Spiral Double Tube Core Bit

The Spiral Double Tube Core Bit is specially designed for geological exploration projects where core quality and recovery rate are critical. By combining a spiral cutting structure with a double-tube system, this bit effectively protects the core sample from disturbance while maintaining stable penetration in complex formations. It is widely used in mineral exploration, engineering investigation, and broken or mixed ground drilling.

The Spiral Double Tube Core Bit is engineered to improve core recovery in fractured, loose, or mixed formations. Unlike single-tube core bits, the double-tube structure allows the inner tube to remain relatively stationary while the outer tube rotates and cuts the formation.

This design minimizes disturbance to the core sample, reduces washing effects, and significantly improves recovery rate-especially in broken strata, gravel layers, and weathered rock.

It is widely used in mineral exploration, geotechnical investigation, hydropower projects, and engineering geology where core integrity directly affects decision-making.

Double Tube Design
Inner tube protects the core from flushing erosion
Outer tube handles cutting and torque transmission
Greatly improves core recovery ratio

 

Spiral Cutting Structure
Enhances cuttings discharge efficiency
Reduces torque fluctuation during drilling
Maintains stable penetration speed

 

Optimized Waterway System
Prevents clogging in broken formations
Improves cooling and debris removal
Reduces drilling interruption risk

 

Reinforced Bit Body
High-strength alloy steel body
Excellent resistance to impact and abrasion
Suitable for long continuous drilling cycles

Suitable formations include:
Broken rock zones
Gravel and pebble layers
Weathered rock
Mixed soil–rock formations
Karst and fractured limestone
 

Typical applications:
Geological exploration drilling
Mineral resource investigation
Hydropower and foundation projects
Engineering geological surveys
Core sampling in unstable formations

Each Spiral Double Tube Core Bit is produced under strict quality control standards:
High-grade alloy steel forging
Precision CNC machining
Optimized spiral blade geometry
Heat treatment for strength and wear resistance
Strict concentricity and balance inspection
Final quality inspection before delivery
This ensures every bit performs reliably under demanding drilling conditions.

Project Background – Copper Exploration Project, Northern Chile
The project is located in northern Chile, a well-known copper mining region characterized by highly fractured formations, mixed gravel layers, and weathered volcanic rock.
During the early drilling stage, the contractor used conventional single-tube core bits. However, several issues quickly appeared:
Severe core breakage and loss
Low core recovery rate
Frequent blockage caused by loose gravel
Unstable drilling progress and repeated reaming
These problems significantly affected geological logging accuracy and slowed down the exploration schedule.

Solution Provided
After technical evaluation, the drilling team switched to our Spiral Double Tube Core Bit, specifically designed for unstable and broken formations.
Key improvements after replacement:
🔹 Core recovery increased by 35–40%
🔹 Much cleaner and more intact core samples
🔹 Reduced hole collapse and flushing blockage
🔹 More stable drilling parameters
🔹 Overall drilling efficiency improved by around 20%

Recommended for broken, weathered, or mixed formations
Maintain moderate rotation speed to avoid excessive vibration
Ensure stable water or mud circulation for proper cuttings removal
Regularly inspect inner tube wear condition
Avoid aggressive feed pressure in fractured zones
Proper operation significantly extends bit life and improves core quality.