Abstract: A method for obtaining a model of a surface including the steps of obtaining measurements of geometrical data concerning specific points on the surface, making a grid of the surface, with the grid passing through said points, memorizing, at an address which is specific to each node of the grid, the coordinates of the node, the number of satellites of the node, information for access to the addresses of said satellites and thereafter to information which relates to them, and geometrical data which may be associated with said node; for each node, defining a local roughness index obtained from a weighted sum of the current coordinates of the node and its satellites, defining the sum of an overall roughness index representing the sum of all the local roughness indices, and of an overall index of the infringement of said geometrical data, iteratively adjusting the coordinates of indefinite nodes, by using at each adjustment the sum of a weighted combination of current node neighbor coordinates and of a combination

Abstract: A rectifier for establishing a flat fluid flow velocity profile in a pipe 16 is composed of a bundle of cylindrical tubes 12 of the same diameter and length, assembled to form a cylindrical block 10 having a diameter equal to the interior diameter of the pipe and having a honeycomb section. The interstices 18 remaining between the tubes of a median ring r.sub.2 are filled with a suitable filling material, while those 20 between the tubes of an outer ring r.sub.1 and those in a central zone r.sub.3 of the rectifier are left open.

Abstract: The invention relates to a process and a device for measuring the gelling of paraffin petroleum products, in particular, crude oil. The process involves: measuring, with respect to the temperature and over a given thickness, the propagation velocity and the amplitude of an ultrasonic wave in the crude oil being analysed; then determining the transition temperature T.sub.t, at which a sudden change in the thermal variation in the inverse of the propagation velocity is observed; determining the ratio of the slopes for the propagation velocity inverse obtained between the linear parts of the thermal variation of said propagation velocity, around said brake point corresponding to T.sub.t, above and below, respectively, the determined temperature T.sub.t ; determining the ultrasonic signal amplitude difference .DELTA.A between the temperature T.sub.t and a given lower reference temperature, for example T.sub.t -5.degree. C.

Abstract: This invention relates to a lightened gas-impermeable cement grout which comprises hydraulic cement, water, silica fumes in an amount of from about 5 to about 65 weight % based on the weight of the cement, and at least one polyethylene imine having a molecular weight of between about 600,000 and about 1,000,000 in an amount of from about 1 to about 25% weight % based on the weight of the water.

Abstract: A well probe including two offset shoes fixed outside of a tubular column and an intermediate shoe provided with a central passage having a cross section larger than a cross section of the column. The intermediate shoe is connected to a lower offset shoe by a mobile hasp. A mobile harness is adapted to be moved into and out of a lateral cavity of the intermediate shoe for enabling coupling and uncoupling of the intermediate shoe with a wall of the well. The mobile harness includes a casing for accommodating sensors and a hydraulic triggering arrangement, with the sensors and the hydraulic triggering arrangement being connected to a surface installation by cables and an electronic cartridge.

Abstract: The invention relates to a method for marine seismic prospecting, of the type in which a seismic wave is emitted at a determined point close to the surface of the water and the waves reflected by the interfaces between geological formations of the subsoil are recorded as a function of time using receivers arranged at a plurality of locations close to the surface of the water. A mathematical model of multiple signals and peg legs is produced from known wave equations. Data calculated using the mathematical model M(t,x) are adapted with polynomial transfer functions and are subtracted from the data recorded by each of the sensors in order to obtain final data. Using the final data, a graphic representation is prepared of the geological formations of the subsoil in which the seismic wave is propagated.The invention proposes mathematical processing of the data enabling the elimination of multiple signals and peg legs.

Abstract: A method and device for detecting inversions of the earth's magnetic field by taking measurements in a drill shaft. The device includes a first probe used to measure the magnetic induction B.sub.1 during its movement in the shaft, a sensor to measure magnetic induction B.sub.2 on the surface of the ground at a stationary point at the same time as B.sub.1 is measured, a second probe to measure magnetic susceptibility X of the rocks as it moves through the shaft, and a data-recording and data-processing unit. The data-recording and data-processing unit further includes a device for calculating a value of B.sub.1 -B.sub.2, filtering the calculated value to isolate the induction fraction B.sub.L, which is only composed of a component B.sub.I resulting from an induced magnetization, and the component B.sub.R resulting from the residual magnetization. The induction B.sub.I based on the induction B.sub.1 in the shaft and on the magnetic susceptibility X can be calculated.

Abstract: The process for measuring the coefficients of adhesion and friction of a drilling fluid involves, following the standardized filtration of the drilling fluid or mud from which a solid phase "filtration cake" and a liquid phase or filtrate collected on the downstream side of a filter 15 are obtained, placing a metal piston skirt 29 in contact with a filtration cake in the presence of a contact pressure, and measuring the moments of adhesion and friction when the skirt is driven in axial rotation perpendicular to the contact surface, and the axial extraction or contact adhesion force when the skirt is withdrawn after a determinate period of contact.

Abstract: Process for treating an aqueous solution of acrylamide resin, characterized in that an emulsifier which is preferably nonionic or anionic, a solution of initiator comprising an organic peroxide, preferably a diperoxide, and optionally a solution of a retarder preferably consisting of a phenol derivative or an alkali metal inorganic derivative are added slowly and with stirring, preferably in the form of a pre-emulsion, to an aqueous solution of acrylamide resin monomer.

Abstract: The invention concerns a compound cement containing cement and a blast-furnace slag, more particularly for bore holes.This compound cement is characterized in that it comprises the following components:a Portland cement presenting, by weight, a magnesium oxide content of max. 6%, a sulphur trioxide content of max. 3%, an insoluble residue of max. 0.75%, a tricalcium silicate content between 48 and 65%, a tricalcium aluminate content of max. 3%, a total amount formed by the amount of tetracalcium aluminoferrite, plus the amount of dicalcium ferrite, plus two times the amount of tricalcium aluminate which is at most equal to 24%, and a total amount of alkalies, calculated as sodium oxide equivalents, of max. 0.75%.and a ground blast-furnace slag with a vitrification rate of 90 to 100%;these two components presenting a similar mesh size, comprised between 2,800 and 3,000 cm.sup.2 /g, and being mixed together in the following wt-% proportion: 50 to 10% of Portland cement and 50 to 90% of ground slag.

Abstract: A drill string has a bulge equipped with a system of n injection ducts connecting the interior of the string surrounding annular space and opening upwardly into the space to divert a part of the drilling fluid supplied to the bit. This arrangement makes it possible to produce below the bulge a pressure decrease H markedly greater than 10 meters of water by setting the flow of drilling fluid in the system of injection ducts at a value, expressed in m.sup.3 /s, equal to approximately: .sqroot.10H.times.S.times.s33 n, S and s being the cross-sections, expressed in m.sup.2, respectively, of a part of the portion of the annular space included between the periphery of the bulge and the drill string and of the group of n injection ducts.

Abstract: A metallic coating (20) is produced on a non-weldable inorganic substrate (6) by hot-spraying on a hot-sprayed intermediate layer (19) of refractory metal alloy chosen from nickel-chromium alloys and nickel and titanium aluminides. This intermediate layer itself may be deposited on an undercoat (18) of a ceramic chosen from aluminium and zirconium oxides and titanium hydrides, which is formed by hot-spraying on the inorganic substrate (6).

Abstract: A method for recycling gas in an installation for the stabilization of crude oil (1) containing gas/liquid separation stages (2, 3, 4) whose gas removal pipes (12, 13, 14) are connected to the intake of a gas treatment installation (18) which provides a current of rich gas (19) and a current of poor residual gas (20), characterized in that an adjustable part (21, 22) of the poor residual gas current is injected into the flow of crude oil (8), preferably between the penultimate (3) and last (4) gas/liquid separation stage, of the installation for stabilization of crude oil (1), in order to increase the production of liquified petroleum gas and condensates.

Abstract: A drill string stabilizer includes a cylindrical sleeve 11 coaxially surrounding a central tubular element 10 and fixed thereto by a plurality of helical blades 17 extending between the facing surfaces of the sleeve and the element. Converging truncated cones 13, 16 are provided on both ends of the sleeve. The upwardly flowing drilling mud establishes an annular fluid bearing between the sleeve and the borehole, while the helical blades implement a pumping function to enhance the discharge of the mud and cuttings.

Abstract: An immersible electrical coupling includes a fixed connector (2) mounted on the wall (1) of a device, and a cable terminal (6) engaged with the connector. An outer molding of synthetic resin (33) surrounds tubular metal components (16, 12, 8, 10, 9) of the terminal, and a concentric inner molding 32 isolates the outer and inner sheaths (13, 17) of the cable (7). Within the terminal (6), the insulated conductors (19) which emerge from the end of the cable are spaced from one another, and traverse an insulating sealing plug (20) inserted in a watertight manner inside the tubular metal components (8, 9).

Abstract: A servicing apparatus for installing a piece of equipment horizontally on a submerged unit and for removing it therefrom, comprises a movable servicing module designed to engage on the upper part of the submerged unit, pivot thereabout and lock against it in a horizontal position, and a cradle supporting the piece of equipment. The cradle is carried, by means of connections allowing transverse adjustment, by sliding supports mounted in the servicing module, and movable longitudinally by means of jacks. Mutual engagement means are provided on the submerged unit and on the piece of equipment to ensure that the latter is positioned accurately on the unit.

Abstract: A consistometer usable at a work site comprises a stationary receptacle (9) which is placed in an enclosure (3) defined by a consistometer casing (2) and is provided with a stirrer (17) with a rotary drive spindle (18). The casing has an extension (20) in which there is arranged an intermediate shaft (23) angularly fast with a torque receiver (22) of a magnetic type actuated from outside the extension by a driven torque transmitter (21). Shaft (23) is angularly fast with a coupling device (24) for engagement with the spindle simply by the spindle being introduced into the coupling device when the receptacle is placed in the casing.

Abstract: An annular safety assembly comprising, between an upper cylindrical body and a lower cylindrical body, through which connecting tubes of production tubes pass, a packer and a low-bulk anchorage system consisting of a radial spacing ring, a resilient anchorage ring split along a generatrix and provided with peripheral anchorage teeth and a thrust ring which can be moved upwardly by thruster-plungers extending from the lower cylindrical body to apply the anchorage ring to the casing, and a safety valve arranged separately from the connecting tubes, which extend between the said cylindrical bodies, and below the lower cylindrical body.

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: 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.