Special methods or apparatus for drilling

EFIXED CONSTRUCTIONS E21Mining E21BEARTH DRILLING

E21B7/00Special methods or apparatus for drilling

E21B7/001Drilling a non circular hole E21B7/002Drilling with diversely driven shafts extending into the borehole E21B7/003Drilling with mechanical conveying means E21B7/005with helical conveying means E21B7/006combined with a bucket-type container E21B7/007Drilling by use of explosives E21B7/008Drilling ice or a formation covered by ice E21B7/02Portable drilling rigs, truck-or skid-mounted, with their own drive E21B7/021With a rotary table E21B7/022Control of the drilling operation; Hydraulic or pneumatic means for activation or operation E21B7/023the mast being foldable or telescopically retractable E21B7/024having means for adapting to inclined terrain; having means for stabilizing the vehicle while drilling E21B7/025Rock drills E21B7/026having auxiliary platforms E21B7/027Drills for drilling shallow holes E21B7/028the drilling apparatus being detachable from the vehicle E21B7/04Directional drilling E21B7/043for underwater installations E21B7/046horizontal drilling E21B7/06Deflecting the direction of boreholes E21B7/061the tool shaft advancing relative to a guide E21B7/062the tool shaft rotating inside a non-rotating guide travelling with the shaft E21B7/064specially adapted drill bits therefor E21B7/065using oriented fluid jets E21B7/067with means for locking sections of a pipe or of a guide for a shaft in angular relation E21B7/068drilled by a down-hole drilling motor E21B7/10Correction of deflected boreholes E21B7/12Underwater drilling E21B7/122with submersible vertically movable guide E21B7/124with underwater tool drive prime mover E21B7/1245using explosive means E21B7/128from floating support with independent underwater anchored guide base E21B7/132from underwater buoyant support E21B7/136from non-buoyant support E21B7/14Drilling by use of heat E21B7/143underwater E21B7/146Thermal lances E21B7/15of electrically generated heat E21B7/16Applying separate balls or pellets by the pressure of the drill, so-called shot-drilling E21B7/18Drilling by liquid or gas jets, with or without entrained pellets E21B7/185underwater E21B7/20Driving or forcing casings or pipes into boreholes E21B7/201with helical conveying means E21B7/203using down-hole drives E21B7/205without earth removal E21B7/206using down-hole drives E21B7/208using down-hole drives E21B7/24Drilling using vibrating or oscillating means E21B7/26Drilling without earth removal E21B7/265Combined with earth removal E21B7/28Enlarging drilled holes E21B7/30without earth removal