Peng Guangrong, a geologist at CNOOC's Shenzhen branch, noted that 60 percent of the world's newly discovered oil and gas reserves have come from deep layers. With abundant resources and a low level of exploration, deep to ultra-deep layers are expected to drive future growth in oil and gas reserves and production.

China's oil and gas exploration in the eastern South China Sea has seen consecutive breakthroughs, with oilfields exceeding 100 million tonnes in reserves discovered for two straight years, said CNOOC's CEO Zhou Xinhuai.