Abstract: A mining riser pipe is extended from above water toward a water bottom containing water bottom resources, and a lower portion of an insertion pipe connected to a lower portion of the mining riser pipe is inserted into the water bottom. A liquid is supplied into the insertion pipe and a rotation shaft extends axially inside both of pipes is rotated to rotate stirring blades attached to a lower portion of the rotation shaft inside the insertion pipe, thereby drilling and dissolving mud S inside the insertion pipe into a slurry form is raised to an upper portion of the insertion pipe by a stirring flow generated by the rotation of the stirring blades, and the raised mud is lifted above the water through the mining riser pipe by lifting force.

Abstract: A mining riser pipe is extended toward a water bottom, and a lower portion of an insertion pipe connected to a lower portion of the mining riser pipe is inserted into the water bottom. A liquid is supplied into the insertion pipe, and a rotation shaft extends inside both pipes and stirring blades attached to a lower portion of the rotation shaft are rotated inside the insertion pipe, thereby drilling and dissolving mud inside the insertion pipe into a slurry. Then, the mud S is raised to an upper portion of the insertion pipe by a stirring flow generated by the stirring blades, and the raised mud slurry is lifted above the water through the mining riser pipe 2, and a rotation speed of the stirring blades is lower in an initial process at an early stage of the drilling than in a subsequent process.

Abstract: A method for recovering rare-earth mud including steps of: (A) penetrating a mud gathering pipe into a layer containing rare-earth mud under the seafloor, (B) preparing a slurry containing a rare earth by loosening rare-earth mud in the mud gathering pipe, and (C) transferring the slurry through a mud raising pipe. A rare-earth mud recovery system including: a mud gathering pipe configured to penetrate into a layer containing rare-earth mud under a seafloor; a stirring device configured to loosen rare-earth mud in the mud gathering pipe; and a mud raising pipe connected to the mud gathering pipe.

Abstract: A lock plug (7A) is inserted into a plug installation position of an insertion hole (5a) of a tool stem (5) connected to a drill string (10), and when a fluid has flowed to the insertion hole (5a), a stopper (62) protrudes radially outward from a tool body (6) and is locked to a subsea wellhead (4) and an internal stopper (66) protrudes radially inward from the tool body (6) and is locked to the tool stem (5) in a lock state. An unlock plug is inserted into the plug installation position of the insertion hole (5a), and when the fluid has flowed into the insertion hole (5a), the stopper (62) is separated from the subsea wellhead (4) and the internal stopper (66) is separated from the tool stem (5) to release the lock state.

Abstract: The submarine drilling support system includes a first guide support part that has a ring shape, has a plurality of rollers of which roller axes are directed to a horizontal direction and is arranged along a circumferential direction going around a rotation support axis parallel to a vertical direction, and is provided to allow the drill pipe to be inserted through in the vertical direction; and a first rotation holding part that is configured to support the first guide support part so as to be rotatable in the circumferential direction. The pluralities of rollers are adjacent to each other in the circumferential direction and are arranged in a state where the drill pipe is able to insert through a space surrounded by the plurality of rollers.

Abstract: A lock plug (7A) is inserted into a plug installation position of an insertion hole (5a) of a tool stem (5) connected to a drill string (10), and when a fluid has flowed to the insertion hole (5a), a stopper (62) protrudes radially outward from a tool body (6) and is locked to a subsea wellhead (4) and an internal stopper (66) protrudes radially inward from the tool body (6) and is locked to the tool stem (5) in a lock state. An unlock plug is inserted into the plug installation position of the insertion hole (5a), and when the fluid has flowed into the insertion hole (5a), the stopper (62) is separated from the subsea wellhead (4) and the internal stopper (66) is separated from the tool stem (5) to release the lock state.

Abstract: The submarine drilling support system includes a first guide support part that has a ring shape, has a plurality of rollers of which roller axes are directed to a horizontal direction and is arranged along a circumferential direction going around a rotation support axis parallel to a vertical direction, and is provided to allow the drill pipe to be inserted through in the vertical direction; and a first rotation holding part that is configured to support the first guide support part so as to be rotatable in the circumferential direction. The pluralities of rollers are adjacent to each other in the circumferential direction and are arranged in a state where the drill pipe is able to insert through a space surrounded by the plurality of rollers.

Abstract: Disclosed herein are a crustal core sampler, by which a crustal core sample can be cored in a state coated with a flow-able coating material free of any contamination, and a method of coring a core sample using this crustal core sampler. The crustal core sampler comprises a drilling mechanism and a barrel, wherein the barrel is equipped with a flow-able coating material-ejecting mechanism, and a columnar crustal core portion is coated with a flow-able coating material. Alternatively, the crustal core sampler is constructed by a drill pipe and an inner barrel, wherein the inner barrel is equipped with an inner barrel body, a core elevator, a channel-forming member for forming a flow-able coating material-running channel and flow-able coating material-ejecting openings, and a columnar crustal core portion is coated with a flow-able coating material.

Abstract: Disclosed herein are a crustal core sampler, by which a crustal core sample can be cored in a state coated with a flow-able coating material free of any contamination, and a method of coring a core sample using this crustal core sampler. The crustal core sampler comprises a drilling mechanism and a barrel, wherein the barrel is equipped with a flow-able coating material-ejecting mechanism, and a columnar crustal core portion is coated with a flow-able coating material. Alternatively, the crustal core sampler is constructed by a drill pipe and an inner barrel, wherein the inner barrel is equipped with an inner barrel body, a core elevator, a channel-forming member for forming a flow-able coating material-running channel and flow-able coating material-ejecting openings, and a columnar crustal core portion is coated with a flow-able coating material.