We evaluate proposed HDD crossings to determine technical feasibility and identify project-specific risks prior to final design or construction. • Review and interpretation of geotechnical and geophysical data • Assessment by soil and rock classification • Evaluation of proposed bore length, depth, and diameter • Identification of risks related to hole stability, loss circulation, and inadvertent returns • Assessment of site constraints, access, and constructability • Recommendations for alternative trenchless or conventional methods when HDD is not technically viable • Knowing what can and cannot be achieved with HDD is paramount from the outset.

Our design service is built on years of practical, in-depth HDD expertise, paired with a strong foundation in engineering principles. We develop and review HDD profiles to ensure compliance with engineering limits, drilling equipment capabilities, and installation tolerance. Years of experience have also given us the expertise to recommend the appropriate tooling and steering system for your project. Examples • Large Diameter Designs • Complex Built-up Areas Designs • Multi-bore Site Design • Outfall / Shore Approaches • Gravity Sewers • Pipe string pull-back areas & site layout design

Hydro-fracture, also called frac-out or inadvertent returns, occurs in Horizontal Directional Drilling (HDD) when drilling-fluid pressure exceeds the soil or rock strength, causing the fluid to escape through cracks to the ground surface, riverbed, or nearby utilities. Hydrofracture analysis is performed to predict, prevent, and control such failures during HDD operations. • Analysing the geotechnical data to model the anticipated shear failure of the soil that causes hydrofracture in the borehole wall, • Calculating the anticipated annular pressures while drilling to ensure maximum precautions are taken at the design stage to minimise the chance of Frac-out/Inadvertent Mud returns • In certain ground conditions where hydrofracture risk is high, design changes and other mitigating procedures can be introduced. • Hydrofracture analysis is performed to predict, prevent, and control such failures during HDD operations.

Pullback pressure in HDD (Horizontal Directional Drilling) refers to the axial stress and contact pressure generated in the product pipe while it is being pulled back through the drilled bore. It is a critical design and construction parameter because excessive pullback force or pressure can cause pipe yielding, buckling, coating damage, or joint failure. By calculating the estimated pullback pressures, we can • Check that the product pipe can withstand the forces it is subjected to during the pullback is essential to a successful project. • Check the rig has sufficient pullback capacity to install the product pipe.

We perform detailed engineering calculations to evaluate installation loads and pipe integrity. • Calculating external hydrostatic and soil pressures. • Assessing external hydrostatic and soil pressure effects on the product pipe. • Evaluating soil interaction with the product pipe after installation, ensuring that external hydrostatic and soil pressure forces don’t damage the product pipe over time (e.g. implosion, ground arching).

Ensuring that the HDD works do not cause surface movement or damage to any assets such as roads and rail. Settlement calculations in HDD (Horizontal Directional Drilling) are performed to predict and control ground surface settlement that may occur above or near a drilled bore. Excessive settlement can damage roads, buildings, pipelines, utilities, and pavements, so it is a critical design and construction check.