Experimental Research on the Process Parameters of a Novel Low-Load Drill Bit Used for 7000 m Bedrock Sampling Base on Manned Submersible

Due to the need for accurate exploration of deep-sea scientific research, drilling techniques by combining operational advantages Jiaolong manned submersible is considered one most feasible methods bedrock drilling. Based on deep sea cutting model and discrete element simulation, as well efficient design criterion, development a 7000 m electromechanical coring apparatus was carried out. The outstanding feature this technology that bit load produced drill pressure usually within range 100–400 N while recommended diamond 1–3 KN or even more. Therefore, searching bits can in extremely hard formations with minimal acceptable rates penetration rotary speed necessary step prove feasibility technology. A test has been designed constructed examine three types bits. results experiments show new low-load polycrystalline compact (PDC) highest length 138 mm/15 min under 300 250 rpm speed. Finally, field tests were used conduct verify model, which provides theoretical technical data use core sampling developed specifically submersible.