GB1049926A - Improvements in and relating to submarine coring apparatus - Google Patents

Abstract

1,049,926. Boring earth &c. INSTITUT FRANCAIS DU PETROLE, DES CARBURANTS ET LUBRIFIANTS. Jan. 16, 1964 [Jan. 17, 1963], No. 2058/64. Heading E1F. Submarine core drilling apparatus comprises a bit 4 surmounted by a coring tube 2, a bit drive motor 1, a pump 5 supplying drilling i fluid to the bit through a flexible tube 6, and a float 10 to maintain the apparatus vertical. The apparatus is lowered into position by a cable 9 supplying electricity to the motor which has rotor. extension 8 connected to the bit. The float may be combined with the pump which carries a gauge S indicating the, depth drilled. The apparatus is steadied by a tripod 12' which may mount the apparatus shown in Fig. 10 for resisting the drilling torque. Rollers 57...60 are spring loaded to engage the flexible tube and rotate as drilling proceeds to give an indication of the depth drilled. The coring tube 2 is formed as an extension of the motor stator which has a central passage for drilling fluid, the top of the tube 2 having holes to permit the fluid to flow in the annulus between the tubes to the bit. The lower end of the tube 2 shown in Fig. 4 is closed by a piston 20 which prevents silt entering the tube, the piston being fixed to the bit by a bayonet lock during rotation in one direction through the silt, and being freed during rotation of the bit in the other direction for coring. The tube 2 has a guide 37 and houses a core holder 35. In a modification (Fig. 7) the piston is prevented from retracting during passage through the silt by an adjustable valve, 44 which prevents water from leaving the tube until the coring pressure is reached. In a furthermodification (Fig. 8) a slidable sleeve 51 having holes 50: permits the supply of drilling fluid tothe interior of the lower part of the tube during the initial stages of coring, the sleeve being engaged by spring catches 51a, 51c.