• Higher productivity as large diameter bores drilled in single pass
  • Much quicker bore hole completion as multiple pass reaming not required
  • Lower costs as much less energy used with LDFR:
  • 2 x compressors for Casing While Drilling phase < 1 shift
  • Single compressor used in LDFR phase to drill 17.5” hole


Large Diameter Flooded Reverse is a unique drilling method that delivers lower risk and higher yielding bores.
  • Geological Data is accurate and instantaneous
  • Samples are returned to surface immediately in the order they were drilled through RC system:
  • No lag time when compared with conventional Mud Rotary
  • Higher yielding bores:
  • Less aquifer clogging from drill cuttings as all cuttings are returned to surface through RC system
  • Only clean mud under gravity comes in contact with borehole/aquifer vs dirty mud and much higher UHV’s when drilling conventional Mud Rotary
  • Minimal aquifer clean up time and reduced air lifting


  • Very straight holes due to BHA configuration and collar weight
  • Less problematic boreholes:
  • Lost circulation zones are not an issue, fluid allowed to stabilize at natural SWL
  • Improved borehole stability as no turbulence above bit/stabilizers/collars which results in zero borehole wall degradation/erosion
  • Wider range of options to suit ground conditions:
  • LDFR with 10″, 20″ and 24″ Casing While Drilling (CWD) BHA assemblies
  • LDRC with 15” hammer and 18” bit