China News Service, Beijing, September 28 (Reporter Pang Wuji) The reporter learned from the China Geological Survey of the Ministry of Natural Resources of China on the 28th that recently, the "Dream" ocean drilling ship successfully drilled deep ocean basin basalt samples.
The "Dream" recently completed its ocean drilling test mission in the South China Sea and returned to Guangzhou. This is the "Dream"'s "first performance" in ocean scientific drilling. This voyage lasted 30 days and completed the drilling and coring tasks of two wells in the 4,100-meter water depth of the South China Sea. It successfully drilled basalt samples from the South China Sea basin and achieved many breakthroughs in the scientific research on the structural evolution of the South China Sea, the construction of a coring system, and the application of domestic core drilling equipment.
Recently, the "Dream" ocean drilling ship successfully drilled deep ocean basin basalt samples. The picture shows an aerial photo of the "Dream" drilling operation at night. Photo by Zhang Fatao
On this voyage, the "Dream" reached a maximum drilling depth of 4,929.17 meters and a maximum footage of 864.77 meters, setting a new record for China's independently implemented deepest drilling operation. The team used a self-developed rotary coring drill to successfully drill 4.27-meter basalt core samples, making China the third country in the world after the United States and Japan to use drilling ships to drill hard rock samples from deep ocean basins. At the same time, a coring operation system with the same level as international ocean drilling has been established. The coring rate in multiple operations has exceeded 100%, and the coring efficiency, quality and operation stability have reached the advanced level of international ocean drilling.
The team innovatively built a risk prevention, control and emergency response system for ultra-deep water and difficult well drilling. For the first time, long-term, high-intensity continuous collaborative operation of ship-borne deep-sea remotely operated vehicles (ROVs) was carried out. The two ROVs operated cumulatively for more than 358 hours under 4,000 meters of water, with a single continuous operation of up to 103 hours. The operating capabilities reached the international advanced level. For the first time, in accordance with international ocean drilling standards, the entire process of core sample collection, sorting, cataloging, sectioning, scanning, sampling, testing, and storage was completed on-site and multi-parameter processing and analysis was mastered, and the entire process of ultra-deep water ocean scientific drilling operations was mastered.
Recently, the "Dream" ocean drilling ship successfully drilled deep ocean basin basalt samples. The picture shows the on-site staff performing coring operations. Photo by Zhang Fatao
The voyage obtained a large number of valuable core samples and data. Preliminary research confirmed that there were multiple periods of large-scale volcanic eruptions after the transition of the South China Sea spreading ridge. It provided key evidence for solving core scientific issues such as the expansion of the South China Sea and is expected to revolutionize the scientific understanding of the formation and evolution of the South China Sea. At the same time, the team's drilling found a combination of oceanic red layers and green-dark green sedimentary interbeds, and encountered a sand-mud interbedded sedimentary structure dozens of meters thick at 813-864 meters below the seafloor. The strata were accompanied by obvious bioturbation and were rich in organic matter. This is the first time in China that such features have been found in deep strata with a water depth of over 4,000 meters in the South China Sea and far away from the land. It is of great significance to the study of the paleoenvironmental evolution of the South China Sea and the exploration and development of ultra-deep water energy resources.
This voyage was organized by the China Geological Survey of the Ministry of Natural Resources and implemented by the Guangzhou Marine Geological Survey. 170 scientific expedition team members from China Geological Survey, COSL, Peking University, CSSC, China University of Geosciences (Wuhan), Hainan University, Hainan Tropical Ocean Institute and other units participated. (over)
