公开(公告)号：US11230890B2

公开(公告)日：2022-01-25

申请号：US16480631

申请日：2017-12-12

申请人： THE UNIVERSITY OF TOKYO ,  TOHOKU UNIVERSITY ,  INPEX DRILLING CO., LTD.

发明人： Shigemi Naganawa ,  Noriyoshi Tuchiya ,  Kuniaki Shimada

IPC分类号： E21B10/60 ,  E21B7/00 ,  E21B10/42 ,  E21B10/61 ,  E21B10/08 ,  E21B10/54

摘要： A well drilling bit for drilling bedrocks includes a columnar bit body, and a drilling fluid flow path formed in the bit body to wash away drilled cuttings from a bottomhole and/or a periphery of the bit body. The flow path is provided with a venturi mechanism including a venturi tube having a reduced-diameter portion where a cross sectional area is reduced and capable of generating a decompression region around a tip of the bit body, the decompression region being more decompressed than a surrounding by the Venturi effect.

公开(公告)号：US11326433B2

公开(公告)日：2022-05-10

申请号：US16967035

申请日：2019-01-31

申请人： NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY ,  THE UNIVERSITY OF TOKYO ,  TOHOKU UNIVERSITY ,  JMC GEOTHERMAL ENGINEERING CO., LTD. ,  INPEX DRILLING CO., LTD.

发明人： Hiroshi Asanuma ,  Shigemi Naganawa ,  Noriyoshi Tsuchiya ,  Tatsuya Kajiwara ,  Kuniaki Shimada

IPC分类号： E21B43/26 ,  E21B33/12 ,  E21B34/16

摘要： A fracturing method, to cause a crack in bedrock, includes installing a depressurizing device in a well in the bedrock, and depressurizing the inside of the well with the installed depressurizing device. The installing step includes installing, in the well, a connecting pipe, which is connected to the depressurizing device, and a packer, which is attached to the connecting pipe, and the depressurizing step includes shutting off a gap between the well and the connecting pipe, with the packer, and depressurizing a region in the well below the packer, with the depressurizing device.

公开(公告)号：US10801299B2

公开(公告)日：2020-10-13

申请号：US16062251

申请日：2016-12-09

申请人： TEISEKI DRILLING CO., LTD. ,  THE UNIVERSITY OF TOKYO

发明人： Kuniaki Shimada ,  Shigemi Naganawa ,  Seiki Horimoto

IPC分类号： E21B33/12 ,  E21B34/06 ,  E21B41/00 ,  E21B43/10 ,  E21B36/00 ,  F24T10/00

摘要： A packer connected to a casing pipe, the packer including a connecting tube made of metal and connected to the casing pipe, and a packer part made of metal and attached around the connecting tube. The packer part has a hollow part inside. A sealed liquid that thermally expands is sealed in the hollow part. An outer peripheral wall of the packer part includes an expansive part that protrudingly deforms outward with the thermal expansion of the sealed liquid.