GB1378510A - Derrick for erection on board a drilling ship - Google Patents

Abstract

1378510 Boring earth &c GROUPEMENT POUR LES ACTIVITES ATOMIQUES ET ADVANCEES 14 Dec 1971 [15 Dec 1970] 58120/71 Heading E1F In a derrick, substantially vertical pipe stands are moved to, or from, the drilling axis from, or to, a transfer device. Apparatus for moving the stands on a drilling vessel comprises a unit 300 having jaws 20 on an arm 31 carried by a turntable 32 mounted on a frame 34 fixed to the derrick; a unit 200 having jaws 20 mounted for vertical movement on the vertical limb of a cranked member 21 mounted on a turntable 22 carried by a carriage 23 reciprocable on a frame 24 fixed to the derrick; and a unit 100 having jaws 10 mounted on an arm 11 on a turntable 12 carried by a carriage 13 reciprocable on a frame 14 fixed to the derrick. The jaws of the units 100, 200 are initially at a rest position 75 and are moved by rotation of their turntables to position 71. From the position 71 the jaws are advanced by their carriages 13, 23 to engage and close upon the stand which extends above the drill pipe in the well. The stand is unscrewed from the rest of the drill pipe after the lower end of the stand is supported by the unit 300. The jaws 20 are raised to engage a joint in the stand after which the stand is moved by the jaws 10, 20 to the position 73 by rotation of the turntables. The carriages 13, 23 are operated to advance the stand to the position 74 between guides 65 on a pipe transfer device. The jaws of the transfer device are closed on the stand, the jaws 20, 10 are opened, and the jaws of the units are moved back to the position 75. The stand is moved by the transfer device to a horizontal storage position. The jaws 30 of the unit 300 are used only when drill collars are being moved.