GB1201471A - Connector for underwater pipelines - Google Patents

Abstract

1,201,471. Pipe couplings; supporting underwater pipes. CAMERON IRON WORKS Inc. 2 Oct., 1967 [10 Oct., 1966], No. 44826/67. Headings F2G and F2P. Apparatus for coupling together sections of underwater pipe-line, particularly where one or more pipe-lines 14b, 15b together with control lines 23b, 24b, 25b, 26b (Fig. 3) are to be connected to a well head 12 via a looped section 14a, 15a which has previously been joined to the Christmas tree 11, comprises means for supporting recessed hubs 18, 20 at the adjacent ends of the pipe-line sections so that relative movement can occur, e.g. as is allowed by the loop formation of the section 14a, 15a and means adapted to lower a connecting body 42 into a position between the hubs, and by means of a remotely operated device cause relative movement between the hubs 18, 20 so that the body 42 enters the recesses in the hubs to couple the pipe-line sections, whereupon the coupling is secured by clamping means which may also be remotely operated, the first-mentioned device being releasable so that the connector body may be removed from between the hubs. The lowering means comprises a tool which incorporates the device for causing relative movement between the hubs and also the clamping means. Preferably, a separate raising tool (Fig. 9, not shown) is used when the connector body is to be removed, the lowering tool being raised to the surface, following completion of the clamping of the connected hubs, by members 60, 61 (Fig. 7, not shown). The lowering and raising tools are in fact identical except for a slightly different arrangement for rotating a screw-and-nut actuating mechanism 64, 65 which operates the further device, whereby rotation of the suspension member, viz. drill pipe 77, in the same direction is used in the former to close the clamping members 60, 61 and in the latter to open the clamping members. The screw 64 is journalled in member 60 and the nut 65 in a yoke 66 carrying the member 61, and in the lowering tool shown the nut is prevented from rotating by a key 80 engaging groove 65b in the nut, the screw 64 being rotated by a key 78 engaging a groove 79 in the screw, whereas in the raising tool the nut is rotated while the screw is held fixed. A member 76 carrying the key 78 is attached to the drill pipe 77 and is rotatable in a frame 70, 71 carrying the first-mentioned device which comprises a pair of cylinders (50, 51, Fig. 4, not shown), extending between and welded to the frame members 70, 71, and a pair of yokes 46, 47 carried on the ends of pairs of piston-rods (Fig. 5, not shown) which are extendable from opposite ends of the cylinders, the yokes being adjacent the frame members 70, 71 when the piston-rods are retracted and spaced beyond the frame members 70, 71 when the piston-rods are extruded. Fluid is supplied and returned reversibly through a pair of conduits via bores in the yoke 47 and in one of the piston-rods associated with each cylinder, for this purpose. The yokes have slots 46a, 47a which engage reduced-diameter portions of the hubs 18, 20 when the tool is lowered from the water surface, the piston-rods being extended at this time and the hubs, which are supported respectively in a sleeve 32 fixed to the well head and by pins 40a, 40b in a pair of slots 38a, 38b in a fixed bracket 38, being held apart a distance greater than the length of the coupling body by a compression spring (36) arranged within the sleeve 32 and acting on a flange (35) of a tubular extension (34) of the hub 18. The tool is guided into position to engage the yokes with the hubs by a pair of anchored cables 17c (17d) terminating in rods 19c, 19d, which co-operate with bellmouthed sleeves (110), (111) on the frame. Following engagement of the yokes with the hubs, the cylinders (50), (51) are actuated to retract their piston-rods and so draw the yokes towards the frame members 70, 71, thus moving the hubs up to the connector body, which up to this point has been constantly supported in the tool at the correct height by the engagement, within slots (44a), (44b) in arms (43a), (43b) integral with a ring 43 surrounding the body, of key formations on rods (45a) and (45b) which are respectively secured to the yokes 47 and 46. As the connector body is being received by the hubs, these key formations move out of the slots (44a, 44b) so that, following subsequent operation of the clamping members 60, 61 to secure the coupling, the tool may be raised up to the water surface. The actual joints between the various passages in the coupling body which co-operate with corresponding passages in the hubs 18, 20 to connect the various pipe-line and conduit sections comprise nipples 84, 90, 91 (Fig. 8, not shown) which are threaded into counterbores in the body 42, seals (85), (88) on each nipple, an isolating ring (93) surrounding each of the main fluid passages, and a seal (95) in a conical surface 104b of the body, each hub having corresponding recesses and surfaces to mate with the coupling body and ensure smooth guiding into exact alignment, the latter being assisted also by grooves 106a, 106b, Fig. 3, in the periphery of the body co-operating with keys 105a, 105b in the hubs..