The inner-tube group is composed of:
Head Assembly
Inner Tube
Core Lifter Case
Core Lifter
Stop Ring
 

The inner-tube group collects the core sample during the drilling process and is independent of the outer-tube group.

The outer-tube group is composed of the remainder of the core barrel components:
 

Locking Coupling
Adapter Coupling
Outer Tube
 

The outer-tube group always remains at the bottom of the hole and houses the inner-tube group during the drilling process.

The core barrel assembly is composed of the inner-tube group and outer-tube group.
 

1 head assembly
2 inner tube
3 stop ring
4 core lifter
5 core lifter case
6 locking coulping
7 adaptor coupling
8 landing ring
9 outer tube
10 stabilizer
 

Wireline drilling is the special method of removing the core. When the driller wants to remove core from a conventional core drill, the entire core barrel has to be removed from the hole. This is time-consuming, as each rod has to be removed one at a time. With wireline drilling, a barrel of core can be removed from the bottom of the hole without removing the rod string. When the driller wants to remove the core, an overshot is lowered on the end of a wireline. The overshot attaches to the back of the core barrel inner tube and the wireline is pulled back and the inner tube disengages itself from the barrel.

Technical Data: