GB1430530A

GB1430530A - Drilling apparatus

Info

Publication number: GB1430530A
Application number: GB1934574A
Authority: GB
Original assignee: Jacobs Associates
Current assignee: Jacobs Associates
Priority date: 1974-05-02
Filing date: 1974-05-02
Publication date: 1976-03-31

Abstract

1430530 Boring earth &c JACOBS ASSOCIATES and K M WILLIAMSON 2 May 1974 19345/74 Heading E1F A method of drilling for deep formations from a drilling location at the surface which is horizontally remote from the bottom of the hole to be dug includes the steps of storing a plurality of long drill rods 41 horizontally, thrusting a first drill rod into the earth slanted only slightly downward from the horizontal, drilling at the remote end 43 of the drill rod a hole which slopes downwardly and then curves to a substantially vertical direction as drilling progresses, and sequentially joining additional drill rods at the drilling location and thrusting each additional drill rod into the hole as drilling progresses. As described the drill rods 41 are thrust into the earth by a gripper device 42 mounted on a carriage 36 which moves down inclined rails 38 by gravity, the carriage 36 being returned to the top of the slope by a winch 39. The gripper device 42 may rotate the drill string to perform the drilling. Alternatively the drill string is not rotated, the end of the string being provided with a downthe-hole turbine motor powered by drilling mud passing down the hollow drill string. The drill rods 41 are stored in pipes 46 placed in fixed racks 48 and a movable rack 49 (Fig. 4). The rack 49 can be moved transversely by rams 53 and vertically by rams 58 to bring the end of each pipe 46 into line with the gripper device 42. Drilling mud is pumped from a mud pit 61 by pump 62 along conduit 63, into T-piece 64 where it flows along the space between the pipe 46 and drill rod 41. Each pipe 46 is provided with an end cap 47 so that the mud then flows along the hollow drill rods 41 down to the end 43 of the string. The mud then flows back up the bore and through T-piece 33 and conduit 68 back into the mud pit. So that the mud in each pipe 46 is not lost, the pipes 46 may be provided with gate valves 77 (Fig. 5a) which close off the ends of the pipes 46 after the drill rod 41 has been removed.