Overshots is a necessary device in wireline drilling. It is dropped on a cable and directly couples onto and lifts up the inner tube assembly, eliminating the need to couple and uncouple the rod string each time the core is retrieved.
Overshot Size | BQ | NQ | HQ | PQ |
Q Series Wireline Double Tube Core Barrels | |||
Size | Hole(mm) | Core(mm) | Head Thread |
BQ | 59.3 | 36.2 | BQ rod box |
NQ | 75.2 | 47.6 | NQ rod box |
HQ | 95.6 | 63.5 | HQ rod box |
PQ | 122 | 85 | PQ rod box |
Q Series Wireline Triple Tube Core Barrels | |||
Size | Hole(mm) | Core(mm) | Head Thread |
NQ3 | 75.2 | 45 | NQ rod box |
HQ3 | 95.6 | 61 | HQ rod box |
PQ3 | 122 | 83 | PQ rod box |