Patent GB-1313553-A (GB)
Title: Well apparatus and methods for installing and removing the same
IPC: E21B43/013
Filed: 1970-10-19
Abstract: 1313553 Wells &c VETCO OFFSHORE INDUSTRIES Inc 19 Oct 1970 [12 Jan 1970] 49521/70 Heading E1F [Also in Division H2] Apparatus for conducting electric current to a device such as a submersible pump 10 in a well bore, includes a first electric conductor 52 extending from the pump to a landing head 53 supported at the top of the well bore, and a second electric conductor 81 extending from a power source to a plug device 100 which is movable toward the landing head 53 to effect connection between terminal portions of the conductors 52, 81. The plug device comprises a sleeve 76, Figure 3, non-rotatably slidable in a side arm 73 of a production head 43, by a nut 100 turned by a diver. The sleeve 76 contains one or more electric conductors 80 of the cable 81, each terminating in a male plug member 79, and supported in a matrix 82 of insulating material. The sleeve cavity 63 is initially filled with a high dielectric silicone grease. The cable 52 terminates at its upper end in one or more conductors 58 each having a socket 62 adapted to receive a respective plug member 79 on movement of the sleeve towards the landing head to complete the electrical connection. The silicone grease is expelled during this movement through a check valve 95. The sleeve 76 may be withdrawn into the arm 73 when it is desired to break the connection and retrieve the landing head, cable and pump, by rotating the nut 100 in the reverse direction. The apparatus is applied for use with an underwater well having concentric casings 19, 23, 11 supported on hangers 18, 21 and 24 respectively, the production head 43 being coupled to the hanger 21 by a connection 32. The casing 11 extends through producing zones 12 and has perforations 13 to admit the production. The landing head 53, cable 52 and pump 10 form a unit which is run into the well through a production riser 50 on a wireline tool, the pump landing sealingly on a seat 15 in the casing 11, and the landing head on a support shoulder 54 in the production head. Correct angular alignment between the landing head and the side arm 73 is assured by a radial pin 74 co-operating with a helical cam 75. Once the connection between the cables 52, 81 has been effected, the production is pumped out of the well through the casing 11 and a flow line 45 controlled by a valve 47. When it is desired to retrieve the pump, the electrical connection is broken and the sleeve 76 withdrawn into the side arm. The wire line tool is engaged with a fishing head 69, and the landing head, cable and pump lifted out of the well. If the pump is jammed in the casing 11, for instance by being sanded up, a frangible connection 51 between the cable and the pump gives way, and the pump is retrieved separately using a fishing jar. In a modification, Figure 5a, 5b (not shown), the pump is supported in a tubing string within and packed off from the casing 11, so that if the pump becomes jammed through sanding up it may be retrieved by lifting the tubing string out of the well. In an alternative embodiment, Figures 6, 7, the landing head is replaced by a tubing hanger 302 supported on a shoulder 303 in the casing hanger 24 and releasably retained by a bevelled latch ring 304, and angularly aligned in the casing hanger by a spring loaded key 343 engageable with a keyway 344. The tubing hanger supports a tubing string 200 containing the pump 10, and the cable 52 extends upwardly to a support member 310. The cable terminates in conductor(s) 58 having plug member(s) 318 in an insulating matrix 315 and adapted to mate with socket(s) 79 on conductor(s) 80 of a cable 340, which are mounted in an insulating matrix 321 in a housing 319 carried by a connector 325. The connector is lowered on guidelines and telescopes over the casing hanger 21 to effect connection between the socket housing 319 and the plug support member 310, silicone grease being expelled from a civity 365 through a check valve 366. The cable 340 is joined to the cable 81 (not shown) by a fitting 341. The pump is retrieved by releasing the connector 325 and elevating it to the drilling vessel, and lowering a retrieval tool into engagement with the tubing hanger, exerting an upward pull to release the latch ring 304, and lifting the tubing hanger, pump and cable to the surface. The procedure for drilling and casing the well, which is stated to be known, is described.