Abstract: The invention relates to a swivel sub for a string to be lowered into a wellbore and a method of operation in a wellbore, wherein such swivel sub is used and comprises: —a first end provided with connection means for connecting a bottom section of a string; —a second end provided with connection means for connecting an upper section of the string; —a first member, including the first end and a sleeve portion opposed to the first end; —a second member including the second end and comprising a section opposed to the second end and partially located within the sleeve portion; the first member and the second member being arranged to rotate relative to each other.

Abstract: A reaming tool includes a tool body having a longitudinal axis and an upper end opposite a lower end and at least one blade extending outwardly from the external surface of the tool body. The blade includes a rolling element defining the gauge of the reaming tool, and a blade surface arranged undergauge of the rolling element and comprising a cutting surface.

Abstract: The present invention relates to a tool for selectively connecting or disconnecting components of a downhole workstring comprising a drive shaft (3) and a housing couplable to said drive shaft, and housing comprising first and second housing parts (21, 22) releasably connected to one another, transmission means such as a reduction gear mechanism (52-54) coupled to the drive shaft, the transmission means being arranged to selectively connect or disconnect the housing parts by rotating the drive shaft.

Abstract: The invention relates to a swivel sub for a string to be lowered into a wellbore and a method of operation in a wellbore, wherein such swivel sub is used and comprises: a first end provided with connection means for connecting a bottom section of a string; a second end provided with connection means for connecting an upper section of the string; a first member, including the first end and a sleeve portion opposed to the first end; a second member including the second end and comprising a section op posed to the second end and partially located within the sleeve portion; the first member and the second member being arranged to rotate relative to each other.

Abstract: A reaming tool includes a body having a longitudinal axis and an upper end opposite a lower end and a plurality of blades located on said body. Each blade includes a reaming surface having reaming inserts arranged on at least a portion of the reaming surface such that substantially equal load is applied on the reaming inserts in the longitudinal and circumferential directions, and wherein the reaming inserts comprise a truncated dome having a substantially flat top as an exposed contact area.

Abstract: The invention concerns a seal assembly (1) for sealing between a fixed member (10) and a rotatable member (3) adapted for rotating around an axis in relation to said fixed member. The seal assembly comprises a first ring member (4) adapted for being fitted in or on said fixed member circumferentially around said axis and having a first surface (34); a second ring member (6) adapted for being fitted circumferentially in or on said rotatable member and having a second surface (36) facing said first surface along a length; and a third ring member (7) between said second and said first surface, the distance between said second surface and said first surface being larger at the middle of said length and becoming smaller towards the extremities thereof.

Abstract: A steering assembly includes a housing having a longitudinal axis, a mandrel having a front connecting extremity and a rear connecting extremity, the mandrel passing through the housing and arranged in a first position coaxially to the longitudinal axis of the housing, a deflector device configured to exert a side force on the mandrel to offset the front connecting extremity of the mandrel from the longitudinal axis, and a tool face assembly configured to rotate the front connecting extremity of the mandrel in a desired direction.

Abstract: A reaming tool includes a body having a longitudinal axis and an upper end opposite a lower end and a blade located on said body, the blade including a reaming surface having one or more reaming inserts disposed on at least a portion thereof and a cutting surface having one or more cutters disposed on at least a portion thereof. One or more of said cutters are configured (a) so that an extended longitudinal axis of said cutter is positioned at an angle ? between 5 degrees and 85 degrees with respect to a plane perpendicular to the longitudinal axis of said body, or (b) on said cutting surface at a radial distance from said longitudinal axis less than said radial distances between said reaming inserts and said longitudinal axis.

Abstract: A downhole dual cutting reamer for bidirectional reaming of a wellbore with a tubular body with two cutting sections between end segments. Each cutting section has a plurality of helical blades separated by a flute, and wherein the helical blades are formed from at least two spiral angled sections connected together, with cutting components on the spiral angled sections. The cutting components can be polydiamond cutter nodes, high strength carbide cutting nodes, and tungsten carbide facing coating. The outer diameter of each cutting section is larger than the outer diameter of each of the end segments.

Abstract: The assembly comprise a bent sub (1411), and optionally a swivel (1480). The bend angle a of the bent sub in relation to the central axis of the assembly can be adjusted by rotating lower bend member (1431) relative to upper bend member (1430), which is non-rotatably attached to downhole motor (1460), using harmonic drive (1413) arranged between lower and upper bend members. In order to adjust the rotational orientation of the bent sub (1411), a swivel (1480) is provided having upper and lower swivel members (1432, 1433). Upper swivel member can be rotated relative to lower member, which is non-rotatably attached to the downhole motor, using a second harmonic drive (1423) arranged between lower and upper swivel members.

Abstract: The present invention relates to a tool for selectively connecting or disconnecting components of a downhole workstring comprising a drive shaft (3) and a housing couplable to said drive shaft, said housing comprising first and second housing parts (21, 22) releasably connected to one another, transmission means such as a reduction gear mechanism (52-54) coupled to the drive shaft, the transmission means being arranged to selectively connect or disconnect the housing parts by rotating the drive shaft.

Abstract: A steering assembly includes a housing having a longitudinal axis, a mandrel having a front connecting extremity and a rear connecting extremity, the mandrel passing through the housing and arranged in a first position coaxially to the longitudinal axis of the housing, a deflector device configured to exert a side force on the mandrel to offset the front connecting extremity of the mandrel from the longitudinal axis, and a tool face assembly configured to rotate the front connecting extremity of the mandrel in a desired direction.

Abstract: The invention relates to a device including an apparatus for measuring drilling or coring operation parameters using a bit attached to the end of a drill string, the measuring apparatus (10) being housed in a chamber (5) provided in a sleeve (1, 18) that is designed to be positioned between two drill pipes of the drill string or between the bit and a drill pipe of the drill string, or to form a coupling (18) for joining a cutting head (15) of the bit to a drill string, the chamber (5) leading into an axial channel (11) of the sleeve.

Abstract: Collection device for connecting a drilling tool, such as a bit, to the end of a drilling column, in which the connection device comprises a first element, with a first end, intended to be connected to the end of the drilling column, and a second element, with a second end, intended to be connected to the drilling tool, in which the second element is fixed to the first element so as to allow a translational movement in a longitudinal direction in order to make it possible to change the distance between the first end and this second end, characterized in that the connection device comprises a “pusher” structure for transmitting a thrust force from this first element towards the second element, comprising a set of “Belleville” washers making it possible to ensure that said thrust force, from the first element toward the second element, is substantially constant in any position of the second element with respect to the first element.

Abstract: A drill bit having fixed Polycrystalline Diamond Compact cutters is used to drill a borehole having a core stump therein. A plurality of additional fixed Polycrystalline Diamond Compact cutters are disposed in the dome of the bit and are usable to concentrate stresses in the top end of the core stump to facilitate the cutting down of the core stump.

Abstract: Two-centre rotary boring bit for boring wells, comprising, on the one hand, a pilot tool (1) comprising a body of revolution with an axial core (3) and radial blades (4) bearing cutting elements (5) and, on the other hand, an enlarging tool (2) fitted behind the pilot tool and laterally offset therefrom, the pilot tool having, on its front face, a central region (11) that has no cutting elements in order to allow the creation of a core sample (12), said central region being in communication with a cavity (13) situated between two blades (4) of the pilot tool (1) and serving to remove the core sample toward the periphery of the boring bit.