Abstract: In the automatic positioning of the end of an underwater flow line, particularly in deep water, on a base, the end of the flow line is lowered to a position adjacent a connecting sleeve. The end of the flow line is connected to a hauling cable extending through the sleeve and a pull is exerted on the cable to draw the end of the flow line into the sleeve. The sleeve is detachably mounted on positioning apparatus mounted on the base and pivotable relative thereto in azimuth and elevation to align with the flow line. When the end of the flow line has been received in the sleeve and locked thereto, the sleeve is positioned on the base, locked thereto and released from the apparatus which is withdrawn.

Abstract: The invention relates to a tool which incorporates a device insuring the efficient control of a percussive hammer, regardless of the drilling depth. For this purpose, drive sludge arriving in an annular space reaches an inlet of a fluid switching element of single or double stability in which the flow of fluid alternates between two fluid circuits, causing the hammer to strike and return.

Abstract: The invention relates to an automatic device for coupling pipe means having means to bring together and align the axes of the pipe means to be coupled.A stiffener 46 supports one end of a helical and semi-rigid coupling tube 20, at points 47, 48 spaced along which are articulated respectively the rod 51 of a jack 50 and the base of the jack. At the end of travel relative movement toward one another of manifold 52 and well head 1, the axes of the end 12 of fixed collector 19 and of the end 11 of pipe 20 come into alignment under the deformation of pipe 20.The device is applicable to pipe means with their axes vertical or horizontal and is particularly suited to the coupling collectors to well head manifolds in underwater petroleum wells.

Abstract: Electrical insulation for an elongate current carrying body, e.g. an underwater cable for carrying very high voltages, is provided by winding a tape round the body under tension, the tape being made of a film of an axially orientated polymer having a thickness less than 200 microns, and preferably between 10 and 50 microns, a significant degree of crystalline order, a high tensile strength, a high modulus of elasticity, and the ability to cling to itself.

Abstract: For holding the end of an immersed suspended elongate member, e.g. a flow line or flow line bundle for a well, in a constant direction in spite of changes in the direction of the surface retaining means, e.g. a ship, from which the elongate member is suspended, the upper end of the member is secured to a trolley secured to a slide which is mounted on rollers movable on circular rails coaxial with the upper end of the member. The slide is rotatable about the axis of the rails and is rotated to compensate for any changes in the direction of the surface retaining means.

Abstract: In the measurement of the distance between two immersed points using ultrasonic signals, a control beacon is located at one point and a servo-beacon at the other point. The control beacon emits a first signal which is received by the servo-beacon. After a set period of time T sufficient for the disappearance of all echoes, the servo-beacon emits a signal which is received by the control beacon. Measurement apparatus associated with the control beacon determines the distance as a function of the time between emission of the first signal by the control beacon and reception of the signal from the servo-beacon, and the velocity of the ultrasonic signal which is determined in the region of the control beacon.

Abstract: In a method of welding together two submerged pipe ends, the pipe ends are spaced apart and introduced through orifices into a receptacle by which they can be isolated from the surrounding medium. The spaced pipe ends are connected by a connection sleeve and after isolation are welded to the connection sleeve.

Abstract: In a production well-head for an underwater oil well the suspension head of the innermost tubing, which has a frusto conical surface on which the production tube suspension member seats, has a duct leading from the enclosed space between the innermost tubing and the tubing adjacent thereto, to the interior of the innermost tubing, and a duct communicating therewith is provided in the suspension member.

Abstract: In drilling a hole using reverse circulation and the Venturi effect, drilling fluid is caused to flow through the annulus between the set of drill pipes and the hole and to rise under reduced pressure in the interior of the drill pipes to a level at which it is ejected outside the drill pipes, using a fluid diverting device connected in the set of drill pipes and which includes a Venturi tube, the device causing ejection of the fluid from the interior of the pipes, drilling fluid being pumped from the surface in the interior of the drill pipes to the device in which it is diverted into the Venturi tube to cause upward flow of fluid from the drill tool.

Abstract: Butt-welding apparatus for welding two pipes, e.g. for the shipboard welding of a laid pipe and a towed pipe, comprises a frame for receiving the pipe ends, means for securing the pipe ends relative to the frame and compensation means for causing movement of one pipe relative to the other to compensate for any shrinkage caused by the welding operation and by preheating the pipe ends to be welded.

Abstract: In the welding of tubes with bevelled ends without heels or root-faces, all the weldings beads are made from the outside of the tubes with the tubes being in contact with local gap not exceeding 2 mm. The first and second welding beads are made both by the up-hill method and the down-hill method with the axis of the welding torches at the same inclination to the normal or the radius of the pipe and the accuracy of welding is improved by the use of mechanical guiding means for the welding means comprising at least one roller which bears on the bevelled ends of the tubes adjacent the welding zone.

Abstract: A drilling tool comprising a body having a leading face with a central recess providing the body with an annular leading cutting edge such that during drilling a central core is formed, and a central cone positioned axially in the recess for breaking up the core.

Abstract: The invention relates to the balancing of the pressures in drilled strata, the pressures being lower than that of the liquid columns contained in the entire well.The hydrostatic level of fluid, e.g. a liquid, in the bottom of the well is selected to obtain the balance and the fluid is caused to flow, to additionally serve as a drilling fluid, by separating the fluid into two columns, communicating at either end, between the tubing of the well and a set of rods therein and within the set of rods, and injecting a fluid of lower density into the upper part of one of the columns.

Abstract: A fire extinguishing apparatus particularly but not exclusively for protecting large areas comprising a reservoir for a fire extinguishing fluid under pressure connected by a normally closed differential valve to a plastics tube which traverses the area to be protected, the tube being filled with air and/or an inert gas under pressure and being adapted to burst when exposed to a predetermined temperature, bursting of the tube and the consequent sudden decrease in pressure in the tube causing opening of the valve to allow the extinguishing fluid to flow from the reservoir along the tube to the region of the burst.

Abstract: A riser column particularly for use in deep water comprises a central tube connectable by its lower end to a submerged installation, for example a well, and including means permitting the central tube to oscillate relative to the installation, and connected at its upper end to a suspension table associated with a surface support, for example a platform, and bearing support means intermediate its ends at a level below that at which waves are effective, and a plurality of satellite tubes arranged around the central tube, each satellite tube having a bottom part extending from the intermediate support means to the submerged installation and a removable top part extending from the support means to suspension table and releasably connected to the bottom part thereof for withdrawal from the column following disconnection of the column from the installation, for example, in the event of a storm.

Abstract: An electrical connector for effecting connection between groups of submerged electrical contact elements comprises a plug and a base, each provided with electrical contact elements to be connected and which are immersed in an insulating liquid in respective enclosures in the plug and base, one of the enclosures being annular and inwardly limited by an inner protective body and the other of the enclosures being cylindrical and outwardly limited by an outer protective body. The plug and base are connected by sliding the cylindrical enclosure over the surface of the annular enclosure so as to replace the inner protective body by the cylindrical enclosure and to bring the electrical contact elements into alignment.

Abstract: An underwater excavation system comprises an excavating implement suspended from a surface support by a carrying line and means for moving the implement horizontally between an excavation site and a spoil dumping site comprising a guide line cooperating with the carrying line and extending from the surface support to a mooring on the sea bed.

Abstract: In a positive or negative heat transfer system with an intermittent source of positive or negative thermal energy, utilization means and a reservoir of heat transfer fluid flowing between the reservoir, the source and the utilization means, the reservoir is divided into two compartments of complimentarily variable volume and excess positive or negative thermal energy not required by the utilization means is used primarily to maintain the enthalpy of the fluid in one of the compartments of the reservoir at a maximum (for positive heat transfer) or mininum (for negative heat transfer) level, the volume of that one compartment being maintained at or reduced to a minimum until the required level of enthalpy is attained.

Abstract: The invention is directed to a method and apparatus for considerably reducing the risks of collision between cargo and ship during transfer of the cargo at sea. For this purpose, there is created in a short interval of time a sufficient space between cargo 7 and the ship by lowering of the upper part of a support 16 at the moment T.sub.2 when cable 5 lifts the cargo from the support. The invention also applies to transfer of cargo from a wharf.

Abstract: A system for welding the ends of submerged pipes in a gaseous atmosphere at any depth comprises isolating the ends of the pipes by introducing obturators therein and then introducing the pipe ends into an open topped receptacle which is capped with an underwater personal carrying intervention unit. The closed receptacle is filled with gas and then a sleeve is positioned between the ends of the pipes and welded to the pipes.