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 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 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 downhole tool for use in a cased or lined well bore (40), the tool including a barrier (36) arranged on an outer surface of the tool. The barrier may be of a resilient material so that it can be deformed on actuation to control the passage of fluid between the tool and the casing or liner. Fluid flow is thus selectively diverted through flow paths (22) in the tool. Embodiments are described for actuating the barrier by hydraulic means and for filtering the fluid within the flow paths.

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 use in the removal of burrs or other unwanted material from an inner surface of a pipeline, well casing or other tubular. The tool has a plurality of milling elements, which may be biased against the surface or retracted from the surface to disengage the tool from the tubular. A drop ball mechanism with a fluid by-pass is described for disengaging the milling elements.

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 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 tool (10) for selectively circulating fluid in a borehole is disclosed. The tool operates via the use of a combination of deformable drop balls (36) and smaller hard drop balls (40). In use a deformable drop ball (36) moves a sleeve (20) exposing a radial port (30,32) to provide fluid circulation radially from the tool. The smaller drop ball (40) can then obstruct the radial port (32,30) and by the increased pressure the deformable drop ball (36) is extruded through the tool. The resulting pressure differential as the drop ball (36) moves causes the sleeve (20) to rise, releasing the smaller drop (40) ball and closing the radial port (32,30). The process can be repeated to selectively circulate fluid through the tool.

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.

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 tool (10) for selectively circulating fluid in a borehole is disclosed. The tool operates via the use of a combination of deformable drop balls (36) and smaller hard drop balls (40). In use a deformable drop ball (36) moves a sleeve (20) exposing a radial port (30,32) to provide fluid circulation radially from the tool. The smaller drop ball (40) can then obstruct the radial port (32,30) and by the increased pressure the deformable drop ball (36) is extruded through the tool. The resulting pressure differential as the drop ball (36) moves causes the sleeve (20) to rise, releasing the smaller drop (40) ball and closing the radial port (32,30). The process can be repeated to selectively circulate fluid through the tool.

Abstract: A downhole tool (1) for providing the dual role of cleaning and milling within a well bore 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 centraliser 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 tool and method of operation is described for collecting fluid samples in a downhole environment. The tool is connectable on a work string and is activated by dropping a ball through the work string. On activation a sleeve arranged on the body of the tool is caused to shift from a first to a second position thereby creating a chamber between the sleeve and body. The sample fluid is drawn into the chamber as it is created and is prevented from exiting by a non-return valve. The tool locks the sleeve in the second position to fix the chamber. The sample can then be retrieved along with the tool.

Abstract: A wellbore system with a tubular string extending from an earth surface down into a wellbore in the earth, a packer system with a selectively settable packer element, and a disconnect located between an end of the tubular string and the packer system, the disconnect operable from the surface by imposing a downward force on the tubular string. In one aspect the packer system's packer element is a tension-set packer element. A wellbore disconnect with a top sub (122), a mandrel (126) having an upper end secured to the top sub and a portion below the upper end releasably secured with at least one releasable member (138) to a carrier member (136), the carrier member having apparatus (156) for selectively gripping the mandrel, the apparatus for selectively gripping the mandrel also selectively gripping a bottom sub (144) within which the mandrel is moveable, the at least one releasable member releasable in response to a downward force on the disconnect.

Abstract: A cleaning tool (1) for cleaning casing within a wellbore is comprised of an upper (3) and lower (4) sleeve which are mounted via ball bearings (5) on a work string (2). The ball bearings enable the upper (3) and lower (4) sleeves to have no or negligible rotational movement notwithstanding rotation of the work string (2). The upper (3) and lower (4) sleeve limit the axial movement of the cleaning tool (1) along the work string (2). The cleaning tool (1) is further comprised of at least one lantern (6) which supports the plurality of cleaning member (7) which may be brushes or scraping blades.

Abstract: The present invention is directed to a method of cleaning a well riser. In particular, the method comprises the steps of suspending in a drill pipe from the surface a circulating tool in the well riser, and causing the circulating tool to axially collapse so as to open one or more radial outlets in the tool and allow cleaning fluid to be expelled out of the tool and impact on the inside of the well riser.

Abstract: A downhole tool and method of operation is described for collecting fluid samples in a downhole environment. The tool is connectable on a work string and is activated by dropping a ball through the work string. On activation a sleeve arranged on the body of the tool is caused to shift from a first to a second position thereby creating a chamber between the sleeve and body. The sample fluid is drawn into the chamber as it is created and is prevented from exiting by a non-return valve. The tool locks the sleeve in the second position to fix the chamber. The sample can then be retrieved along with the tool.

Abstract: Well cleaning apparatus comprises a tubular body member attached to a work string which supports one or more resilient and pliable cleaning members. Each cleaning member is provided with a means for allowing bypass as sized and adapted to wipe the well casing. In one embodiment, the apparatus may be used to plunge the well with the cleaning members providing the sealing relationship with the well casing.