New 16,172-foot deep-sea drilling milestone places China alongside US, Japan

China’s Mengxiang (Dream) ocean drilling vessel has reached a new deep-sea drilling milestone after recovering basalt from the South China Sea basin, China’s Ministry of Natural Resources said Monday. The vessel completed a 30-day scientific drilling trial and returned to Guangzhou, Guangdong Province, after drilling to a maximum depth of 16,172 feet (4,929.17 meters).

During the mission, Mengxiang achieved a maximum total water depth of 4,929.17 meters (16,172 feet) and drilled to a maximum penetration of 864.77 meters (2,837 feet). The results set a new national record for independently conducted deep-sea drilling in China.

The mission focused on testing the vessel and its scientific drilling systems in ultra-deep water. It also allowed researchers to collect geological material from the ocean basin and evaluate equipment under demanding conditions.

China has now joined the U.S. and Japan as the third country to retrieve hard-rock samples from a deep-sea ocean basin using a drilling vessel.

Basalt core recovered from seafloor

Researchers used self-developed rotary coring tools to recover a 4.27-meter-long (14-foot-long) basalt core. The sample provides direct material from the deep-ocean crust for geological studies.

The expedition also established a coring system designed to meet standards set by the International Ocean Discovery Program (IODP). During several operations, core-recovery rates exceeded 100 percent. The team said its coring efficiency, sample quality, and operational stability reached advanced IODP benchmarks.

The ability to recover long and intact rock sections is important for researchers studying the structure and history of the ocean floor. The cores can preserve physical and chemical evidence of geological processes that occurred over long periods.

China's Mengxiang (Dream) ocean drilling vessel has set a national record in deep-sea drilling, elevating its capability to the 5,000-meter level, after obtaining basalt samples from the South China Sea basin, the Ministry of Natural Resources said on Monday. pic.twitter.com/4oPIzhrKi0

— People's Daily, China (@PDChina) September 28, 2026

ROVs operate at 13,123 feet

The mission also tested underwater robotic systems during extended operations. For the first time, ship-borne remotely operated vehicles (ROVs) carried out long-duration, high-intensity coordinated work during the drilling mission.

Two ROVs accumulated more than 358 working hours at depths of 4,000 meters (13,123 feet). One continuous operation lasted as long as 103 hours. The performance was described as reaching international advanced levels.

The team also developed a risk-prevention and emergency-response system for ultra-deep-water drilling. Together, these capabilities demonstrate China’s ability to manage a complete scientific drilling workflow in extreme water depths.

Core samples could reveal South China Sea history

For the first time, the team processed and analyzed the recovered cores according to IODP procedures. The work covered collection, documentation, description, sectioning, scanning, sampling, testing and archiving.

The cruise produced a large volume of rock cores and scientific data. Researchers expect the material to help address questions surrounding seafloor spreading and the geological development of the South China Sea.

The samples could also provide evidence about how the basin formed and evolved. Beyond geological research, the results may support studies of the region’s paleo-environmental history and contribute to research related to energy exploration and development in ultra-deep waters.

Source: https://interestingengineering.com/energy/china-drill-ship-reaches-16000-feet-deep