Abstract: The invention relates to a rock-cutting tool and a method for manufacturing this tool, which comprises knives comprising a layer of polycrystalline synthetic diamond (PSD), a diamond impregnation layer with diamond particles and bonding cobalt, characterized in that the PSD layer is supported directly, along a planar interface, on the diamond impregnation layer whose interface surface is planar by machining and with which the diamond particles are flush.

Abstract: The method involves a substrate 21 near which reagents 25 are provided. Pump (26) and Raman (27) photons make it possible to create a stimulated Raman emission during the synthesis (29) of the material. The Raman emission can be Stokes or anti-Stokes. In one embodiment of the invention, the zone where the synthesis (29) occurs is in an optical cavity and Raman photons (27) emitted by the Raman emission are reoriented toward the zone where the synthesis (29) occurs. In another embodiment of the invention, the zone where the synthesis (29) occurs is not in an optical cavity, and a stream of Raman photons (27) is created in an outside optical cavity before being sent toward the zone where the synthesis (29) occurs. The synthesis (29) preferably involves a CVD method or solidification by the Czochralski method.

Abstract: The invention relates to a rock-cutting tool and a method for manufacturing this tool, which comprises knives comprising a layer of polycrystalline synthetic diamond (PSD), a diamond impregnation layer with diamond particles and bonding cobalt, characterized in that the PSD layer is supported directly, along a planar interface, on the diamond impregnation layer whose interface surface is planar by machining and with which the diamond particles are flush.

Abstract: Stabilizer-reamer for drilling string characterized in that it comprises a mixture of diamond impregnated inserts, the mixture comprising cutting diamond impregnated inserts and wear resistant diamond impregnated inserts, said wear resistant diamond impregnated inserts having smaller diamond grain size and higher diamond concentration than said cutting diamond impregnated inserts.

Abstract: The method involves a substrate 21 near which reagents 25 are provided. Pump (26) and Raman (27) photons make it possible to create a stimulated Raman emission during the synthesis (29) of the material. The Raman emission can be Stokes or anti-Stokes. In one embodiment of the invention, the zone where the synthesis (29) occurs is in an optical cavity and Raman photons (27) emitted by the Raman emission are reoriented toward the zone where the synthesis (29) occurs. In another embodiment of the invention, the zone where the synthesis (29) occurs is not in an optical cavity, and a stream of Raman photons (27) is created in an outside optical cavity before being sent toward the zone where the synthesis (29) occurs. The synthesis (29) preferably involves a CVD method or solidification by the Czochralski method.

Abstract: Stabilizer-reamer for drilling string characterized in that it comprises a mixture of diamond impregnated inserts, the mixture comprising cutting diamond impregnated inserts and wear resistant diamond impregnated inserts, said wear resistant diamond impregnated inserts having smaller diamond grain size and higher diamond concentration than said cutting diamond impregnated inserts.

Abstract: A drill bit as used in particular in the oil well drilling field comprising a central body (2), cutting blades (3) protruding with respect to the body (2), both at the front of this body according to a drill direction and at the sides of this same body (2), and cutting elements (9) divided over an outer front surface (10) and over an outer lateral well sizing surface (11) comprised by each blade (3), wherein there are provided as cutting elements: in a central area (13) of the front surface (10), on at least one blade (3): at least one synthetic polycrystalline diamond compact cutting disc (12), and in a remaining area (14) of the front surface (10) of this blade, situated beyond said central area (13) with respect to the rotation axis, and on the other blades: thermally stable synthetic diamonds and/or impregnated diamond particles.

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

Abstract: Bit instrumentation and method for controlling drilling are disclosed that include multiple resistivity sensors 5B and accelerometer sensors 4 disposed within an insert portion 1B of the drill bit 1. The resistivity sensors have a beveled portion to provide an interference fit with a cavity formed within the insert portion 1B of the drill bit. Resistivity sensors 5B may be used to determine the motion of the bit 1 within the wellbore 106 including unstable bit operation such as bit whirling and bit tilting. As well, accelerometer sensors 4 may also be provided in conjunction with the resistivity sensors 5B to provide information concerning motion, accelerations and stresses applied to or within the drill bit 1.

Abstract: Method and device for detecting and/or measuring at least one geophysical parameter from a core sample (1), in particular in the oil sector, comprising, during an operation of core drilling with a sampler (2); arranging, substantially fixed relative to the sampler (2), a sensor (3) for detecting and/or measuring said parameter, directly downstream of the exit orifice (5) of the sampler (2) relative to the direction of withdrawal of the core sample (1), in the vicinity of the withdrawal path of the core sample (1), detecting and/or measuring values of the parameter at at least one location on the core sample (1) while the latter is being withdrawn from and/or moved back in the sampler (2), and processing of the detected and/or measured values of the parameter, in order to store them in memory and/or use them immediately.

Abstract: Electrodes are provided in a drill bit, or alternatively, in a coring bit, to measure variations in formation resistivity surrounding an earth borehole. Three orthoganal accelerometers are also provided in the drill bit, or in the coring bit, to monitor the dynamic behavior of the bit as functions of radial, axial and tangential accelerations.