Horizontal Directional Drilling
Steerable trenchless construction method for installing underground utilities without excavating continuous trenches
Understanding HDD Technology
What is Horizontal Directional Drilling?
Horizontal Directional Drilling (HDD) is a steerable trenchless construction method that enables installation of underground utilities without excavating continuous trenches. HDD is a construction technique whereby a tunnel is drilled under a waterway or other designated area, and a pipeline or other utility is pulled through the drilled underground tunnel.
The underground tunnel follows an arc line from the entry point, down under the special crossing area, and then resurfaces on the opposite side. Operators use a surface-launched drilling rig to drill a horizontal hole beneath obstacles on the surface, creating a precisely controlled bore path that can navigate around existing utilities and geological features.
Installation of a pipeline by HDD is generally accomplished in three stages: directionally drilling a pilot hole, enlarging the pilot hole to a diameter suitable for the product pipeline, and pulling the product pipe through the enlarged hole.
Traditional Challenges
Traditional open-cut installation creates significant disruption:
HDD Advantages
Trenchless installation is faster and more efficient. You don't spend time on extensive surface restoration after laying the pipe.
When is HDD the Optimal Solution?
Obstacle Crossings
Environmental Protection
Infrastructure Challenges
The Three-Stage HDD Process
Installation of a pipeline by HDD is generally accomplished in three stages, each critical to the success of the project.
Pilot Hole Drilling
A pilot hole is horizontally drilled along a predetermined design path. An electronic transmitter behind the drill head sends signals to the surface for real-time tracking.
Diameter
140-311mm
Accuracy
0.01° pitch
Guidance
Gyroscopic
Tracking
Real-time
Drilling fluid pumped through drill pipe carries cuttings back to entrance pit
Pre-Reaming
The pilot hole is enlarged to a size sufficient to safely install the product lines. A reamer is pulled back and rotated while pumping drilling fluid.
Continuous circulation of drilling fluids maintains hole integrity
Pipe Pullback
The pipeline is prefabricated and connected to the reamer. A swivel allows the reamer to turn without the product turning during pullback.
Drilling fluid provides lubrication during the entire pullback process
Advanced HDD Service Capabilities
Power & Force
High-Performance Capabilities
Drilling System
Fluid Management & Rods
Installation Range
Bore Capabilities
Intelligent Control Systems
Manual Mode
Semi-Automatic Mode
Fully Automatic Mode
Fiber Optic Expansion
Water Infrastructure
Energy Sector
Environmental Projects
Technical Excellence
Soil Conditions & Solutions
Ideal Conditions:
Challenging Conditions:
Drilling Fluid Technology
Determining soil type allows us to mix the most suitable drilling fluid for the job, ensuring the highest productivity levels with environmentally safe Bentonite base.
Fluid Functions:
Bentonite creates a "cake layer" around the hole during pre-reaming for stability and fluid loss control. Polymers help break up clay soils.
Advanced Guidance & Tracking Systems
Our self-developed steering tool based on Gyro technology makes it possible to determine the exact position of the drill without need for magnetic fields or beacons.
Economic & Environmental Benefits
Direct Cost Savings
Reduced excavation costs, minimal restoration expenses, shorter project duration, lower labor requirements
Time Efficiency
Faster installation than open-cut, no extensive surface restoration, continuous operations capability
Environmental Impact
90% reduction in surface disturbance, zero dewatering, preserved vegetation, protected water resources
Long-Term Value
Extended pipeline life, reduced maintenance, future expansion capability, improved community relations
Safety & Environmental Stewardship
Safety Protocols
Sustainable Practices
HDD Projects
Explore our completed horizontal directional drilling installations
