Foremost - Model DR-12 -Dual Rotary Well Drills
The DR-12 is a light, yet powerful PTO rig popular among domestic water well contractors drilling in moderate to severe overburden. It will handle casing up to 12″ (305 mm) in diameter, and has been field tested to depths beyond 550 ft (168 m) for a typical 6″ (152 mm) cased well. The DR-12 is available with an optional pipe tub, single pipe loader arm and telescopic casing jib. The configuration accommodates diverse site conditions.edddd
Since acquiring the Dual Rotary technology from Barber Industries in 1993, Foremost has continually updated, refined and expanded the DR line with the goal of enhancing its functionality and extending its range of applications. Today, Foremost offers several DR models, each packed with features that deliver heightened safety, productivity, and profitability across a variety of drilling activities.
The optional cyclone sample collecting system slows discharge velocity to allow accurate and continuous sampling of the formation.
All drill cuttings rise to the surface between the drill pipe and casing, and exit through the discharge swivel attached to the top of the casing. The discharge swivel directs cuttings to a safe dumping point or to an optional cyclone collection system.
A carbide-studded casing shoe is welded to the casing bottom. The shoe I.D. is flush with the casing I.D. so that there is no reduction in the bore hole diameter when switching to open-hole drilling.
Rotation and feed forces are effectively transmitted from the lower drive to the casing via a set of three carbide inserts. Casing jaws are available for all common casing sizes and can be changed out quickly in the field.
The independent hydraulic top drive tilts for convenient loading of drill pipe and casing with the operator standing at ground level.
The lower rotary drive is also used as a powerful breakout and spinner for drill pipe, hammers, bits, and thread casing.
Foremost Dual Rotary drills feature a unique lower rotary drive that is used to advance steel casing through unconsolidated overburden, such as sand, gravel, glacial till, and boulders. Pullback, pulldown, and rotational forces are effectively transmitted to the casing via high-strength steel jaws with carbide inserts.
An independent rotary top-drive simultaneously handles a drill string equipped with a down-the-hole hammer, drag bit, or roller cone bit. Cuttings are typically evacuated with air, but Foremost DR-drills can also be configured with pumps for mud or flooded reverse circulation drilling.
The top and lower drives feed independently, meaning that the bit position can vary relative to the bottom of the casing. Once the desired casing depth has been achieved, the DR continues drilling open-hole like a conventional top-drive drill. With a Foremost DR-drill, there is no need to trip out or change tools when transitioning to open-hole drilling.