| 摘要 |
PCT No. PCT/GB92/01568 Sec. 371 Date Feb. 28, 1994 Sec. 102(e) Date Feb. 28, 1994 PCT Filed Aug. 27, 1992 PCT Pub. No. WO93/05267 PCT Pub. Date Mar. 18, 1993.A pack-off tool comprises a main tubular body including an expandable sealing element located between two non-expandable ring members and being mounted on a mandrel and in sealing engagement therewith at axially spaced locations. The tubular body is axially compressible into a radially extended configuration for sealing engagement with a bore wall. A communicating bore extends through the body between the sealing locations. In use, a high pressure on one side of the tool pushes between the high pressure side of the tubular body and the bore wall, through the communicating bore and into a space between the tubular body and the mandrel, and tends to push the other, lower pressure side of the body outwardly into tighter sealing engagement with the bore wall.
|
