Title:
METHOD FOR REMOTELY TURNING OFF DOWNHOLE UNIT FROM THE SURFACE APPLICABLE TO ROTARY STEERING SYSTEM
Document Type and Number:
WIPO Patent Application WO/2021/238898
Kind Code:
A1
Abstract:
A method for remotely turning off a downhole unit from the surface applicable to a rotary steering system. The method comprises the following steps: a, calculating a difference in pressure P1 in front of and behind a water hole of a drilling bit; b, calculating an extended-range loss ΔP; c, calculating a pressure P2 at a vertical pipe after a downstream device is activated; d, according to a pressure balance relationship, a pressure drop of a throttle valve of the downstream device also being P2, calculating an opened area S1 of the throttle valve of the downstream device; and e, according to a relationship between the degree of opening of the throttle valve and the opened area S1 of the throttle valve, adjusting the throttle valve to a calculated degree of opening, such that a shunt flow automatically reaches a configured shunt ratio; and automatically determining, according to a measured flow change, a functional block to be cut off, and turning off a downhole unit. The method enables an entire rotary steering system to perform self-protection and continuous operation, and reduces, when the rotary steering system is abnormal, the frequency of pulling out a drilling bit for inspection, improving efficiency of drilling operations, and reducing costs.
Inventors:
BAI JING (CN)
ZHANG JICHUAN (CN)
LU DENGYUN (CN)
LI LEI (CN)
HUANG CHONGJUN (CN)
JIA LICHUN (CN)
LIAO CHONG (CN)
HAN LIEXIANG (CN)
ZHANG DEJUN (CN)
TANG GUI (CN)
ZHANG JICHUAN (CN)
LU DENGYUN (CN)
LI LEI (CN)
HUANG CHONGJUN (CN)
JIA LICHUN (CN)
LIAO CHONG (CN)
HAN LIEXIANG (CN)
ZHANG DEJUN (CN)
TANG GUI (CN)
Application Number:
PCT/CN2021/095724
Publication Date:
December 02, 2021
Filing Date:
May 25, 2021
Export Citation:
Assignee:
CHINA NAT PETROLEUM CORP (CN)
CNPC CHUANQING DRILLING ENG CO (CN)
CNPC CHUANQING DRILLING ENG CO (CN)
International Classes:
E21B21/08; E21B7/04; E21B21/10; E21B44/00
Foreign References:
| CN111502546A | 2020-08-07 | |||
| CN203603892U | 2014-05-21 | |||
| CN102022082A | 2011-04-20 | |||
| US20120067593A1 | 2012-03-22 | |||
| CN105332687A | 2016-02-17 | |||
| CN107044263A | 2017-08-15 |
Attorney, Agent or Firm:
CHENGDU TIANJIA PATENT OFFICE (GENERAL PARTNERSHIP) (CN)
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