Abstract: A used radial tyre tread, folded into a minimum of three loops and held in compression, in a lateral external circlip, to form a flexible, resilient, abrasion resistant bollard with anisotropic properties. By extending the lateral external circlip, longitudinally, more tyre treads can be added to form a baffle or a barrier. The removal of the tread section significantly reduces the bulk of the waste tyre.

Abstract: The present invention relates to a downhole tool (102) for selectively opening and closing a lateral borehole extending from a primary borehole. The tool (102) comprises a body (104) incorporating a wall provided with an opening (116) extending therethrough; a deflector member (106) slidably mounted in the body (104) and having a deflecting surface (126) for deflecting, in use, downhole equipment laterally within the body (104). The deflector member (106) is slidable between an open position, in which the deflecting surface is located adjacent and facing towards said opening so that, in use, downhole equipment laterally deflected by the deflecting surface is directed through said opening, and a closed position, in which the deflecting surface is oriented relative to said opening so as to prevent downhole equipment from being laterally deflected through said opening during use. In either position, equipment may pass into the primary borehole downhole of the primary/lateral junction.

Abstract: A downhole apparatus which can be used as multi-cycle circulating subs utilized in downhole drilling operations, includes a piston (242) slidably mounted in a body between positions in which at least one aperture in the body is opened and closed. Movement of the piston (242) is controlled by a pin (86), secured to one of the body and a control member, and a control groove (52) formed in the other of the body and control member for receiving a portion of the pin. An arrangement of elements (232, 276) respectively connected to the control member and body is such as to normally resist axial movement of the control member from a first axial position to a second axial position. A spring (44) is located in a chamber for biasing the piston (242). The chamber is vented by an opening in the body.

Abstract: The present invention relates to downhole apparatus for limiting rotation of a rotor (4) relative to a stator (8) associated with said rotor (4). Apparatus according to the invention is provided with a locking member (12) movable from a first axial position to a second axial position by the application of a static fluid pressure to a differential area of said locking member (12). The apparatus is characterised by means for selectively applying static fluid pressure to said differential area of said locking member (12).

Abstract: The present invention relates to a downhole tool (102) for selectively opening and closing a lateral borehole extending from a primary borehole. The tool (102) comprises a body (104) incorporating a wall provided with an opening (116) extending therethrough; a deflector member (106) slidably mounted in the body (104) and having a deflecting surface (126) for deflecting, in use, downhole equipment laterally within the body (104). The deflector member (106) is slidable between an open position, in which the deflecting surface is located adjacent and facing towards said opening so that, in use, downhole equipment laterally deflected by the deflecting surface is directed through said opening, and a closed position, in which the deflecting surface is oriented relative to said opening so as to prevent downhole equipment from being laterally deflected through said opening during use. In either position, equipment may pass into the primary borehole downhole of the primary/lateral junction.

Abstract: The present invention relates to downhole apparatus and particularly, but not exclusively, to multi-cycle circulating subs used during downhole drilling operations. Apparatus is provided comprising a piston (242) slidably mounted in a body between positions in which at least one aperture in the body is opened and closed. Movement of the piston (242) is controlled by a pin (86), secured to one of the body and a control member, and a control groove (52) formed in the other of the body and control member for receiving a portion of the pin. An arrangement of elements (232, 276) respectively connected to the control member and body is such as to normally resist axial movement of the control member from a first axial position to a second axial position. A spring (44) is located in a chamber for biasing the piston (242). The chamber is vented by an opening in the body.

Abstract: Bypass valve for use in wellbores, particularly during the setting of hydraulic anchor packers, a bypass valve is provided with a body (4) incorporating a wall provided with at least one opening (20) and a piston (30) slidably mounted and having a longitudinal bore extending therethrough. The piston (30) is movable between a first position, in which the bore of the piston (30) is substantially isolated from the exterior of the body (4), and a second position in which a passage is provided from the bore of the piston (30) to the exterior of the body (4). Constraining means (42, 52) prevent movement of the piston (30) from the first to the second position. Overriding means are provided to permit movement to the second position.

Abstract: A well bore deflector tool which is used primarily for deflecting tools, lining and the like through a window which has been milled in the side of a well bore casing includes a deflector face (3) at an upper end thereof and slips (9, 10) for selectively gripping and releasing a tie back receptacle (8) and/or a well bore casing (6) at a location below the deflector face (3). The slips are operable for gripping in response to engagement of the deflector tool (1) with a tie back receptacle (8). Accordingly, the invention provides a simple and automatic device for locking the deflector tool in a required angular position.

Abstract: Bypass valve for use in wellbores, particularly during the setting of hydraulic anchor packers, a bypass valve is provided with a body (4) incorporating a wall provided with at least one opening (20) and a piston (30) slidably mounted and having a longitudinal bore extending therethrough. The piston (30) is movable between a first position, in which the bore of the piston (30) is substantially isolated from the exterior of the body (4), and a second position in which a passage is provided from the bore of the piston (30) to the exterior of the body (4). Constraining means (42, 52) prevent movement of the piston (30) from the first to the second position. Overriding means are provided to permit movement to the second position.

Abstract: The present invention relates to bypass valves for use in wellbores, particularly but not exclusively to bypass valves used during the setting of hydraulic anchor packers. A bypass valve (2) is provided with a piston (30) slidably mounted adjacent a body member (4) having at least one opening (20) extending therethrough. The piston (30) is moveable between a first position establishing a passage from the interior of the body (4) to the exterior thereof via the at least one opening (20) and a second position isolating the interior of the body (4) from the exterior thereof. A second piston may be provided for increasing, in response to a predetermined fluid pressure differential across the length of the piston (30), the force exerted on the piston (30) by a given flow of fluid through the bypass valve (2) such that the resultant force on the piston (30) is insufficient to move the piston (30) to the second position.

Abstract: This invention relates to apparatus for scraping the inner surface of a wellbore. A scraper assembly (2) is provided comprising a scraper element (6) incorporating: a generally cylindrical member defined by a wall having a slot extending through the wall thickness; and at least one tooth member provided on the outer surface of the wall for scraping engagement with a wellbore. The present invention thereby provides a scraper assembly which is relatively convenient and inexpensive to manufacture and which may be considered as a disposable item of downhole equipment.

Abstract: This invention relates to hydraulic anchor packers for use in well bores and, more particularly, to inflatable anchor packers. A hydraulic anchor packer (90) is provided having an inflatable packer element (36) incorporating a cylinder (38) and an elastomer sleeve (44) provided on the exterior surface thereof. The elastomer sleeve (44) but free of the cylinder (38) intermediate the end portions. Means are provided for causing fluid from within the cylinder (38) to flow through an aperture (48) and between the elastomer sleeve (44) and the exterior surface of the cylinder so as to radially expand the sleeve (44). Means are also provided for trapping fluid so as to prevent relaxation of the sleeve (44). Pressure relief means (92, 94, 98) permits fluid located exteriorly of the packer (90) to move past the sleeve (44) as the sleeve (44) expands whilst in engagement with a well bore wall during use. Thus, the downhole half of the sleeve (44) may freely expand and displace fluid located below the packer (90).