Displacement piledriver has vibrator downhole part of drillpipe as flexibly joined to surface part carrying drillpipe reciprocating rotation motor plus concreting pipe right through pipe.

摘要

The downhole end (2) of the drillpipe (1) contains a vibrator (3) and is held by a flexible joint (5) which permits deflection at an angle to the drillpipe and at the same time transmits tensile, compressive and rotary moment and in this way keeps the upper part of the drillpipe free of vibration. The drillpipe derives rotation from an up-and-down drive motor (17) on the surface part of the pipe. The feedline for the vibrator motor runs through an hydraulic guide (12) on the surface part of the drillpipe with fluid or gaseous media or again through a slipring type swivel (13) in the case of electric drive. A concreting pipe (4) runs through the entire length of the machine to issue at an outlet (10) in the downhole end of the pipe. A boring head (9) at this end is used in the rotary mode. Spirals (8) a few cm in height round the outlside of the drillpipe screw spoil to the surface. The vibrator (3) uses disbalancers (7) rotating round an axis (6) parallel to that of the drillpipe.