Editor’s note: On November 17, the Mengxiang (Dream), China’s first ocean drilling vessel, officially entered service. From project approval and feasibility work through to completion and entry into service, the organizations involved spent ten years breaking through numerous core key technologies to develop an ocean drilling vessel with fully independent intellectual property rights. This series from CSSC reports on how the participating organizations built the vessel and advanced science and technology innovation.
The Mengxiang is intended to promote high-level opening up, expand international ocean cooperation and serve scientists worldwide in exploring the mysteries of the earth. That meant developing an ocean drilling vessel that scientists around the world can afford to use, according to Zhang Haibin, deputy chief engineer of the 708 Research Institute of China State Shipbuilding Corporation (CSSC) and chief designer of the Mengxiang ocean drilling vessel. The challenge was to control construction and operating costs while still meeting the requirement for multiple functions.
How were both goals achieved?
Reducing the design gross tonnage made the vessel cheaper to build. The control target was 33,000 gross tonnage, and the design gross tonnage achieved is more than 40% lower than comparable international ocean drilling vessels.
Reducing operating energy consumption made the vessel cheaper to run. Through a closed-loop power grid design based on energy storage technology, a latest-generation hydraulic lifting drilling rig and extensive use of innovative energy-saving technologies, the ship’s overall energy consumption was cut by 15%, and operating costs are more than 40% lower than comparable vessels.
Four drilling modes plus three coring methods allow the vessel to cover multiple types of operations. The four drilling modes are conventional riser drilling, conventional riserless drilling, light riser drilling and riserless closed-loop mud circulation. The three coring methods are drill-string tripping, wireline coring and gas-lift reverse circulation coring. Together they allow the vessel to handle ocean scientific drilling, deep-sea oil and gas exploration, and natural gas hydrate exploration and trial production.
Whole-process automation raised efficiency. The vessel’s hydraulic lifting drilling rig combines oil and gas exploration and core drilling functions, and an automated core transfer and storage system provides fully automated operations from core collection through transfer to storage, raising deep-sea hard-rock coring efficiency by 40%.
