CPC Subgroup
E21B 25/16 for obtaining oriented cores
Full Title
Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors (core bits E21B10/02) > for obtaining oriented cores
E21B 25/16 Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors (core bits E21B10/02) > for obtaining oriented cores