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: A device for uncoupling a drill string, the device including, in a longitudinal direction: a first structure that is intended to be attached to a drill string tube; a second structure that is intended to hold a cutting tool for drilling and is translatable relative to the first structure; and a thruster assembly between the first structure and the second structure. The thruster assembly is configured to exert a thrusting force on the second structure to separate the second structure from the first structure, the thrusting force being constant for every position of the second structure relative to the first structure.

Abstract: Rotary rock bit comprising a tool body having an axial core (1) and radial blades (2) made of steel, grooves (6) hollowed out in the edge (5) of the blades, transversely thereto, and cylindrical abrasive elements (8) comprising impregnated diamonds, which are disposed in the grooves, transversely to the blades.

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: A bit for drilling wells has a front face with radial blades having cutting elements distributed around the front face. A space for forming a core is situated at the center of the front face. A cavity is provided for evacuating the core towards a periphery of the bit. At least a portion of the cavity is situated between adjacent blades. The cavity is delimited by two lateral surfaces and a clearance surface set back with respect to the front face, and the cavity is open in a direction opposite the clearance surface. The bit may be used in methods for drilling wells and makes it possible to rapidly drill wells of great depth in all types of rock without the risk of clogging.

Abstract: A bit for drilling wells has a front face with radial blades having cutting elements distributed around the front face. A space for forming a core is situated at the center of the front face. A cavity is provided for evacuating the core towards a periphery of the bit. At least a portion of the cavity is situated between adjacent blades. The cavity is delimited by two lateral surfaces and a clearance surface set back with respect to the front face, and the cavity is open in a direction opposite the clearance surface. The bit may be used in methods for drilling wells and makes it possible to rapidly drill wells of great depth in all types of rock without the risk of clogging.

Abstract: Device comprising equipment for measuring parameters of a drilling or coring operation by means of a drillbit fixed to the end of a drill string, measurement equipment (7) being housed in a chamber (5) made in a coupling (1, 18) that is designed to be interposed between two drill string pipes or between the drillbit and a drill string pipe, or to constitute an adapter (18) for a cutting head (15) of the drillbit of a drill string.

Abstract: Rotary rock bit comprising a tool body having an axial core (1) and radial blades (2) made of steel, grooves (6) hollowed out in the edge (5) of the blades, transversely thereto, and cylindrical abrasive elements (8) comprising impregnated diamonds, which are disposed in the grooves, transversely to the blades.

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: The invention relates to a bit for drilling wells comprising:—a front face,—a plurality of radial blades (2) provided with cutting elements (3), the blades being distributed around the front face,—a space (4) for forming a core (10), the space being situated at the centre of the front face,—a cavity (5) for evacuating the core towards the periphery of the bit, the cavity being situated between two adjacent blades. The invention also relates to a method for drilling wells using the bit. The invention makes it possible to rapidly drill wells of great depth in all types of rocks without the risk of clogging.

Abstract: Device comprising equipment for measuring parameters of a drilling or coring operation by means of a drillbit fixed to the end of a drill string, measurement equipment (7) being housed in a chamber (5) made in a coupling (1, 18) that is designed to be interposed between two drill string pipes or between the drillbit and a drill string pipe, or to constitute an adapter (18) for a cutting head (15) of the drillbit of a drill string.

Abstract: A drill and/or core tool, in particular for oil drilling and/or coring, comprising a body (2) showing a substantially cylindrical peripheral surface (3) and a front (4), blades (5) which extend from the front (4) till over the peripheral surface (3) and which show each a leading edge (6), possibly PDC cutting elements (7) which are situated at least in a central area (15A) of the front (4) and the longitudinal axes of which are transverse to the rotation axis of the tool (1), and comprising moreover, on at least one blade (5), outside said central area (15A): PDC (7C) and/or secondary (10) cutting elements which show each a cutting edge (8), forming together the leading edge (6) of the blade (5), and the longitudinal axis of which is transverse to the rotation axis, and at least one associated cutting element (10A) which is situated behind at least one of the PDC (7C) or secondary (10) cutting elements, which shows a cross-section of the same shape, at least for its portion protruding from the blade (5), than