Overshots are an integral part of the Q Wireline system. Once the inner-tube is full of core, the overshot is lowered (or pumped-in for an inclined-hole) to the bottom of the hole. The Overshot is dropped or pushed into the drill string to bring back the inner tube assembly by means of wireline cable hoist. Its heavy-duty lifting dogs grab a secure hold at the top of the inner-tube assembly.
Overshot Assembly Specifications
BO (BQ) Overshot Assembly
B0-U Overshot Assembly
NO (NQ) Overshot Assembly
NO-U (NQ) Overshot Assembly
HO (HQ) Overshot Assembly
HO-U Overshot Assembly
PO (PQ) Overshot Assembly
PO-U (PQ-U) Overshot Assembly
Frequently Asked Questions
What is the primary function of an Overshot in wireline drilling?
The Overshot is a retrieval tool used to pull the inner-tube assembly containing the core sample out of the drill string without removing the drill rods.
How is the Overshot deployed into the borehole?
It can be lowered by gravity in vertical holes or "pumped-in" using water pressure for inclined or horizontal drilling applications.
What ensures the safety of the inner-tube during lifting?
The assembly features heavy-duty lifting dogs that automatically lock onto the spearhead of the inner-tube, providing a secure mechanical grip.
Are these Overshots compatible with standard Q series systems?
Yes, our Overshot assemblies are designed to be fully compatible with B, N, H, and P wireline systems, including "U" series variants.
Can the Overshot be used in deep hole drilling?
Absolutely. It is specifically designed for wireline cable hoist operations, making it efficient for retrieving core samples at significant depths.
What materials are used for the lifting dogs?
The lifting dogs are manufactured from high-strength, heat-treated alloy steel to ensure durability and prevent failure under heavy loads.
KAT DRILLING
