Abstract: The mandrel comprises a body having a longitudinal axis together with a radially-expandable annular assembly. The annular assembly presents a peripheral surface for pressing against a borehole and a peripheral surface for pressing against the body. Around the longitudinal axis, the annular assembly comprises a plurality of radial-expansion blocks. Each block has a first bearing surface, a second bearing surface, and two side surfaces disposed respectively facing a side surface of at least one adjacent block. The block are displaceable relative to one another between a radially-contracted configuration, and a radially-expanded, engagement configuration in which each side surface of a block is in contact with the side surface of the adjacent block.

Abstract: The device relates to an installation comprising a cavity extending from the surface of the ground and provided with at least one electrically conductive tubular element. The device comprises a single-strand smooth cable for supporting an action and/or measurement assembly, which cable is electrically conductive and has a breaking strength greater than 300 daN, and is disposed in the tubular element. The surface of the cable is electrically insulated at least in part from said tubular element. The device includes transmitter means and receiver means for transmitting and receiving an electrical and/or electromagnetic signal, said means being situated in the vicinity of the surface and in the cavity, and being electrically connected to the cable and to the tubular element and/or an underground formation. The invention is applicable to transmitting information and to controlling tools in an oil well.

Abstract: A method analyzes the hydrocarbon composition of geological strata. The method includes an analysis of gaseous hydrocarbon concentrations contained in drilling muds. According to the method, for a given depth range, gaseous hydrocarbon concentration ratios are established in pairs at essentially-identical depths. Subsequently, a sub-set of the ratios is selected in order to form a signature that is representative of the gaseous hydrocarbon composition of the depth range. The aforementioned signature is defined by the at least one straight line representing the concentration of a first gaseous hydrocarbon in relation to the concentration of a second hydrocarbon. The signature is then compared to reference signatures in order to determine the hydrocarbon concentration of the geological stratum corresponding to the depth range.

Abstract: A method includes the phases of measuring the quantity of a given gas in the gases extracted from a calibration sample of a calibration mud, in at least two stages for extraction under predetermined conditions. A family of curves representing the extraction, under the predetermined conditions, of the given gas from the drilling mud, is established on the basis of the measurements carried out. The method also includes the phases of measuring the quantity of given gas in the gases extracted from an analysis sample of the drilling mud in an extraction stage, under the predetermined conditions; and computing the given gas content of the drilling mud on the basis of the measured quantity of given gas and of a curve of the family.

Abstract: The invention relates to a method of analysing the hydrocarbon composition of geological strata, comprising an analysis of the gaseous hydrocarbon concentrations contained in the drilling muds.According to the invention, for a given depth range, gaseous hydrocarbon concentration ratios are established in pairs at essentially-identical depths. Subsequently, a sub-set of said ratios is selected in order to form a signature that is representative of the gaseous hydrocarbon composition of the depth range. The aforementioned signature is defined by at least one straight line representing the concentration of a first gaseous hydrocarbon in relation to the concentration of a second hydrocarbon. Said signature is then compared to reference signatures in order to determine the hydrocarbon concentration of the geological stratum corresponding to the depth range.

Abstract: A method of transmitting information between a salt-cavern and the surface of the ground, the cavern being drilled in geological formation beds and being connected to the surface via an access borehole cased at least in part by metal tubes and presenting at least one safety valve, the method consisting in suspending a string of tools from a hanger system positioned in the access borehole downstream from the safety valve and in electrical contact with the metal tubes, the string of tools including at least one measuring device connected to the hanger system via a first segment of conductor cable and an information transceiver operating by means of waves and connected to the measuring device via a second segment of conductor cable, the transceiver being positioned in such a manner as to be in contact with structural means linked to the cavern; and establishing coupling between the transceiver and the structural means, in order to enable information to be transmitted between the measuring device and the surface

Abstract: The invention relates to a quick-acting valve actuator comprising: a driven member (31) driven by a drive device (35) suitable for causing the driven member (31) to travel along a stroke (C1) to a trigger position; and locking-and-trigger means (41) co-operating with the driven member (31) and the actuator member (21) so that: during the stroke (C1), the actuator member (21) is stationary, and the driven member (31) is moving; and when the driven member (31) reaches the trigger position, the driven member (31) is held stationary, and the actuator member (21) is urged by prestress means (51) to open or close the valve.

Abstract: This invention concerns a module for extracting samples in gas phase of compounds present in an underground working liquid, the extractor module including a receptacle for the liquid, associated with a device for stirring the liquid, a liquid inlet duct, a liquid evacuation duct, an auxiliary gas admission duct, and an outlet duct for delivering auxiliary gas and gas extracted from the liquid. The auxiliary gas admission duct and the evacuation duct include a common segment, for preventing the auxiliary gas from passing is provided in the evacuation duct downstream from the common segment in the liquid-passing direction.

Abstract: The present invention relates to a device for connecting two metal parts. The device comprises a first element (1) having a female conical surface and a second element (5) having a male conical surface, at least one of the two surfaces being coated with a thin layer (12) of an electrically insulating material. The two elements (1, 5) are inserted one inside the other so that they are mechanically joined and electrically insulated.

Abstract: Seismic waves are recorded twice by a reference sensor (8) above ground and by a sensor (18) located in the drill hole (1). Measurements are synchronized by a clock system, the clock associated with sensor (18) being designed specifically for providing such synchronization in spite of operating conditions prevailing at the bottom of a drill hole (vibrations, shocks, temperature).

Abstract: A device and method for transmitting information between a well bottom and the surface by means of electromagnetic waves. The device includes transmitting information on either side of a valve (9) placed in a string of pipes (4) in a well by means of two electromagnetic wave transmitter-receiver unit (1, 2) placed on either side of the valve. In the device, unit (2) placed above valve (9) is lowered by means of logging type cable (3) into inner space of pipes (4).

Abstract: Information can be transmitted between equipment at the bottom of a drilling operation and the surface. A transceiver is provided at the surface, and is connected to both the earth, or the bottom of the ocean in an offshore operation, spaced from the drilling operation, and metal pipework used in the drilling operation. A transmitter/receiver is used for applying and receiving electric signals between two points on the metal pipework. The two points are separated at a substantial distance along the metal pipework such that the resistance of the metal pipework connecting the two points is relatively low but greater than zero. No insulating junction is then needed to be interposed between the two points in the metal pipework connecting the two points. Preferably, the transmitter/receiver has upper and lower conductors with first and second polar ends at the two points, thus forming a dipole of substantial length across the metal pipework.

Abstract: A joint for end-to-end coupling of two tubular elements includes tapered coupling surfaces on the tubular elements which are bonded together by adhesive. The coupling surfaces comprise a plurality of cylindrical sections of gradually increasing and decreasing diameters, respectively. A plurality of axially spaced-apart centering rings are interposed between the tubular elements to provide proper positioning thereof and to facilitate injection of bonding material between the coupling surfaces. A series of axially spaced-apart conducting rings forming part of an antenna surround one of the tubular elements and are insulated therefrom by a layer of bonding material. The conducting rings are separated from each other by toric joints and shims. Openings are provided in one of the tubular elements for injecting the bonding material under pressurized conditions, and an insulating sheath is bonded to inner peripheries of the tubular elements.

Abstract: A method and apparatus for sampling the gaseous content of a liquid laden with solids initially involves sampling the liquid as close as possible to the source of the liquid. A strainer housing having a strainer plate for filtering out debris in the liquid is connected to a suction pump for sucking the liquid into the housing and to the pump. The pump delivers the sampled liquid to a degassing device mounted on a frame with the pump. The degassing device agitates the liquid to liberate gases suspended therein. The gases are then collected from the degassing device so that the gases may be analyzed. A motor mechanism on the frame drives the pump, a rotating agitator in the degassing device and a rotating scraper on the exterior of the strainer plate simultaneously. This method and apparatus are particularly applicable to the sampling of drilling mud from an oil well exploration site for purposes of analyzing the hydrocarbon content of the drilling mud.

Abstract: An antenna structure for transmitting signals from a transmitter at the bottom of a drill well to the earth's surface which includes a drill collar extending in an axial direction and which is adapted to support a transmitter therein, a cylindrical metal sleeve for forming part of an antenna for electromagnetic wave transmission, the cylindrical metal sleeve being disposed around the drill collar and adapted to be connected electrically to the transmitter, an insulating sheath between the cylindrical metal sleeve and the drill collar and a plurality of metal rings disposed between each opposite axial end of the cylindrical metal sleeve and confronting opposite axial end of the insulating sheath. The cylindrical metal sleeve has a diameter greater than the diameter of the drill collar and the insulating sheath has an axial length longer than the axial length of the cylindrical metal sleeve.

Abstract: A device for transmitting signals from a transmitter at the bottom of a drill well to the earth's surface including a drill collar which extends in an axial direction, a transmitter disposed in the drill collar, a cylindrical metal sleeve from forming part of an antenna for electromagnetic wave transmission, the cylindrical metal sleeve being disposed around the drill collar and connected electrically to the transmitter, the cylindrical metal sleeve having a diameter greater than the diameter of the drill collar and having an axial length shorter than the axial length of the drill collar, and an insulating sheath disposed between the cylindrical metal sleeve and the drill collar, the insulating sheath having an axial length shorter than the axial length of the drill collar.

Abstract: A device for simultaneously measuring various parameters such as the flow rate, the density and the temperature of the drilling mud issuing from a well during the drilling operation, and for recording said parameters, comprising a V-shaped measuring conduit the upstream portion of which is connected to the upper portion of a chute through which said mud flows and which opens into the atmosphere, while the downstream end of said measuring conduit is connected to a down spout directing said mud to oscillating screens.