Six governments claim parts of the 3.5 million-square-kilometer South China Sea. They are Brunei, China, Malaysia, the Philippines, Taiwan and Vietnam. The disputes have increased partly because of claims to undersea gas and oil. The U.S. Energy Information Agency estimates that 11 billion barrels of oil and large amounts of natural gas are under the sea. China claims about 90 percent of the sea. It has built the most landforms in the sea upsetting countries that also have claims. India and Spain have worked with Vietnam to find undersea oil since 2016. The Philippines worked with U.S.-based Forum Energy to explore for oil in 2012. And in 2014, the oil company Shell and a Malaysian company found natural gas. In the recent announcement, SK Innovation said it drilled for oil in December and found a supply that, it said, tested up to 3,750 barrels of oil per day. The company said it plans additional wells to find out more about the supply. The company has been exploring the area since 2015 in partnership with the state-owned China National Offshore Oil Corporation.
