In order to meet the needs of seabed solid mineral resources and seabed geological environment investigation, this paper studies a set of seabed drilling and grab integrated sampling system suitable for deep sea. The system is equipped with seabed rock sample drilling system and hydraulic mechanical grab equipment, which can not only drill seabed columnar core samples, but also grab massive rock samples on the seabed surface, and realize a variety of sampling functions at the bottom of the pedestal.
Marine sediment cores are essential samples for research in marine geology, marine biology, paleoenvironmental science, and deep-sea mineral resource development. Due to the ocean has been transported by rivers, heavy metals transported by the atmosphere, remains of marine organisms, and isotopic fractionation between seawater and the atmosphere, the deep-sea cores are less disturbed by the outside environment and can provide a more continuous record, which contains extremely rich information. The most important material for understanding the history of Earth's climate change and marine biogeographical distribution information, and deep-sea surface sediments are key samples for studying contemporary provenance and sediment transport characteristics, as well as microbial research.
At present, the sampling of marine core and surface samples mainly includes gravity corers, vibration samplers, deep-sea drilling rigs, and clam samplers. Gravity corers and vibratory samplers are only used in very soft or loose geological conditions, and the coring depth of these methods is also limited to the length of their single core barrel. It has its limitations to extend the coring depth by lengthening the core barrel. Deep-sea drilling rigs are often too bulky, clam-type samplers are mostly used in lakes, rivers and shallow seas, and deep-sea applications are less. The 3000 meters deep-sea drilling rig developed by India weighs 13 tons and can obtain core samples with a diameter of 63.5 mm and a length of 100 meters (Ross E. Murray, 2010). The 2500-meter drilling rig (BGS) developed by the British Geological Survey can obtain 5-meter-long cores and integrate a camera monitoring system (Sven Petersen, 2005). The BMS-2 (Benthic Multicoring System) developed by Williamson & Associates in the United States successfully drilled 4.4 m core samples in the waters near the Ogasawara Islands in the East China Sea (5815 m water depth) in 2006 (Freudenthal T, 2009). PROD (Portable Remotely Operated Drill) is a multifunctional seabed drilling and geotechnical testing system developed by BENTHIC in Australia, while in hard formations rotary drilling corers are used (Kelleher P, 2008). The MeBo (Meeresboden - Bohrgerät) seabed drilling rig developed in Germany is suitable for water depths up to 2000m, with a single drilling depth of 3.5m (Freudenthal T, 2010). The American Williamson & Associates company delivered the ACS (Automatic Coring System) seabed automatic coring system to the National Institute of Ocean Technology of India in February 2010. RE, 2010). The ROVDrill developed by HELIX CANYON OFFSHORE in the United States is a new type of seabed drilling rig system combined with ROV technology, which has the functions of drilling and coring and in-situ testing (Spencer A, 2008). To sum up, there is almost no lightweight system that can simultaneously obtain serialized columnar cores and surface sediments at the same point. More comprehensive samples can realize the intuitive and accurate comparison and analysis of seabed rock formations and surface rocks. Therefore, the system provides technical and equipment support for marine scientific exploration.
