Description
8 1/2″ (215.9mm) Four Cone Bit — Model 8 1/2LS637GDY-60
Advanced Four-Cone Drill Bit with Diamond Composite Inserts for High-Compressive & Highly Abrasive Formations
Size: 8 1/2 in / 215.9 mm
Core Diameter: Φ60mm
Bearing: Sliding Bearing
Connection: 5 1/2 IF
Key Performance Advantages for Field Engineers & Rig Managers:
- Four-Cone Enhanced Stability: Designed with four balanced cones to distribute downhole weight and torque evenly, drastically reducing dynamic vibration in abrasive strata.
- Diamond Composite Teeth Technology: Integrated with 20 premium diamond composite teeth alongside 164 cutting elements across 21 rows, offering extreme resistance to impact and severe abrasive wear.
- Advanced Compound Seal & Sliding Bearing: Built with a high-durability sliding bearing system and compound seal to prevent fluid ingress and thermal breakdown during heavy-duty drilling operations.
Product Overview & Technical Description
The 8 1/2LS637GDY-60 is an engineered 8 1/2″ (215.9mm) Four Cone Drill Bit built to tackle the most demanding geological formations featuring high compressive strength, medium hardness, and extreme abrasiveness.
Utilizing a four-cone geometry with a Φ60mm core diameter, this bit enhances cutting coverage across the bottom of the hole through 21 tooth rows containing 164 primary cutting teeth, 50 outer row teeth, 74 back cone teeth, and 104 palm back teeth. Enhanced by 20 strategic Diamond Composite Teeth, the 8 1/2LS637GDY-60 withstands high abrasive friction while preserving cutter geometry for maximum drilling efficiency and footage per run.
Technical Specifications — Model 8 1/2LS637GDY-60
| Parameter | Specification Value | Engineering Context / Notes |
|---|---|---|
| Diameter (Inches) | 8 1/2″ | Standard Hole Diameter |
| Diameter (Metric) | 215.9 mm | Metric Size Equivalent |
| Number of Cones | 4 | Four-cone cutting structure for enhanced bottom-hole stability |
| Core Diameter | Φ60mm | Optimized core clearance dimension |
| Connection Thread | 5 1/2 IF | Standard Internal Flush API Thread Pin |
| Bearing System | Sliding Bearing | Heavy-duty friction bearing engineered for extreme vertical load handling |
| Bearing Sealing System | Compound Seal | Multi-layer sealing mechanism preventing abrasive drilling fluid invasion |
| Number of Tooth Rows | 21 rows | High-density intermeshing cutter pattern |
| Cutting Teeth | 164 | Total primary cutting teeth elements across four cones |
| Outer Row Teeth | 50 | Dedicated gage wall cutter protection |
| Back Cone Teeth | 74 | Rear cone protection preventing bit reaming wear |
| Palm Back Teeth | 104 | Enhanced shirt-tail/palm protection against hole-wall erosion |
| Diamond Composite Teeth | 20 | PDC/PCD reinforced compacts for extreme abrasion resistance |
| Drill Pressure (WOB) | 60 – 180 KN | Recommended operational weight on bit loading range |
| Rotation Speed (RPM) | 40 – 180 RPM | Recommended operational speed envelope |
| Make-up Torque | 16.3 – 21.7 KN.M | Recommended thread connection makeup torque |
| Adaptation Formation | High compressive strength, medium hard and highly abrasive formations | Hard sandstones, quartziferous rock, limestone, and hard shales |
Field Pain Points Solved by 8 1/2LS637GDY-60
1. Pain Point: Severe Abrasive Wear in High Compressive Strata
Solution: Reinforced with 20 Diamond Composite Teeth and 164 durable cutting teeth, significantly extending cutting edge sharpness in highly abrasive hard rock.
2. Pain Point: Shirt-tail and Palm Back Erosion Leading to Cone Loss
Solution: Packed with 104 palm back teeth and 74 back cone teeth to shield bit legs against severe reverse reaming wear and wall fluid erosion.
3. Pain Point: Bearing Failures Under High Weight-on-Bit (WOB) Loads
Solution: Employs a robust Sliding Bearing system paired with a Compound Seal to handle high drill pressures up to 180 KN without seal failure.
4. Pain Point: Dynamic Vibration & Gage Collapse in Hard Rock
Solution: Four-cone geometry delivers smoother rotation and weight distribution, combined with 50 outer row teeth to hold precise 215.9mm hole diameter.
Recommended Operating Parameters & Guidelines
To ensure optimal penetration rate and bit lifespan for the 8 1/2LS637GDY-60, adhere to the following field guidelines:
- Weight on Bit (WOB): Operate between 60 KN and 180 KN. Increase weight gradually when transitioning into harder rock layers.
- Rotary Speed (RPM): Maintain speeds within 40 to 180 RPM according to formation hardness and motor torque parameters.
- Makeup Torque: Ensure precise thread torque between 16.3 KN.M and 21.7 KN.M using approved thread lubricant for 5 1/2 IF connections.
Frequently Asked Questions (FAQ)
