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(11) | EP 0 846 837 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Subterranean well bore casing milling apparatus |
| (57) Subterranean well bore casing milling apparatus comprising: a tubular anchor assembly
(22) having a top end portion and being coaxially and releasably securable in the
casing, said tubular anchor assembly including a tubular inner mandrel having an outer
side surface, a tubular slip carrier coaxially circumscribing the inner mandrel in
a radially outwardly spaced relationship therewith, the slip carrier having a circumferentially
spaced series of side wall slip windows therein and outwardly bounding an annular
space between the inner mandrel and the slip carrier, a circumferentially spaced series
of slips (40, 42) disposed in the annular space, with radially outer portions ofthe
slips being received in the slip windows for movement therethrough between radially
retracted and radially extended positions, a biasing structure operative to resiliently
bias the slips to their radially retracted positions, and a setting structure operative
to force the slips from their radially retracted positions to their radially extended
positions; a mill guide member (24) having a lower end portion connected to the top
end portion of the tubular anchor assembly, and a tubular upper end portion (24a);
and a tubular retrieval member coaxially securable to a milling pipe (30) and being
coaxially latchable in the tubular member coaxially secured to the upper mill guide
member end portion. |