China's deep-sea gas field Shenhai-1, or Deep Sea No.1, conducted its first deep-sea pipeline cleaning for the first time on Sunday since it commenced operation in 2021.

It was also China's first time carrying out the maneuver in ultra-deep waters, which will help improve the nation's technology and maintenance skills and pave the way to developing deep-sea gas fields with higher efficiency.

The production system was installed 1,500 meters below the water surface, connected to the platform over the sea through pipelines.

The pipelines can be blocked or eroded after long-term operation, requiring cleaning to solve the problem. Over 100 kilometers of pipeline were cleaned on Sunday.

Experts said cleaning the pipeline in ultra-deep water has far more risks than in shallow water, as the pipelines can sometimes be frozen.