Title:
DRILLING PROCESS OF PRESSURE-PRESERVING CABLE CORE DRILLING MACHINE FOR SUBSEA NATURAL GAS HYDRATES
Document Type and Number:
WIPO Patent Application WO/2020/034643
Kind Code:
A1
Abstract:
A drilling process of a pressure-preserving cable core drilling machine for subsea natural gas hydrates, comprising the following steps: 1) drilling down; 2) core drilling by suction and pure-pressing for soft formation, or core drilling by suction and rotation for medium hard formation, or core drilling by pumping and direct-circulation rotation for hard formation; 3) core drawing; 4) salvaging by a pressure-preserving cable core-withdrawing inner pipe (18); 5) screwing a pressure-preserving seal cover (15) on the pressure-preserving cable core-withdrawing inner pipe, and sending same to a drilling machine pipe storage frame for storage; 6) punching before connecting a drill rod (14); 7) grasping the pressure-preserving cable core-withdrawing inner pipe, after being emptied, from the drilling machine pipe storage frame and unscrewing the pressure-preserving seal cover; 8) lowering the pressure-preserving cable core-withdrawing inner pipe; 9) connecting the drill rod; 10) punching after connecting the drill rod; 11) repeating steps 2)-10) until core drilling to a given hole depth; 12) recovering the drill rod and the drilling tool; and 13) recovering the drilling machine. Said drilling process uses a subsea pressure-preserving cable core drilling machine to perform pressure-preserving core drilling on subsea natural gas hydrates, having advantages of high drilling efficiency, high coring rate, good pressure-preserving performance, and high degree of automation, etc.
Inventors:
WAN BUYAN (CN)
JIN YONGPING (CN)
HUNAG XIAOJUN (CN)
WANG JIALIANG (CN)
JIN YONGPING (CN)
HUNAG XIAOJUN (CN)
WANG JIALIANG (CN)
Application Number:
PCT/CN2019/080690
Publication Date:
February 20, 2020
Filing Date:
March 30, 2019
Export Citation:
Assignee:
UNIV HUNAN SCIENCE & TECHNOLOGY (CN)
International Classes:
E21B25/00; E21B21/00; E21B21/10; E21B25/18
Domestic Patent References:
| WO2018056274A1 | 2018-03-29 |
Foreign References:
| CN108979577A | 2018-12-11 | |||
| CN105239947A | 2016-01-13 | |||
| CN102606074A | 2012-07-25 | |||
| CN107288565A | 2017-10-24 | |||
| DE102005006039A1 | 2006-08-10 |
Other References:
See also references of EP 3640427A4
Attorney, Agent or Firm:
XIANGTAN HUIZHI PATENT AGENCY (GENERAL PARTNERSHIP) (CN)
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