Well sinking as shaft and sealed-off pipes lowers shaft then walled and bottom-sealed to make filled flow structure whose drilled pipe run is parted from walls and raised to run sealably pluggable pipes off both sides.

摘要

The shaft (11) is sunk, walled and closed off by bottom plate and fitted with an inserted guide structure which is drilled out and filled to take a pipe string. The filled structure is then freed from the wall openings and the pipe structure parted to allow structure, its filling and the pipe length inside the structure to be surfaced. The pipe ends (15,16) then parted are now sealed from within the shaft (11) and fitted with shutoffs. The drilling method starts and ends in shallow pits (19 and 20) assisted by a pilot bore and wash-out bore, first using the drill string to form the pipe in the drilled bore. The two pipes (15,16) are wire-coil filtered (17,18) less than 5 m from the shaft walls.