Abstract: A downhole running system for use in setting a downhole tool in a bore includes a running tool comprising: radially extending members for holding the tool at a desired location in a bore and being selectively configurable, in a first configuration, to permit running the tool in through a restriction in a bore and, in a second configuration, to prevent passage of the tool through a restriction and to engage the wall of a bore to permit manipulation of the tool against a fixed point in the bore; an arrangement for releasably mounting a downhole tool on the running tool; and an arrangement for setting the downhole tool.

Abstract: 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.

Abstract: A tool for downhole use in oil and gas wells comprises a number of relatively-axially-slidable members. Upper and lower toothed locking slips are mounted on respective upper and lower members and a resilient ring member is mounted on a further member between the locking slips and is compressible into sealing engagement with a bore wall on relative movement of the slips towards each other. The locking slips are moved into radially extended bore wall engaging positions by relative axial movement of the respective members and the central member. The upper and lower locking slips are extended by application of downward force to the central member and the upper member, respectively, and the ring member is compressed into sealing engagement with the bore wall by application of an upward force to the lower member.

Abstract: An upstroke jar for use in downhole operations in an oil or gas well and for connection between a wireline and a tool comprises a casing defining an anvil and for connection to the tool, a hammer slidable axially within the casing for impacting with the anvil and for connection to the wireline, a hammer holder, a spring arrangement located between an abutment on the casing and an abutment on the hammer holder for compression on an operative movement of the hammer holder as a consequence of tension on the wireline and a connector releasable to free the hammer from the holder at the completion of the operative movement so that the freed hammer may impact with the anvil. The compression load on the spring present at the release is dependant on the extent of the operative movement from a rest position and the degree of compression of the spring means to obtain the operative movement. Adjustment of the release load present at the instant the hammer part is released by the connector is provided.