HQUD Horizontal Wireline Overshot | QUD Series Fishing Tool for Horizontal Tunnel & Inclined Hole Coring

HQUD Horizontal Wireline Overshot is a professional wireline coring fishing tool specially designed for horizontal drift drilling, tunnel advanced exploration and upward inclined boreholes. It matches HQU series horizontal wireline coring drill rods and inner tube assemblies.
Optimized for horizontal working conditions such as no gravity feeding, high borehole friction, water gushing and deep-hole drilling, this overshot is hydraulically driven into position by drilling mud. It can retrieve the core barrel efficiently without tripping the whole drill string, greatly improving horizontal drilling efficiency for large and medium-sized tunnels and deep underground projects.
Equipped with torsion-release lifting ring, built-in jarring mechanism and self-locking anti-drop fishing head, the HQUD overshot ensures smooth running, firm grabbing and stronger load-bearing capacity for deep hole conditions. The main body is made of high-strength 40Cr steel with heat treatment, and the fishing dogs are alloy quenched for high wear resistance. Stable, durable and easy to maintain, it fully complies with DCDMA standards and is widely interchangeable with mainstream drilling tools.
Certifications: ISO, RoHS, MSDS

1. Hydraulic feeding design dedicated for horizontal boreholes
Customized for medium and large HQ horizontal and inclined holes. Instead of relying on gravity drop used in vertical-hole overshots, it is pushed downhole by drilling mud pressure, solving high-resistance feeding difficulties in long-distance deep horizontal holes, ideal for large and medium tunnel and deep underground horizontal coring.
2. Self-locking anti-drop structure for high safety
Equipped with 3-piece high-strength alloy fishing dogs plus rotary locking sleeve for double self-locking protection. It locks automatically once engaged with the inner tube spear head. No slipping under deep-hole vibration, high-pressure mud erosion and negative pressure pulling, completely avoiding inner tube falling and core loss accidents.
3. Built-in buffer jarring assembly for releasing stuck tools
Reinforced jarring cylinder and rod effectively solve tube sticking caused by heavy rock powder accumulation and mud adhesion in deep horizontal holes. Quick jarring force releases jams and reduces deep-hole failure and rework rate.
4. Tapered centralizing guide for smooth running
Widened front taper guide perfectly matches HQU inner hole passage, ensuring no wall scraping, no deviation and no blockage during long-distance feeding, delivering stable reaching to deep hole bottom.
5. Torsion-releasing swivel lifting ring
Heavy-duty thrust bearing and rotary joint eliminate wire rope torsion during deep-hole lifting, preventing rope distortion and fatigue fracture and improving deep drilling safety.
6. Standardized size & easy disassembly
Manufactured in accordance with DCDMA standards, fully compatible with HQU medium-large bore horizontal wireline drill rods and inner tube assemblies. Modular structure enables fast on-site replacement of wearing parts for easy maintenance.