Hole Cleaning/Bailing Velocity
For proper LP drill performance and longevity, the bailing velocity must be adequate to clean the hole. Inadequate hole bailing will result in poor drill performance, rapid wear of external components, and premature bit wear. Bailing velocity speeds for horizontal drilling should be a minimum of 10,000 ft/min.
Bailing velocity is defined as the velocity of the exhaust air in the annulus created between the borehold ID, and the drill pipe OD, at atmospheric pressure. Soaps or foams are recommended to assist with hole cleaning.
Torque Requirements
Rule of thumb 500 ft/lbs per inch of bit diameter
Hammers/Bits
(3) RF-35LP Hammers
(3) 4.25" LP Bits
Smallest recommended drill pipe
2.375" od x 1.000" ID
Air Requirements
General 200-300 CFM of air per hammer housed in canister @150-250 PSI (600-900 CFM total)
Compressor recommendation
(1) 915 CFM x 350 PSI
Hammer pressure around 210 PSI
Hammers/Bits
(3) RF-50LP Hammers
(3) 5.75" LP Bits
Smallest recommended drill pipe
2.625" od x 1.250" ID
Air Requirements
General 300-400 CFM of air per hammer housed in canister @150-250 PSI (900-1,200 CFM total)
Compressor recommendation
(2) 900 CFM x 350 PSI
Hammer pressure around 210 PSI
Bailing velocity around 9,460 ft/min
Hammers/Bits
(3) RF-50LP Hammers
(3) 5.75" LP Bits
Smallest recommended drill pipe
2.625" od x 1.250" ID
Air Requirements
General 300-400 CFM of air per hammer housed in canister @150-250 PSI (900-1,200 CFM total)
Compressor recommendation
(2) 900 CFM x 350 PSI
Hammer pressure around 265 PSI
Bailing velocity around 10,908 ft/min
Hammers/Bits
(3) RF-60LP Hammers
(3) 7.875" LP Bits
Smallest recommended drill pipe
3.50" od x 1.50" ID
Air Requirements
General 400-500 CFM of air per hammer housed in canister @150-250 PSI (1,200-1,500 CFM total)
Compressor recommendation
(2) 915 CFM x 350 PSI
Hammer pressure around 210 PSI
Bailing velocity around 10,075 ft/min
(2) 1150 CFM x 350 PSI
Hammer pressure around 265 PSI
Bailing velocity around 12,660 ft/min
Hammers/Bits
(3) RF-60LP Hammers
(3) 7.875" LP Bits
Smallest recommended drill pipe
3.50" od x 1.50" ID
Air Requirements
General 400-500 CFM of air per hammer housed in canister @150-250 PSI (1,200-1,500 CFM total)
Compressor recommendation
(2) 1350 CFM x 350 PSI
Hammer pressure will exceed recommendations and will require jet sub
Bailing velocity around 7,700 ft/min
(3) 1150 CFM x 350 PSI
Hammer pressure will exceed recommendations and will require jet sub
Bailing velocity around 9,850 ft/min
Hammers/Bits
(4) RF-60LP Hammers
(4) 7.875" LP Bits
Smallest recommended drill pipe
4.00" od x 2.25" ID
Air Requirements
General 400-500 CFM of air per hammer housed in canister @150-250 PSI (1,600-2,000 CFM total)
Compressor recommendation
(2) 1350 CFM x 350 PSI
Hammer pressure will be around 250 PSI
Bailing velocity around 8,175 ft/min
(3) 1150 CFM x 350 PSI
Hammer pressure will exceed recommendations and will require jet sub
Bailing velocity around 10,448 ft/min
Hammers/Bits
(5) RF-60LP Hammers
(5) 7.875" LP Bits
Smallest recommended drill pipe
4.50" od x 2.50" ID
Air Requirements
General 400-500 CFM of air per hammer housed in canister @150-250 PSI (2,000-2,500 CFM total)
Compressor recommendation
(3) 1150 CFM x 350 PSI
Hammer pressure will be around 240 PSI
Bailing velocity around 7,930 ft/min
(3) 1350 CFM x 350 PSI
Hammer pressure will exceed recommendations (around 285 PSI) and will require jet sub
Bailing velocity around 9,315 ft/min
(4) 1150 CFM x 350 PSI
Hammer pressure will exceed recommendations (around 310 PSI) and will require jet sub
Bailing velocity around 10,575 ft/min