GB985370A - Underwater wells - Google Patents

Abstract

985,370. Boring earth etc.; wells. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. Sept. 26, 1963 [Sept. 28, 1962], No. 37993/63. Heading E1F. A pipe connection is formed between a vessel 11 at the surface of a body of water 12 overlying a formation 13 and a hole 26 in the formation by lowering a pipe string 27 from the vessel until its lower end is adjacent the formation, moving the string until its lower end is above the hole, and lowering the lower end into the hole. The lower end of the string is closed, has a jet aperture 29, and slidably carries a frame 31 supporting a remotelycontrolled television camera 33 having lights 34 and connected to a viewing screen 37 on the vessel. Drilling or other fluid pumped down the string issues from the aperture to deflect the lower part of the string from the vertical whilst the string is slowly rotated. When the hole is shown on the screen the string is lowered into the hole to form the connection, the camera is hauled up the string, and a conductor pipe (not shown) is lowered about the string into the hole. In a modification the lower end of the string 51 (Fig. 4) is formed by a conductor pipe 54 having a jet aperture 57 and carrying the camera 33 and lights 34 which are attached by electro-magnets 58. After the hole appears on the screen the conductor pipe is entered into the hole, the camera and lights are removed, and the pipe is lowered into the hole to complete the connection. The pipe is cemented into the hole by pumping cement down the string and through the aperture, the string being disconnected when the cement sets. The hole is continued by drilling through the bottom of the conductor pipe with a bit 25a (Fig. 8) mounted on a string 21 which may be positioned in the hole by the method according to the insertion, the bit having its lower end closed by a plug 64 during positioning so that fluid is discharged through a jet aperture 60. During drilling the plug is removed, the aperture is closed by a spring pressed sleeve 61, and fluid is discharged through ports in the bit. Instead of locating the hole by means of the television camera, the hole may be located by trial and error the motion of the waves providing the up and down movement of the string as the lower end is deflected from the vertical. Specification 873,479 is referred to.