Abstract: A method of drilling and cleaning a wellbore whilst rotating the drill string after full drilling depth is reached without running the drill string out the bore to install a clean up work string is disclosed wherein a drill string having a drill bit at one end includes at least one near bit selectively activatable cleaning tool (10, 11, 12) mounted within the length of the drill string, said cleaning tool having a cleaning member (18) adapted to be moved from a close fitting stowed configuration within a recess (17) to a deployed configuration upon a body of the tool, wherein the cleaning member has magnets (19, 43) for use in positioning thereof, and compact tools for scraping, milling and brushing with improved resistance to ingress of detritus, debris and formation particulates are disclosed.

Abstract: A cleaning tool (1) for use in cleaning ferrous material from a wellbore has a magnetic cleaning element (14) mounted to a tool body (2) within a slot (5) using a releasable concealed interference fit fastener assembly (15) comprising a fastener member having a head (16), and a shank (17) with a configured end (18) and a deformable fastener ring (20) adapted to fit closely over the shank, and a press-fit collar (21) adapted to deform the deformable fastener ring upon the configured end of the shank when assembled, and wherein the respective head and collar are each flanged to permit an interference fit with a corresponding contact surface of the tool body around said slot.

Abstract: A cleaning tool for cleaning a liner top in a well bore. The tool includes cleaning elements, typically scrapers, which are arranged eccentrically to an axial bore through the tool. The elements are biased outwardly to contact an inner surface of a polished bore receptacle (PBR) at a position with a curvature to match the PBR and to present leading edges of each element when positioned at a surface of a neighbouring casing. The tool may further provide a top dress mill and act as a packer actuator sub. This provides a tool which performs a number of functions on a single trip in a well bore.

Abstract: A downhole flow control tool 1, includes a flow control member in the form of a sleeve 8, and comprises a main body 2 having a longitudinal internal bore 3 extending therethrough, an upper end 4 having a box section 6, and a lower end 5 with a pin section 7, which enable connection of the tool 1 into a work string. The flow control sleeve 8 is mounted for movement relative to the bore 3 between at least a closed and one of several open positions. The tool body 2 includes several flow ports extending through a wall of the body 2 and spaced around a circumference of the body 2. The tool provides multiple fluid flow control options for directing and splitting fluid flow for example during a drilling operation to clear settled cuttings by suitable location of the tool.

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: 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 method of controlling fluid flow through a hollow body, uses a ball seat assembly (12) comprising a hollow body (14) defining a bore (16) and a ball seat (18) mounted said bore, the ball seat being moveable relative to the bore between an extended position in which the seat defines a restriction to passage of a ball (20) along the bore, and a retracted position spaced axially along the bore from the extended position and in which position passage of the ball along the bore is permitted. A subsequent reduction in the fluid pressure force acting on the ball seat facilitates movement of the seat from the extended position shown in the upper half of FIG. 1, to the retracted position shown in the lower half of the Figure, to permit passage of the ball through the bore to thereby re-open fluid flow through the bore.

Abstract: The invention relates to a cement evaluation method and tool. In particular, the invention relates to a method of producing a wellbore cement bond log for evaluating a condition of cement in cased or lined portions of wellbores, and to a corresponding cement bond logging assembly. In an embodiment of the invention, a method of producing a wellbore cement bond log is disclosed which comprises the steps of running a cement evaluation tool (210) and a wellbore cleaning tool (222) into a wellbore (202); acquiring data relating to at least one property of a cement bond (212) of the wellbore using the cement evaluation tool; and generating a log of the acquired data.

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 valve assembly (10), a seal assembly, an indexing arrangement, a downhole/circulation tool (12) incorporating a valve seat assembly, methods of controlling fluid flow and fluid circulation are described, wherein the valve assembly is used for controlling fluid flow by bringing a valve member (34) into sealing abutment with a deformable body (36) of the valve seat assembly, wherein at least one locking element in the form of a dog or key (38) mounted for movement relative to the body selectively between a retracted position, shown in FIGS. 1 and 2, and an extended position, shown in FIG. 7 permits a good seal between the valve member and the valve body whilst ensuring that the valve member will not be prematurely or inadvertently blown through a bore (40) in the valve body, due, for example, to variations in well conditions such as temperature and pressure.

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.

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-directionally 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 which includes a locking bar to allow movement of a sleeve within the tool over a pre-defined range. The range is defined by a recess arranged axially or circumferentially in the tool, in which the bar locates. Fluid can be vented from the recess to provide a hydraulic brake, to prevent premature shearing of any shear pins in the tool. A stabiliser, jetting and circulating tool is described including the locking bar together with applications when incorporated in a bottom hole assembly. The tool allows multiple operations to be performed on a single trip.

Abstract: A cleaning tool for cleaning a liner top in a well bore. The tool includes cleaning elements, typically scrapers, which are arranged eccentrically to an axial bore through the tool. The elements are biased outwardly to contact an inner surface of a polished bore receptacle (PBR) at a position with a curvature to match the PBR and to present leading edges of each element when positioned at a surface of a neighbouring casing. The tool may further provide a top dress mill and act as a packer actuator sub. This provides a tool which performs a number of functions on a single trip in a well bore.

Abstract: The invention relates to a wellbore cleaning assembly, wellbore cleaning apparatus comprising a wellbore cleaning assembly, and to a method of cleaning a wellbore. In an embodiment of the invention, a wellbore cleaning assembly (10) is disclosed which is run into a wellbore (14) to be cleaned on a work string (20). The cleaning assembly (10) comprises a number of cleaning elements (24, 26, 28, 30) for cleaning a wall (22) of the wellbore (14); and an oscillator (36) coupled to the at least one cleaning element (24, 26, 28, 30), for generating an oscillating movement of the at least one cleaning element (24, 26, 28, 30) relative to the work string (20).

Abstract: A cleaning tool and method of cleaning a liner top in a well bore. The tool includes cleaning elements, typically scrapers, which are arranged eccentrically to an axial bore through the tool. The elements are biased outwardly to contact an inner surface of a polished bore receptacle (PBR) at a position with a curvature to match the PBR and to present leading edges of each element when positioned at a surface of a neighboring casing. The tool may further provide a top dress mill and act as a packer actuator sub. This provides a tool which performs a number of functions on a single trip in a well bore.

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.