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 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 wellhead seal unit for sealing a subsea oil and/or gas well at the wellhead. The unit comprises a sleeve, sealingly engaged to the workstring and to which, blow out preventer rams can engage. The unit allows the workstring to be rotated and reciprocated within the wellbore without releasing the seal. Methods of cleaning the sealed well and performing an inflow test are described.

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: 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 disengageable downhole tool (10) for use in the oil and gas industry. The tool can be decoupled from a work string to allow further tools to be operated from the work string on being run deeper into a well. The tool is then picked-up by the work string on retrieval from the well. In one embodiment a milling tool (28, 32) is described having a hex-drive system for operation of the tool from the work string with coupling and decoupling being achieved via shear pins (40) and a mating ledge and shoulder.

Abstract: A safety trip button (12) is described for a weight-set downhole tool. The button operates between the tool body (36) and a sleeve (34) of the tool, locking them initially together. When the tool reaches a selected formation (44) in a well bore, the button engages the formation (44) which unlocks the body and sleeve. The button is kept in the unlocked position by virtue of the formation while the tool is set. The button prevents premature setting of the tool and finds application on weight set tools such as packers and circulation tools.

Abstract: A downhole tool for connection in a work string to prevent premature activation of weight set tools on the work string. The tool has moveable pads which contact the tubing wall and thereby support the weight of the work string. The pads are activated by increasing fluid pressure in the annulus between the tool and tubing wall and deactivated by increasing fluid pressure through the central bore of the tool.

Abstract: A downhole cleaning tool (10) for oil and gas wells. Brushes, scraper, wipers (32) and the like are mounted on a sleeve (14) over a tubular body (12), and the members successively moved towards and away from an inner surface of a tubular to be cleaned. Movement is created by a jarring action on the tool with the sleeve traveling over undulating profiles (26) on the body to actuate the cleaning members. The tool may be deployed on a slickline or wireline.

Abstract: A downhole tool (1) for providing the dual role of cleaning and milling within a wellbore casing or liner is described. In an embodiment scraper blades (6) are mounted on a body (2) together with a milling sleeve (4). Additionally, a centralizer sleeve (3) is incorporated as is a filter and/or junk basket for collecting debris is dislodged from the casing or liner during the cleaning and milling operation. The milling sleeve (4) can be locked onto the body (2) while the cleaning members e.g. scraper blades (6) may be free floating around the tool (1).

Abstract: A downhole packer for providing a seal in a well bore to allow integrity testing of the well bore. The packer is set by a sleeve movable on a body of the packer being set down on a formation in the well bore. Movement of the sleeve compresses one or more packing elements. The packer further includes a by-pass channel which allows fluid to pass through the tool as it is run in the well bore, and brushes or scrapers for cleaning the well bore and preparing the location for the packer elements to be contacted upon.