Drilling Methods

Drill Force use a number of different drilling methods. 

These drilling methods are selected and used with New Zealand’s unique geological nature and the purpose of the well being considered.

During the drilling process a number of methods may be required to meet the client's sampling and completion requirements. Please find a list of alternative drilling methods;

Rotary Wash Drill

Open hole type drilling and sampling method using a fluid (water or oil based) flushing medium. With our onboard mud pumps and Drill Force owned "plug-in" auxilliary high volume pumps, tri-cone roller type bits, drag type bits and PDC bits we have the current capacity and equipment to rotary wash drill hole diameters in excess of 400mm for water well, exploration, production wells and instrumentation type wells.

Rotary Air Blast (RAB)

Open hole type drilling and sampling method using air as the  flushing medium. With our onboard compressors and Drill Force owned "plug-in" auxilliary high pressure compressors, tri-cone roller type bits, drag type bits and PDC bits we have the current capacity, (dependent on ground conditions) and equipment to provide this drilling method.

Down Hole Hammer (DTH)

Open hole type drilling and sampling method using an air driven down hole hammer and the exhausting air as the flushing medium. With our onboard compressors and Drill Force owned "plug-in" auxilliary high pressure compressors, DTH hammers and bit selection we have the capacity and equipment to drill from 4" to 12" holes.

Reverse Circulation (RC) Down Hole Hammer, Blade or Tri-cone Roller

Typically a mineral sampling method using air as a flushing medium, where a representative sample is drawn through a dual tube type drill pipe back to surface.

Continuous and Conventional Wire Line Coring

Preferred drilling method where an "undisturbed" sample is required for further testing and analyses. With this drilling method, SPT, push tube and formation permeability testing can be undertaken during the drilling process without the requirement to withdraw the drill rods from the well. Typical size core samples are NQ @45mm, HQ @61.1mm and PQ @83mm. These core samples are retrieved by using a selection of drilling bits and core catcher configurations to suit the geology as it is intersected and changes throughout the drilling of the well.

Auger

Augers can be used to provide bulk disturbed samples for environmental purposes and when using hollow stem augers, can be used as temporary casing whilst installing instrumentation. Augers are also used to "open hole" large diameters prior to setting conductor casing.

MarketRig 1, HD54MRig 2, YDX3LRig 3, T300MRig 5, YDX1800ARig 15, 1000Rig 24, DT250Rig 31, Cat CompRig 48, V100-NG
Water Well V good Poor V good Poor V good Good Poor V good
Geotechnical Poor V good V good V good Poor V good V good V good
Construction Good Good V good Good Good Good Good V good
Environmental Good V good V good V good Good V good V good V good
Seismic Poor Good V good Good V good V Good Good V good
Exploration V good V good V good V good Good V good V good V good
Coal V good V good V good V good Good V good Good V good
CBM Production V good Unsuitable Good Good Unsuitable Unsuitable Unsuitable Good
CBM Exploration V good Good Good Good Good Good Unsuitable Good
CBM Re-injection V good Good V good Good V good Good Unsuitable V good
CBM Pump/work-over V good Good V good V Good Good Good Unsuitable V good
UCG Production V good Unsuitable Good Good Good Unsuitable Unsuitable Good
Shallow Oil and Gas V good Unsuitable Unsuitable Unsuitable Unsuitable Unsuitable Unsuitable Good
Geothermal V good Good V good Good Good Good Good V good
Wash drill V good Good V good Good V good V Good Good V good
Core Good V good V good V good Poor V good V good V good