Beretta T152
The Beretta T152 is the top of the line for installing geothermal wells. With the right operator this machine can drill one hole per day up to 900 feet in depth. This allows for the best geothermal conductivity of any loop field construction. It is also possible to drill this amount of footage in separate bore holes.
Counter rotating drill heads are the secret to this rigs capacity. The lower rotary provides 22,000 ft/lbs of torque turning the casing with a left hand rotation. The upper head provides up to 7,000 ft/lbs of torque to the inner rods with a right hand rotation. With this counter-rotating effect the drill cuttings move faster up the hole and the hole is drilled much straighter. There is a hydraulic cylinder between the two rotary heads allowing the inner bit to be pushed in front of the casings or to be pulled inside the casing for different drilling conditions. The double head can also be fitted with a diverter to move the cuttings away from the drilling and into a containment vessel. This allows the drill to operate in very confined spaces with little or no dust.
With the deep holes that can be drilled using the T152 a large air compressor is necessary to facilitate drilling. A 1000 CFM with 350-400 PSI is recommended for this type of drilling. This will power a 4-inch down hole hammer with a 5-inch bit very well to this depth.
A powerful mast with 36,000 lbs. of pullback keeps your string from getting stuck in the ground. Along with pumps, steel tracks and a compact design the T152 is the best available drill rig for installing geothermal boreholes.
