Site Investigation Requirements for HDD Projects

Before a Abrasion Protective Coating  (ARO) is selected for a HDD project, the engineering firm in charge of the project conducts an investigation. The procedure involves generating site characterization information relative to the design, permitting, execution, and certification of HDD Pipeline Installations.

This information will allow the engineer and contractor to enhance / streamline design, control risk, improve the over all integrity and long-term performance of the facility.

This information will determine the selection of the HDD methodology, the investigation shall cover:

  • Definition of the obstacle to be crossed – not only as is, but also any possibility of changes over time.
  • Information of the condition that must be transited by the HDD process: Passive features as well as Active conditions.

Passive features:

  • Geological factors
  • Topographical and Hydrographical Data
  • Geotechnical aspects – Material classification (rock quality Designation RQD), strength properties, deformation properties, groundwater table behaviour.

Active conditions (Products)

  • Shape condition of the bored hole
  • Crossing geometry
  • Drilling conduct
  • Pipe diameter and construction
  • Sequencing for drilling
  • Subsurface voids
  • Site integrity
  • Drilling timing
  • Drilling mud

With the data compiled and analysed, the engineer can proceed to make recommendations on the process sequence and protection redundancies to reduce risk.

The single most important decision in relation to mechanical protection after the study is the type of abrasion protective coating and mechanical protection. Based on this information, the requirements for the ARO coating are determined, such as flexibility, impact, compression, gauging, abrasion, field and application restrictions among others. This information will be used to define the coating selection and installation sequence such as the total dry film thickness requirements, coating installation sequence, field joint coating solution, etc.

Among all these considerations, the selection of the mechanical protective coating is the most critical step in the design of the HDD process. The right coating will ensure a successful outcome As it was demonstrated in the recent  MGL project in India.

Seal For Life are pleased to have qualified technical support available to assist you in the best selection of your mechanical protection system. We offer POWERCRETE, a fantastic choice for HDD coatings and protective systems.

By, Mario Moreno P.Eng. NACE CIP Level 3

Product Manager