| (19) |
 |
|
(11) |
EP 0 346 961 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
15.05.1991 Bulletin 1991/20 |
| (43) |
Date of publication A2: |
|
20.12.1989 Bulletin 1989/51 |
| (22) |
Date of filing: 25.05.1989 |
|
|
| (84) |
Designated Contracting States: |
|
DE FR GB IT NL |
| (30) |
Priority: |
14.06.1988 GB 8814004
|
| (71) |
Applicant: SHELL INTERNATIONALE RESEARCH
MAATSCHAPPIJ B.V. |
|
NL-2596 HR Den Haag (NL) |
|
| (72) |
Inventors: |
|
- Van Kleef, Rudolfus Petrus Antonius Robertus
NL-2288 GD Rijswijk (NL)
- Lohbeck, Wilhelmus Christianus Maria
NL-2288 GD Rijswijk (NL)
|
|
| |
|
| (54) |
Method and apparatus for placing a cement lining in a borehole |
(57) A cement lining is placed in a borehole using a cementing apparatus including a centralized
stinger (6) which is suspended from a cement injection tubing (5). In use a cement
slurry is introduced into the annular space (3) surrounding the tubing and stinger
and after subsequently filling the interior of the tubing and stinger with mud the
apparatus is pulled thereby leaving in the borehole a cement plug with an open or
soft core. The centralization of the stinger ensures that after hardening of the cement
a cement layer of a constant thickness is created alongside the borehole wall (1).