Are cycle rig in drilling process in the according to geological situation control footage speed: by hard formation drill to soft formation of when, can appropriate of speed up drilling speed; Dang soft formation into hard formation of when, to deceleration slow into; in easy shrink diameter of formation among, should appropriate increased sweep hole times, prevent shrink diameter; for hard plastic layer used fast speed drilling, to improve drilling efficiency; sand layer is used slow speed slow drilling and appropriate increased mud share and stick degrees; as in actual construction process in the appeared pebble layer, Take the following measures: for the small grain size pebble layer bucket drill slowly into size large conical spiral drilling gravel layer replace bucket drill after cleaning, and so on, until through the gravel.

Above is on the use of normal circulation drilling methods, hope you can use it.