenges while ensuring environmental protection will be closely watched by the international community.