The first well washing circulation can't stop, should pay attention to the washing liquid from the wellhead outflow. The second is to pump unexpected problems led to stop, immediately raising a drill bit, in order to avoid being sand. Third bit nozzle is smaller, the way should be to prevent the nozzle is blocked.

a point, in addition to rolling out there, drilling teeth do rolling cutting effect, the bottom gradually being broken, so successfully drilled through strata.

Method of operation

1 measurements of good size, matching the corresponding joint.

2 well check each bit roller flexibility, loose or not, connection of drilling tools.

3 to the bottom, the rotating disk, to be smooth, then slowly down, all the sand flushing as well.

Gradually add pressure to 4 bit, the intensity should not be too large, otherwise the bit may lead to deformation or wheel fall off slowly.

5 drilling speed must be just perfect, drilling cement fifty to seventy drill more appropriate.