the core receiver having a core forming cutting edge or element, e.g. punch type core barrels

Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors > the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe > the core receiver having a core forming cutting edge or element, e.g. punch type core barrels

Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors (core bits E21B10/02) > the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe > the core receiver having a core forming cutting edge or element, e.g. punch type core barrels