Photo taken on July 9, 2017 shows spraying of water at the trial mining site in the Shenhu area of the South China Sea. [Photo/Xinhua]

Chinese scientists this time invented a new technique to prevent sand from disrupting the exploration. Other adjustments were also made to ensure commercial explorations.

Environmental tests showed that there were no methane leaks. Neither did geological hazards occur.

China began research in combustible ice in 1998. The latest exploration showcased a number of breakthroughs.

"China is leading the world in combustible ice exploration, whether it is about theory, techniques, machinery, or engineering," said Ye Jianliang, director of Guangzhou Marine Geological Bureau.

"The trial will have a big impact on the world's energy sector," he said.

Li said his bureau will double the efforts on research to prepare for combustible ice's commercial production, with emphasis on ocean ecology protection and "green" exploitation of the new energy. Regulations on exploitation management and industrial policy are also being drawn up.