High adaptability to wear and tear resistance wireline core barrel assembly
The inner-tube group is composed of:
• Head assembly
• Inner-tube
• Core lifter case
• Core lifter
• Stop ring
HEAD ASSEMBLY
The head assembly provides latching and pivoting spearpoint mechanisms to allow insertion and retrieval of the inner-tube assembly, a bearing assembly to allow the inner-tube to remain stationary and avoid sample damage while drilling, fluid pressure operating indications and fluid control valves.
All head assemblies incorporate a shut off valve assembly which provides a fluid pressure
signal to the drill operator when the valve members are compressed, indicating a full or blocked inner-tube
INNER-TUBE
The inner-tube captures the core sample as drilling progresses. Multiple inner-tubes can be assembled with couplers or extensions to accept longer core samples.
CORE LIFTER CASE
The core lifter case mates to the inner-tube and houses the core lifter in a tapered socket which controls movement of the core lifter. As the drill string is lifted during a core breaking operation, the core lifter case bottoms out on the inside of the drill bit transferring the pullback load from the drill string to the core lifter until the core sample breaks.
CORE LIFTER
The core lifter is a hardened steel, split collar with a tapered body that mates to a tapered
socket in the core lifter case. In a core breaking operation, the drill string is lifted off bottom and the core sample begins to slide out of the inner-tube. Grip features on the inner surface of the core lifter catch the moving core sample and pull the core lifter towards the smaller end of the tapered socket in the core lifter case. The core lifter is constricted against the core sample and retains it after it has broken, allowing retrieval to surface.
STOP RING
The Stop Ring is a hardened steel snap ring designed to seat into a mating groove, and retain the core lifter in the core lifter case.