US 12,084,948 B2
Method for recovering rare-earth mud, and recovery system
Eigou Miyazaki, Yokosuka (JP); Yoshihisa Kawamura, Yokosuka (JP); Ikuo Sawada, Yokosuka (JP); Masanori Kyo, Yokosuka (JP); Mikito Furuichi, Yokosuka (JP); Keita Akiyama, Yokosuka (JP); and Yasuhiro Namba, Yokosuka (JP)
Assigned to Japan Agency for Marine-Earth Science and Technology, Kanagawa (JP)
Appl. No. 17/904,804
Filed by Japan Agency for Marine-Earth Science and Technology, Kanagawa (JP)
PCT Filed Feb. 26, 2021, PCT No. PCT/JP2021/007447
§ 371(c)(1), (2) Date Aug. 23, 2022,
PCT Pub. No. WO2021/172540, PCT Pub. Date Sep. 2, 2021.
Claims priority of application No. 2020-033838 (JP), filed on Feb. 28, 2020.
Prior Publication US 2023/0112110 A1, Apr. 13, 2023
Int. Cl. E21B 43/01 (2006.01); E21B 43/29 (2006.01)
CPC E21B 43/01 (2013.01) [E21B 43/29 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for recovering rare-earth mud comprising:
(A) inserting a mud gathering pipe into a layer containing rare-earth mud under a seafloor;
(B) preparing a slurry containing a rare earth by rotating a stirring device within the mud gathering pipe to loosen the rare-earth mud; and
(C) transferring the slurry through a mud raising pipe,
wherein the stirring device includes a drill pipe having a lower portion extending into the mud gathering pipe and an upper portion extending outside the mud gathering pipe,
wherein the mud raising pipe extends around the upper portion of the drill pipe to form a double pipe structure,
wherein the slurry is transferred by a circulating flow through an annulus part of the double pipe structure, that is formed between an outer surface of the drill pipe and an inner surface of the mud raising pipe, and
wherein the method further comprises directing a fluid from inside the drill pipe into the annulus part via an opening of the drill pipe that faces the inner surface of the mud raising pipe, to generate the circulating flow.