1. General Description
- Model: GRAN100
- Manufacturer: GRANFI LTD
- Machine Type: Portable borehole drilling rig
- Maximum Drilling Depth: 100 meters
- Designed for light to medium-duty borehole drilling
2. Drilling Capability
- Drilling Methods:
- Air drilling (DTH – Down-The-Hole hammer)
- Mud rotary drilling
- Drilling Diameters:
- 6 inches – Air drilling (standard bore)
- 7 to 8 inches – Mud drilling (via reaming)
- Suitable for:
- Water wells
- Rural and community boreholes
- Farm irrigation systems
3. Structural Design
- Mast Type: Vertical steel mast (guide tower configuration)
- Frame: Heavy-duty mild steel fabrication
- Base: Reinforced chassis (skid or trolley adaptable)
- Mounting Options:
- Trolley-mounted
- Vehicle-mounted (e.g., Land Cruiser, pickup)
4. Feed & Hoisting System
- Feed Mechanism: Hydraulic push/pull system
- Main Cylinder: Vertical hydraulic cylinder for lifting and feed
- Auxiliary Cylinder: Inclined stabilizer/tilt cylinder
- Functions:
- Raising and lowering drill rods
- Applying controlled weight-on-bit
- Stabilizing mast during operation
5. Rotation System
- Rotary Head: Hydraulic or mechanically driven
- Provides torque for:
- Rotary mud drilling
- Driving DTH hammer (air drilling support)
6. Hydraulic System
- Type: Multi-cylinder hydraulic system
- Controls: Manual hydraulic valve bank
- Functions:
- Mast lifting
- Feed control
- Structural stabilization
7. Power System
- Typically powered by:
- Diesel engine (field standard) or
- External hydraulic power pack
- Supports:
- Rotation system
- Hydraulic actuation
8. Mobility & Deployment
- Portable and compact design
- Can be:
- Mounted on a trolley for short-distance movement
- Installed on a vehicle (Land Cruiser/pickup) for field operations
- Ideal for:
- Remote locations
- Off-road drilling environments
9. Supporting Equipment (Required)
To operate effectively, the rig works with:
- Air compressor (for 6” air drilling)
- Mud pump system (for 7–8” mud drilling)
- Drill rods and bits (DTH hammer or tricone/drag bits)
10. Key Features
- Dual drilling capability (air + mud)
- Variable bore diameter through reaming
- Compact, mobile, and field-ready
- Low setup and transport cost
- Adaptable to mixed geological formations
11. Advantages
- Excellent for Kenyan geology (mixed soil + hard rock)
- Cost-effective for small drilling contractors
- Easy to mobilize compared to truck-mounted rigs
- Flexible drilling diameter depending on method used
🧠 Engineering Insight
The drilling diameter configuration is particularly strategic:
- 6” (Air drilling):
- Faster penetration in hard rock
- Lower energy losses
- Ideal for deep sections
- 7–8” (Mud drilling via reaming):
- Used for surface casing zones
- Improves borehole stability
- Allows installation of larger casing
👉 This combination makes the GRAN100 a highly practical hybrid rig, capable of handling:
- Overburden (mud drilling + reaming)
- Hard rock (air drilling with DTH)
⚠️ Operational Limits
- Maximum efficient depth: ~100 m
- Not suited for:
- Large-diameter (>8”) boreholes
- Heavy industrial or deep (>150 m) drilling
Why GRAN100?
The GRAN100 is a portable, vehicle-mountable borehole drilling rig capable of drilling up to 100 meters, with 6-inch air drilling and 7–8 inch mud drilling (reamed), making it ideal for small to mid-scale water projects in varied ground conditions.
How Expensive is it?
Bare rig without rods and compressor will cost between Kshs.800,000 to Kshs.1,500,000
💡 Why cheaper?
- Locally fabricated (GRANFI)
- No import duty/shipping
- Simpler hydraulic system
To actually operate the rig (air + mud), you need:
A. Air Drilling System (for 6” holes)
- Air compressor (18–25 bar):
👉 KES 1.2M – 2.5M
B. Mud Drilling System (for 7–8” reaming)
- Mud pump: KES 150K – 400K
- Mud tank + hoses: KES 50K – 150K
C. Drill String & Tools
- Drill rods: KES 150K – 400K
- DTH hammer + bits: KES 200K – 500K
- Reamer bits (7–8”): KES 80K – 200K
D. Support Equipment
- Winch / hoist accessories: KES 50K – 150K
- Tools, spares, fittings: KES 50K – 100K
Get in touch for more clarification or help