(19)
(11) EP 0 403 025 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.05.1991 Bulletin 1991/22

(43) Date of publication A2:
19.12.1990 Bulletin 1990/51

(21) Application number: 90201532.0

(22) Date of filing: 13.06.1990
(51) International Patent Classification (IPC)5: E21B 33/138, E21B 21/12, E21B 7/20
(84) Designated Contracting States:
DE GB NL

(30) Priority: 14.06.1989 GB 8913647

(71) Applicant: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.
NL-2596 HR Den Haag (NL)

(72) Inventors:
  • Stewart, Robert Bruce
    NL-2288 GD Rijswijk (NL)
  • Van Kleef, Rudolfus Petrus Antonius Robertus
    NL-2288 GD Rijswijk (NL)
  • Lohbeck, Wilhelmus Christianus Maria
    NL-2288 GD Rijswijk (NL)


(56) References cited: : 
   
       


    (54) Method of drilling and lining a borehole


    (57) A method of drilling and lining a borehole (1) comprises the steps of drilling a borehole while a drilling fluid (13) is circulated through the bores (4, 5) of a multibore drill pipe string and an over-retarded cement slurry (12) is kept substantially stationary in a pipe-formation annulus (11) surrounding said string (2), whereupon after retrieval of the drilling assembly from the borehole the cement (12) is allowed to set to an annular lining of solid cement alongside the borehole wall (1).






    Search report