Title:
坑井掘削用ビット及びそれを用いた坑井掘削方法
Document Type and Number:
Japanese Patent JP6786069
Kind Code:
B2
Abstract:
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.
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Inventors:
Naganawa Nami
Noriyoshi Tsuchiya
Kuniaki Shimada
Noriyoshi Tsuchiya
Kuniaki Shimada
Application Number:
JP2017012284A
Publication Date:
November 18, 2020
Filing Date:
January 26, 2017
Export Citation:
Assignee:
National University Corporation Tokyo University
Tohoku University
Teishi Ishii Industry Co., Ltd.
Tohoku University
Teishi Ishii Industry Co., Ltd.
International Classes:
E21B10/60; E21B10/18
Domestic Patent References:
| JP2014177810A | ||||
| JP55108592A |
Foreign References:
| US20090279966 | ||||
| US4303137 |
Attorney, Agent or Firm:
Yasuhiko
Shinjo Castle Shigeki
Shinjo Castle Shigeki