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Patent Searching and Data


Title:
DOWNHOLE STRING FOR DRILLING THROUGH A LOW PRESSURE ZONE
Document Type and Number:
WIPO Patent Application WO/2015/177122
Kind Code:
A3
Abstract:
The present invention relates to a downhole string (1) for drilling through a low pressure zone (Zlow) in a formation (45) in a well (3), comprising a drawdown casing (2) having a first end (4) closest to a top (5) of the well and a second end (6), and an operational tool (8) connected to the second end of the drawdown casing, wherein the downhole string further comprises an annular barrier (10) having an expandable metal sleeve (11) surrounding the drawdown casing, each end of the expandable metal sleeve being connected with the drawdown casing, the expandable metal sleeve being adapted to contact a wall (16) of a borehole (17) or another casing so that the drawdown casing can rotate and slide in relation to the annular barrier after expansion of the expandable sleeve. Furthermore, the present invention relates to a downhole system and to a downhole method.

Inventors:
HAZEL PAUL (GB)
Application Number:
PCT/EP2015/060962
Publication Date:
May 19, 2016
Filing Date:
May 19, 2015
Export Citation:
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Assignee:
WELLTEC AS (DK)
International Classes:
E21B33/127; E21B7/20; E21B17/05; E21B21/00; E21B33/13; E21B43/10
Domestic Patent References:
WO2013011293A22013-01-24
WO2010136806A22010-12-02
Foreign References:
US20060185857A12006-08-24
EP2305947A22011-04-06
US20060016623A12006-01-26
US20080264690A12008-10-30
Other References:
See also references of EP 3146144A2
Attorney, Agent or Firm:
HOFFMANN DRAGSTED A/S (KĂžbenhavn V, DK)
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