Mud Rotary Drilling is a common and dependable method of drilling through both consolidated & unconsolidated formations. This method utilizes drilling fluid (mud) as a circulating medium to; cool the drill bit, bring drill cuttings to the surface & maintain borehole integrity.

Advantages of Mud Rotary Drilling:
System efficiently removes drill cuttings keeping borehole open.
Ability to drill in excess of 1000'.
Large diameter boreholes.
The hydrostatic pressure in the borehole associated with the drilling mud will compensate formation pressures caused by water pressure. (i.e. heaving sands).
Formations are sealed by the "mud-cake" keeping fluids from migrating from various zones.

The proper mud program will stabilize most formations allowing for well installations. Drilling mud rotary seals off the formation as you drill preventing cross contamination between various zones.