The Dual Rotary method has been proven repeatedly where unconsolidated formations (sand, gravel, cobbles, and boulders) make it difficult to drill a cased hole using conventional drilling techniques. The versatility of this unique drilling rig makes it one of the most efficient and cost effective methods for
drilling holes in difficult formations.

Derex 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 Derex 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 Derex DR drill, there is no need to trip out or change
tools when transitioning to open-hole drilling.

• Open-Hole Versatility – The DR can be configured for a variety of drilling methods including mud, reverse circulation, and flooded reverse circulation.
• Straight Holes – The rotation of the casing by the lower drive results in a very straight hole making it ideal for shaft holes and foundation piles. This also minimizes stress on casing and casing welds, and eases the task of installing screens and pumps in water well applications.
• Casing Extraction – The lower drive is equally effective at pulling back casing; thereby simplifying the process of exposing a well screen or abandoning a well.
• Utilizes Conventional Tools – The drill string can be equipped with down-the-hole hammer, roller cone, or drag bit.
• Control of Discharge – Cuttings are diverted through the discharge swivel and can be directed to a safe and convenient dumping or monitoring point.
• Ease of Maintenance – Derex DR rigs feature a directly connected hydraulic feed system which means no chains, sheaves, or sprockets to maintain. This type of feed system generates zero load on the mast crown, permitting a simple and lightweight mast design that does not sacrifice pullback capability.
• Reduced Operational Risk – The DR’s flexibility allows you to expand into new applications and gives you confidence to go into areas previously considered off-limits. You will know you have the right equipment to get the hole down the first time!
• Speed – There is arguably no DR drill on the market today that is as fast tripping and drilling as a Derex DR.
• Technical Support – Derex’s DR rigs are backed by the expertise and support of our product management team, field technicians, and one of the largest research and development teams in the industry.

Stroke 13’
Top Drive Speed 140’/min
Pullback 40,000lbs
Pulldown 20,000lbs
Torque (stall) 42,000 inch/lbs
TD Rotation Speed 0-140 RPM
Lower Drive Torque 180,000 inch/lbs
LD Rotation Speed 0-24 rpm
Casing Diameter 6”, 5” & 4” (with 8” & 10” option)

COMPRESSOR
Air Flow 665 CFM
Pressure 250 PSI

DIMENSIONS
Length 24’
Height <12’
Width 8’6”
Weight 34,000 lbs (loaded with drill pipe and all tooling)

WINCH
2500lbs

WATER & FOAM INJECTION
Capacity 8 gpm @ 600 psi