GB1133741A - Improvements in and relating to drilling of earth formations - Google Patents

Abstract

1,133,741. Pipe joints. BECKER DRILLING (ALBERTA) Ltd. 18 Jan., 1966. No. 2206/66. Heading F2G. [Also in Division E1] Boring apparatus comprises a percussion hammer 26, Fig. 1, engaging an anvil cap 29 mounted on a rigid tubular drill pipe 30 which carries an annular cutting bit 36, Fig. 2. Pipe 30, Fig. 4, has upper female and lower male end fittings with complementary tapered threads and supports tube 130 forming annular chamber 55. Ports and passages 63, 64 in fitting 61 and ports in the male fitting provide for interconnection of the chambers 55 of adjacent pipes when joined together by the threads. Fluid under pressure is supplied from pipe 96 down the chambers 55 into passages 47, 48 in the bit which has radial teeth 42 separated by tapered walls forming cutting edge 45. The bit cuts large pieces which are moved up the central bore of the drill string and out through pipe 89. The apparatus is mounted on a vehicle frame 12 which also carries apparatus for raising the pipe string. This latter apparatus consists of a ground engaging plate 100, Fig. 8, mounting hydraulic jacks 102 from the piston rods 104 of which hangs a cradle 108, 109 carrying plates 110. Both plates have aligned holes through which pipe 30 extends. Arms 111 secure the apparatus to the frame 12. When it is required to raise the string, slips 116 are applied to the pipe in the hole in plate 110 which is then raised by jacks 102 to lift the string. When the string is otherwise supported, the jacks are retracted. Repeated extension and contraction ratchets the string out of the bore.