Mud rotary drilling is an open hole, fluid based recirculatory method of drilling.  The bore hole is advanced in rock and/or sediments by rapid rotation of a drill bit mounted at the end of drill rods.  NSF approved drilling fluid circulates in the bore-hole as it pumps down through the rod string, where it picks up drill cuttings and carries them to the surface.  The drilling fluid also lubricates the drill bit and provides hydrostatic pressure in the borehole to keep the hole open and stable for sampling and installations. Mud rotary drilling is used in bedrock, dense sand or tight gravel formations where hollow stem augers would be ineffective.

Holocene operates a variety of large and small truck mounted and track mounted auger rigs to meet both on road and off-road site conditions.  Holocene operates Diedrich D-70, D-50 track rigs, D-90 and 120 truck mounted rigs, CME 850 track rig, Mobile B-58 truck rigs that perform auger, mud rotary and rock coring. Drilling mud is circulated with deck mounted mud pumps.

Applications:  Best used in highly saturated silts, muds and in unconsolidated sediments where soil sampling is necessary. Mud rotary is effective up to about 1000’.  Not effective in consolidated rock, cobbles or gravels where mud circulation is difficult.

Rig Type	Length	Width	Height*	Weight (lbs)
D-70 Track Rig (3)	16′ 6″	8′	Tower up: 26′	25,000 No tooling
D-50 Track Rig (2)	14′ 6″	8′	Tower up: 25′ Short Tower 14′	22,500 No tooling
CME 850 Track Rig	18′ 6″	8′	Tower up: 29′	28,000 No tooling
D-90 Truck Rig	30′	8′	Tower up: 30′	35,000 No tooling
D-120 Truck Rig	30′	8′	Tower up: 30′	35,000 No tooling
B-58 Truck Rig	30′	8	Tower up: 30′	38,000 No tooling

* specifications are nominal and depths will vary depending on sub-surface conditions