Abstract: In a process for obtaining seismic data relating to an exploratory well, a seismic wave transmitter and a seismic wave receiver are provided, one arranged on the surface adjacent the well and the other at a plurality of measurement points down the well, and the output of the receiver is processed in a processing installation. The measurement points are divided into at least two groups, each of which comprises a plurality of measurement points spaced apart in a distance (D.sub.z) which is less than a predetermined limit distance so as to avoid aliasing, and the groups of measurement points are separated from each other by a distance (D) greater than the limit distance. In the processing installation separation of the down-going waves from the up-going waves belonging to the same group is carried out before coherence filtration of the separated waves.

Abstract: A rotary vortex separator for heterogeneous liquids, e.g. water with a small oil content on an offshore oil platform, includes injection channels (30) which inject water to be de-oiled at an axial speed relative to the periphery of the separator at the upstream end (4) of a cylindrical separation chamber (2) rotating about its axis (8). Purified water leaves from the other end (6) of said chamber via an annular outlet opening (26) of smaller radius to constitute a free vortex type of flow. The oil is removed by an axial tube (28).

Abstract: The invention relates to the setting-down of a pipe in the sea using a setting-down line. The line is provided with sinkers at its lower end portion which tension the line and allow a reduction in the angle of general inclination of the line with the vertical and thus a reduction in the length of the line.

Abstract: Hydraulic cement composition with delayed setting, intended to be employed in an environment which may be under extreme temperature, pressure and salinity conditions, the composition being characterized in that it incorporates(a) a saline or nonsaline aqueous liquid phase,(b) at least one hydraulic cement,(c) a setting-retarder adjuvant preserving and/or improving the rheological properties, a water-soluble copolymer resulting from the copolymerization of ethylenic acids, acrylamides and ethylenic esters of phosphoric acid.

Abstract: A safety valve for use in a hydrocarbon production tube comprises a valve member which is opened by a piston tube displaceable as a result of the intake of hydraulic fluid into an operating chamber therefor, and a tubular receptacle for receiving an auxiliary safety valve recoverable by means of a cable. The receptacle is longitudinally displaceable between inactive and active positions and is engaged telescopically with the piston tube in a sealed manner to define, with the piston tube, the operating chamber. The receptacle is normally retained in its inactive position by shearable elements, but after the elements have been sheared, descends to its active position simultaneously driving the piston tube to its lower position to open the valve member.

Abstract: A method of defining homogeneous rock formation zones along a borehole on the basis of logs, uses two logs, a lithological log and a log relating to the impregnation fluids. Individual limits of zones are determined by reproducing or reshaping each of the logs in the form of rectangular zones or crenellations, preferably rough crenellations for the first log and smoothed crenellations for the second log, and the individual limits are combined to obtain synthetic limits, some of the individual limits belonging to the first log only preferably being subsequently eliminated when the first log is smoothed.

Abstract: An internal chuck for use in the butt welding of tubes 16, 17 aligning the tubes and for bringing them into abutment comprises a central tube 6, a sleeve 7 slidable on the central tube and carrying centering means 12 and welding backup means 8, the centering means and the welding backup means being longitudinally spaced from one another, gripping means 2, and jaws 33 for clamping against the tubes. The jaws are displaceable longitudinally relative to the gripping means and central tube to draw the two tubes together and a jack 27 is provided for displacing the sleeve longitudinally relative to the central tube so that either the centering means or the welding backup means can be aligned with the ends of the tubes.

Abstract: The present invention concerns an assembly of pipes, particularly but not exclusively submarine pipes, adapted to permit disconnection of a tubular member therefrom while maintaining the interior of the remainder of the assembly isolated therefrom. The assembly comprises a first pipe provided with a first tubular connection portion for coaxial connection to a second tubular connection portion of a tubular member. The tubular member is also provided with a tubular extension which is coaxial with the second connection portion and houses a closure means. The end of the tubular extension is adapted to receive the casing of a manipulator for moving the closure means from the tubular extension into the first connection portion of the first pipe to isolate the first pipe from the tubular member and permit disconnection thereof.

Abstract: Apparatus for continuously recording, as a function of the depth, the residual magnetization of the rocks through which a well hole passes, comprising, on the one hand, a measurement probe which contains means for measuring the magnetic susceptibility and the magnetic field and, in a cryostat, three gradiometers and, on the other hand, a processing unit which incorporates an integrator (81) for carrying out integration of the data from the gradiometers, a multiplier (76) for multiplying the magnetic field by the magnetic susceptibility, and a subtractor (83) for deducting this product from the result of the integration.

Abstract: Apparatus for supporting a tubular element 24 to be butt joined horizontally at one of its ends to a tubular structure 27, comprises an upwardly acting, vertical hydraulic thrust jack 9 which compensates at least partly for the weight of the tubular element and which is placed towards the other end of the tubular element. The thrust jack is pivoted at its upper end on a slide 11 which is vertically movable and carries support members 23 for supporting the tubular element, and at its lower end on a base 6 mounted on a lower frame 2 provided with wheels 3 adapted to run on rails 4.

Abstract: An external apparatus for butting two tubular elements 1, 2 to be welded together comprises two frames 8, 9 provided with means for the external gripping of the elements and which are connected by jacks 10, 11 for bringing the elements together and by a plurality of connecting and aligning means 14-19 each comprising a pair of members 20, 21 engageable one in the other with the interposition of an elastic means 22. The gripping means comprise a plurality of radial jaws 55-64 for gripping the tubular elements and carried by support rings each comprising three jaw holders 23-25 each in the form of a segment of a circle.

Abstract: A machine for the internal butt welding of two tubes comprises a fixed axial electron gun, a rotary prism system for radially deflecting the electron beam and comprising a plurality of prisms and a deflection system for cyclically delivering the electron beam emitted by the electron gun successively to each of the prisms at a high frequency, the relative duration of utilization of each prism being modifiable in the course of the rotation of the rotary system.

Abstract: A consistometer container for testing rheologically evolutive materials is generally cylindrical or frustoconical in shape, and has a side wall composed of two half-shells 20, 21 which are connected together along two generatrices 40, 41 and which have externally threaded longitudinal end portions 26, 27. Two clamp rings 22, 23, are threaded onto the side wall ends to clamp the half-shells together. Such a construction enables the testing of a progressively hardening material without having to separate the material from the container as soon as the tests are finished.

Abstract: A geomechanical probe for a drilling well comprises a logging box located between two inflatable preventers and including a plurality of tracers movable radially and urged outwards by springs for engaging the well wall. The tracers are mounted on pistons which are received in cylinders and urged radially inwards by springs for retracting the tracers, the pistons being driven outwardly to displace the tracers into working positions abutting the well wall by supply of actuating fluid to the cylinders. The positions of the tracers is determined by differential transformers having cores fixed for radial movement with respective tracers.The preventers are inflated with pressurised fluid which is supplied thereto along passages in the probe which also supply pressurized fluid to the well space between the preventers to act upon the well wall.

Abstract: A control valve comprises a body having a fluid inlet and a fluid outlet and a rotary member provided with two separate internal passages, each capable of connecting the fluid inlet to the fluid outlet, according to the angular position of the rotary member in the said body. A control system is arranged in one of the passages for controlling fluid along the passage independent of the angular position of the rotary member, while the control of flow of fluid in the other passage is effected by adjustment of the angular position of the rotary member. The one passage is the main passage for normal use and the other passage is a secondary or by-pass passage for use when work is required to be done on the control system in the one passage. The control system in the one passage comprises valve members operated by a rod for closing seats in the passage.

Abstract: A process for deaerating water in an upright column immersed in a body of water and equipped at its lower end with an electrical pump which, essentially, provides the water lift in the column, comprises injecting into the upright column, at at least one injection point situated above the electrical pump, fine bubbles of an inert gas, for example purified nitrogen, under a pressure which is at most equal to the hydrostatic pressure in the column at the level of the injection point.

Abstract: A fluid transport line comprising coaxial inner and outer metal pipes, the inner pipe of which is intended to transport a thermally insulated fluid, is formed by successive sections, the inner and outer pipe portions of which are connected by means of metal rings interposed between successive sections in junction zones. To reduce the effect of the thermal losses thus created, a closed chamber containing a thermally insulating medium is defined round each junction zone by a metal shell which is welded to the outer pipe portions of the successive sections.

Abstract: In a process for purifying natural gas in which methanol is injected into the natural gas, the temperature of the mixture of natural gas and methanol is lowered to the absorption temperature, at which undesirable components present in the natural gas are absorbed by the methanol, and the natural gas thus purified is separated from the methanol, the natural gas is subject to a succession of purification stages, each of which incorporates methanol injection into the natural gas, circulation of the mixture at the absorption temperature, and separation of the natural gas from the methanol phase. The partially purified natural gas which leaves a stage other than the last stage enters the stage which follows it and the purified natural gas is obtained at the outlet of the last stage.

Abstract: A safety valve for installation in a well to close the passage for effluent therefrom comprises a valve body of generally cylindrical shape, shut-off element in a lower part of this body, and a cylindrical slideblock which is slidable longitudinally in the body and adapted to cause, in its descending movement, the opening of the shut-off element. A locking system for locking the valve in the well is located in a radially outer portion of the body and comprises a radially expandable attachment component for engaging, when expanded, in a stop groove provided in the receiving connection of the well surrounding the body. Upper and lower sealing elements for sealing against the receiving connection are arranged on radially outer regions of the body for forming between them a space for receiving a control fluid for the valve, the two sealing elements being arranged longitudinally one on each side of the locking system.

Abstract: A drill pipe joint for insertion in a drill pipe comprises a body having an axial bore therethrough and comprising generally cylindrical upper and lower portions and a widened cylindrical intermediate portion at the upper end of which at least three cutouts are formed for insertion therein of removable attached members each provided with an upwardly directed internal passage connecting the bore to an interchangeable nozzle mounted in the upper end of the passage and situated on a diameter intermediate the outside diameter of the intermediate portion and that of the upper portion of the body.The joint is particularly suitable for passing through a zone in which circulation is lost and is arranged in the drill pipe string above the level of the zone of lost circulation.