Pilot hole drilling
A small diameter pilot hole is drilled by directional control to a predetermined path from rig to pipe side.
Either a jet bit or a rock bit and mud-motor is used as a drilling tool in soft or hard ground. Surveying is achieved with an electronic instrument situated immediately behind the drilling tool.
Steering ability is provided by a slight bend in the pilot string between drilling tool and instrument, which is orientated while pushing the string forward.