50-38 Operation D20x22 Series II Navigator HDD
GAUGES - MONITOR DURING PULLBACK
Monitor gauges during drilling operation to ensure a good pilot bore. Watching the
gauges will help establish a baseline for rotation and thrust/pullback pressures.
Ideally, the pullback pressure will remain low while the reamer mixes drilling fluid
with the soil to form a good slurry flow through the annular space.
Rotation Pressure (1)--If rotation pressure is spiking, you may be pulling back too
fast for the ground conditions. A rise in rotation pressure can also mean that the
reamer has encountered harder ground.
Thrust/Pullback Pressure (2)--A steady rise in pullback pressure could indicate a
loss of fluid flow through the annular space, causing the product to become stuck or a
frac-out to occur.
Drilling Fluid Pressure (3)--The drilling fluid pressure gauge is best used as an indicator that flow is
occurring. Pressure can vary based on flow rates and nozzle sizes used in the tooling. A maximum indication on
the drilling fluid pressure gauge could be an indicator that flow has become restricted. Drilling fluid pressure is
approximately 50% of hydraulic pressure shown on gauge.
DRILL ROD - REMOVE
Refer to “Drill Rods - Remove from Drill String,” page 30-41.
Rod Box - Changing
Refer to “Rod Box - Remove,” page 30-35.