Abstract: A device (12) is disclosed which is for use in retrieving debris from a well. In one embodiment, the device includes an elongate body (20); a main bore (22) extending part way along a length of the body, along which fluid flows into the device; an opening (24) towards a lower end of the body; a main fluid chamber (28) in the body in fluid communication with the main bore; a flow restriction (30) provided in the main bore, through which fluid flows from the main bore and into the main fluid chamber; at least one chamber outlet (32) for directing fluid from the main fluid chamber into an annulus defined between the device and a well borehole wall; a return flow passage (40) extending between the body opening and the main fluid chamber, for return flow of fluid from the annulus to the main fluid chamber, to facilitate retrieval of debris from the well; and at least one fluid exit (44), for flow of fluid returned to the main fluid chamber through the return flow passage out of the device.

Abstract: A ball catcher for selectively catching and retaining drop balls in a well bore. The catcher is located on a workstring. A main bore (18) axially through the catcher is restrained to provide first (26) and second (28) bores of differing diameters. The first bore (26) is further restricted at a lower end, thus balls within the first bore (26) are retained and balls in the second bore (28) pass through the catcher. The bores preferably overlap to provide a channel (30) so that smaller balls can pass between the bores for release. In one embodiment, the second bore (28a) is located centrally through the catcher so that wireline tools and the like can be run through the catcher.

Abstract: There is disclosed a downhole packer for use in a well bore, and in particular, a packer which can be used for downhole testing. In an embodiment of the invention, a packer tool (10) for mounting on a work string to provide a seal against a tubular (32) is disclosed, the packer tool comprising a body (12) with one or more packer elements (18) and a sleeve (14), the packer tool being set by movement of the sleeve relative to the tool body compressing the one or more packer elements, wherein the tool has a plurality of bypass channels (16) to provide a fluid path past the packer elements, the sleeve including at least owe anchoring member (22, 50), the at least one anchoring member being actuate to contact the tubular by fluid pressure from the bypass channels when the packer is set.

Abstract: A downhole tool (10) for use in isolating a formation in a well bore from fluid pressure introduced from the surface. Mounted in a work string, the tool provides an axial throughbore (18) and radial outlets (40, 42) above and below a permanent sealing element (26), such as a diverter cup. Valve members (44, 50) which may be nested sleeves located within the axial bore are manipulated by activation through the work string, to move sequentially such that (a) a first circulation path is created around the seal, via the radial outlets and independent of the axial throughbore; (b) the axial throughbore is obstructed and a second circulation path is estate fished between the axial throughbore and the upper radial outlet; and (c) flow is re-established through the axial bore while maintaining the second flow path.

Abstract: A junk removal tool (10) for use in a well bore. The tool includes a multi-faceted face (42) of tungsten carbide to break up large pieces of junk. The junk is then captured in the tool via large area inlet ports (40) and collected in a trap (31). In one embodiment, valves (41) are placed at the inlet ports to prevent the out-flow of captured junk. A further embodiment includes a throat portion (52) to jet junk laden fluid into the tool.

Abstract: This invention relates to well cleaning methods and apparatus. In particular, this invention relates to a method of drilling and cleaning a wellbore. In one embodiment of the invention, a method of drilling and cleaning a wellbore (12) is disclosed. The method comprises the steps of providing a drill string (10) having a drill bit (28) and a cleaning tool (24) with selectively activatable cleaning members (34); drilling a wellbore using the drill bit while maintaining the cleaning members in a deactivated position; and pulling the drill string from the wellbore with the cleaning members in an activated position, to thereby clean the wellbore. A corresponding cleaning tool is also disclosed.

Abstract: A downhole tool for circulating fluid in a well bore. The tool includes an axial inlet and outlet with radial second outlets. A sleeve moves over the second outlets to control circulation of fluid. The sleeve can be selectively locked in an opened or closed configuration while the tool is in tension or compression. Variation of fluid pressure in the work string and stroking the tool move the sleeve between the operating positions. Cyclic operation of the tool is also described.

Abstract: A downhole tool which can perform a task in a well bore, such as circulating fluid radially from the tool. The function is selectively performed by virtue of a sleeve moving within a central bore of the tool. Movement of the sleeve is effected by dropping a ball through a ball seat on the sleeve. Movement of the sleeve is controlled by an index sleeve such that the tool can be cycled back to the first operating position by dropping identical balls through the sleeve. Embodiments are described wherein the balls are deformable, the seat is deformable and the seat provides a helical channel through which the ball passes.

Abstract: There is disclosed a cleaning tool for use in cleaning ferrous material from a wellbore, a cleaning assembly comprising a plurality of such wellbore cleaning tools, and a method of cleaning ferrous materials from a wellbore. In one embodiment, a cleaning tool (12) is disclosed which comprises a tool main body (19) and a number of magnets (20) mounted for selective movement relative to the main body between deactivated and activated positions. When in the activated positions, the magnets serve for attracting ferrous material present in a wellbore (10), to collect such material during passage of the tool along the wellbore, so that the ferrous material may be returned to surface to thereby clean the wellbore.

Abstract: A clamp (10) for holding two members (12, 14) together. The first member includes a recess (30) into which a fastener (38) is located. A further access port (42) is provided to the recess to allow a tool (44) to be used to operate the fastener. The second member is arranged to accept the fastener and so join the members. The recess and port are sized to prevent release of the fastener through the port. In this way, the fastener cannot easily be removed or lost when the clamp is in use and is tamperproof. Embodiments of a downhole tool are described where the clamp is used to hold portions of a sleeve around a body of the tool, and to hold scraper blades (384) and/or brushes (394) to the body.

Abstract: A downhole tool (10) for use in oil and/or gas well bores. The tool has a tubular body (20) and a sleeve (22) including stabilizer blades (30). The tool is ball (76), activated, weight activated or hydraulically activated to selectively jet fluid from the body through jetting ports (44A, 44B, 44C) on the blades. Thus the tool provides the features of a stabilizer, cleaning tool and circulation tool in-one.

Abstract: A packer tool for mounting on a work string in an oil and/or gas well is described. The packer is of the compression set type but includes a mechanism to prevent premature setting in the well. A method of running the tool with the completion is provided in order to advantageously allow an integrity test to be performed on the same run.

Abstract: A ball valve seat (10) is disclosed which provides a temporary seal for a plug (40). The valve seat comprises a substantially cylindrical body (30) of a first volume, which defines a seating surface (34). A pressure differential is developed across the valve seat when the plug sealingly engages the seating surface. The body is formed of an elastic material which compresses from a first volume to a smaller second volume by application of a force on the plug, to provide a clearance which is greater than a plugging dimension of the plug, thus allowing passage of the plug downstream. After passage of the plug, the body returns to the first volume.

Abstract: A ball catcher for selectively catching and retaining drop balls in a well bore. The catcher is located on a workstring. A main bore (18) axially through the catcher is restrained to provide first (26) and second (28) bores of differing diameters. The first bore (26) is further restricted at a lower end, thus balls within the first bore (26) are retained and balls in the second bore (28) pass through the catcher. The bores preferably overlap to provide a channel (30) so that smaller balls can pass between the bores for release. In one embodiment, the second bore (28a) is located centrally through the catcher so that wireline tools and the like can be run through the catcher.

Abstract: A releasable connector (10) for joining tubular members in a well bore. The connector (10) is a mating screwthread (38, 58) which is terminated on each member by abutting projections (24, 64), operating as a ratchet. This ensures torque is transmitted between the members in a uni-directionaly manner so that make-up torque is never applied to the screwheads when torque is applied to the members. A running tool (12) and a method of setting a liner in a well bore is also described which incorporate the connector (10) so that the liner may be part of a drill string and is left cemented in place in the well, after drilling is complete.

Abstract: A downhole tool (10) for use in isolating a formation in a well bore from fluid pressure introduced from the surface. Mounted in a work string, the tool provides an axial throughbore (18) and radial outlets (40, 42) above and below a permanent sealing element (26), such as a diverter cup. Valve members (44, 50) which may be nested sleeves located within the axial bore are manipulated by activation through the work string, to move sequentially such that (a) a first circulation path is created around the seal, via the radial outlets and independent of the axial throughbore; (b) the axial throughbore is obstructed and a second circulation path is estate fished between the axial throughbore and the upper radial outlet; and (c) flow is re-established through the axial bore while maintaining the second flow path.

Abstract: There is disclosed a downhole packer for use in a well bore, and in particular, a packer which can be used for downhole testing. In an embodiment of the invention, a packer tool (10) for mounting on a work string to provide a seal against a tubular (32) is disclosed, the packer tool comprising a body (12) with one or more packer elements (18) and a sleeve (14), the packer tool being set by movement of the sleeve relative to the tool body compressing the one or more packer elements, wherein the tool has a plurality of bypass channels (16) to provide a fluid path past the packer elements, the sleeve including at least owe anchoring member (22, 50), the at least one anchoring member being actuate to contact the tubular by fluid pressure from the bypass channels when the packer is set.

Abstract: A junk removal tool (10) for use in a well bore. The tool includes a multi-faceted face (42) of tungsten carbide to break up large pieces of junk. The junk is then captured in the tool via large area inlet ports (40) and collected in a trap.(31). In one embodiment, valves (41) are placed at the inlet ports to prevent the out-flow of captured junk. A further embodiment includes a throat portion (52) to jet junk laden fluid into the tool.

Abstract: A downhole tool for circulating fluid in a well bore. The tool includes an axial inlet and outlet with radial second outlets. A sleeve moves over the second outlets to control circulation of fluid. The sleeve can be selectively locked in an opened or closed configuration while the tool is in tension or compression. Variation of fluid pressure in the work string and stroking the tool move the sleeve between the operating positions. Cyclic operation of the tool is also described.

Abstract: A method and apparatus for temporarily increasing fluid pressure at a specific location in a work string to perform an operation in an oil or gas well bore. Apparatus is provided which, in a first position provides fluid flow through the work string; in a second position provides the desired increase in fluid pressure to perform the operation in the well bore by dropping a ball (62) into the apparatus; and, by shearing pins (52) to move a sleeve (50) within the apparatus, provides a third position which returns fluid flow through the work string via bypass channels (26) created in the apparatus around the ball. Operation of a pressure activated near bit reamer in conjunction with the apparatus is also described.