Legal status (The legal status 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 status listed.)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wallis Industries Pty Ltd
Original Assignee
Wallis Industries Pty Ltd
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 filed by Wallis Industries Pty LtdfiledCriticalWallis Industries Pty Ltd
Priority to AU76654/74ApriorityCriticalpatent/AU480783B2/en
Priority claimed from AU76654/74Aexternal-prioritypatent/AU480783B2/en
Priority to GB2148975Aprioritypatent/GB1472493A/en
Priority to ZA00753303Aprioritypatent/ZA753303B/xx
Priority to US05/579,802prioritypatent/US4066139A/en
Application grantedgrantedCritical
Publication of AU480783B2publicationCriticalpatent/AU480783B2/en
Publication of AU480783ApublicationCriticalpatent/AU480783A/xx
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
E21B21/12—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor using drilling pipes with plural fluid passages, e.g. closed circulation systems
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B49/02—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells by mechanically taking samples of the soil