Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filedfiledCritical
Priority to NL6902809ApriorityCriticalpatent/NL6902809A/xx
Priority to BE732629Dprioritypatent/BE732629A/fr
Publication of NL6902809ApublicationCriticalpatent/NL6902809A/xx
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B7/00—Special methods or apparatus for drilling
E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
E21B7/201—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes with helical conveying means
E21B7/203—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes with helical conveying means using down-hole drives
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
E21D9/005—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries by forcing prefabricated elements through the ground, e.g. by pushing lining from an access pit