EP 1375817 A1 20040102 - Underbalance drilling downhole choke
Title (en)
Underbalance drilling downhole choke
Title (de)
Drosselventil zum Unterdruckbohren
Title (fr)
Soupape d'étranglement de forage en sous-pression
Publication
Application
Priority
EP 02291569 A 20020624
Abstract (en)
A method for underbalance drilling in a reservoir comprises operating a variable aperture of a downhole choke located at a downhole extremity of a drill string. The variable aperture allows to control a pressure differential between a drilling fluid pumped down the drill string from surface and flowing into the variable aperture of the choke, and the drilling fluid flowing out of the variable aperture, in order to achieve a negative differential pressure between a reservoir pressure and a bottom hole pressure at the downhole extremity of the drill string. <IMAGE>
IPC 1-7
IPC 8 full level
E21B 21/08 (2006.01); E21B 21/10 (2006.01); E21B 21/00 (2006.01)
CPC (source: EP US)
E21B 21/085 (2020.05 - EP US); E21B 21/10 (2013.01 - EP)
Citation (applicant)
WO 0206634 A1 20020124 - SCHLUMBERGER TECHNOLOGY BV [NL], et al
Citation (search report)
- [X] US 6230824 B1 20010515 - PETERMAN CHARLES P [US], et al
- [X] US 5174392 A 19921229 - REINHARDT PAUL A [US]
- [A] US 5355967 A 19941018 - MUELLER MARK D [US], et al
- [A] WO 0050731 A1 20000831 - WEATHERFORD LAMB [US], et al
- [A] WO 0004269 A2 20000127 - DEEP VISION LLC [US]
- [A] US 4630691 A 19861223 - HOOPER DAVID W [US]
- [A] WO 0214649 A1 20020221 - TESCO CORP [CA], et al
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
EP 1375817 A1 20040102; EP 1375817 B1 20060308; AT E319911 T1 20060315; DE 60209669 D1 20060504
DOCDB simple family (application)
EP 02291569 A 20020624; AT 02291569 T 20020624; DE 60209669 T 20020624