EP 0248615 A3 19881130 - IMPROVEMENTS IN DRILLING APPARATUS

Title (en)

IMPROVEMENTS IN DRILLING APPARATUS

Publication

EP 0248615 A3 19881130 (EN)

Application

EP 87304811 A 19870601

Priority

GB 8613582 A 19860604

Abstract (en)

[origin: EP0248615A2] Drilling apparatus is coated on selected surfaces with PTFE. In the drawing is shown an example of the application of the invention to a core barrel assembly. An outer core barrel l0 and an inner core barrel ll are shown which are normally in sections. At the lower end of the outer core barrel there is attached a core catcher sub l3. At the lower end of the inner barrel ll is attached an inner barrel breaker sub l4 and below that a core catcher l5. A core bit l6 is attached to the lower end of the outer barrel. Parts are shown coated with PTFE by thick lines, e.g. the inner surface l8 of the inner barrel ll, the outer surface l9 of the inner barrel and the inner surface 20 of the outer barrel l0. The outer surface 2l of outer barrel l0 may also be coated for example, and the surface 22 of the drill bit, the inner surface 23 of the core catcher and the inner surface 24 of the inner barrel breaker sub.

IPC 1-7

E21B 25/00; E21B 25/12; E21B 10/00; E21B 10/02; E21B 17/00; E21B 21/00

IPC 8 full level

E21B 10/00 (2006.01); E21B 10/02 (2006.01); E21B 17/00 (2006.01); E21B 21/00 (2006.01); E21B 25/00 (2006.01); E21B 25/12 (2006.01)

CPC (source: EP)

E21B 10/00 (2013.01); E21B 10/02 (2013.01); E21B 17/00 (2013.01); E21B 25/00 (2013.01); E21B 25/12 (2013.01)

Citation (search report)

[X] DD 123550 B
[X] EP 0190092 A2 19860806 - MANNESMANN AG [DE]
[X] US 4365678 A 19821228 - FITCH JOHN L
[X] FR 2514097 A1 19830408 - GOODRICH CO B F [US]
[A] US 3990751 A 19761109 - MURDOCH HENRY W
[A] BE 886911 A 19810416 - DIAMANT BOART SA
[Y] WORLD OIL, vol. 200, no. 5, April 1985, pages 83-86,88,90, Houston, Texas, US; A. PARK: "Coring; part 2 - core barrel types and uses"
[X] SOVIET INVENTIONS ILLUSTRATED, week 21, 6th July 1983, section H01 A97 Q49, no. 51139 K/21, Derwent Publications Ltd, London, GB; & SU-A-941 542 (VNIPINEFTEPROMKHIM) 17-07-1982

Designated contracting state (EPC)

AT BE CH DE ES FR GB GR IT LI LU NL SE

DOCDB simple family (publication)

EP 0248615 A2 19871209; EP 0248615 A3 19881130

DOCDB simple family (application)

EP 87304811 A 19870601