(19)
(11) EP 0 647 767 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
02.11.1995 Bulletin 1995/44

(43) Date of publication A2:
12.04.1995 Bulletin 1995/15

(21) Application number: 94306792.6

(22) Date of filing: 16.09.1994
(51) International Patent Classification (IPC)6: E21B 43/119
(84) Designated Contracting States:
DE DK FR GB IT NL

(30) Priority: 12.10.1993 US 134730

(71) Applicants:
  • Anadrill International SA
    Panama City (PA)

    DE DK GB IT NL 
  • SERVICES PETROLIERS SCHLUMBERGER
    F-75007 Paris (FR)

    FR 

(72) Inventor:
  • Decker, David P.
    Sugar Land, Texas 77479 (US)

(74) Representative: Stoole, Brian David et al
Schlumberger plc, Patent Department, 1 Kingsway, First Floor
London WC2B 6XH
London WC2B 6XH (GB)


(56) References cited: : 
   
       


    (54) Methods for conducting tubing-conveyed perforating operations in well bores


    (57) In the representative mode for practicing the invention disclosed herein for accurately positioning tubing-conveyed well bore apparatus in a well bore a retrievable MWD tool (32) having a radiation detector is positioned in the lower portion of a tubing string (12) carrying a tubing-conveyed perforator (17) carrying shaped explosive charges. Once the tubing string has been lowered into a well bore, the MWD tool is operated for transmitting signals which are representative of the radioactive characteristics of either a radioactive marker at a known depth or the formations adjacent to the MWD tool. The signals are correlated for determining the location of the tubing-conveyed perforator within the well bore. The correlated data is used for adjusting the tubing string so as to accurately position the tubing-conveyed perforator at a desired depth location.






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