Horizontal directional drilling – then to the future

Horizontal directional digging machines like the Gallagher 660e are vital for trenchless pipeline installation

Stephen Loneragan of HDD Engineering has lived and breathed Horizontal Directional Drilling (HDD) design and engineering in Australia and overseas since the early 1990s. His forthright perspective on the HDD industry tells it how it was and is now. He has been collaborating with Maxibor Australia for many years, Loneragan took Inside Water through what can be done to enable HDD to add more value to the installation of pipelines across the Australian infrastructure sector.

Horizontal directional drilling – then

Back in the good old days, before hi-vis was a “thing”, HDD was equal parts black magic and art with the occasional dash of engineering thrown in for flavour. That was because we didn’t know any better. It was, at the time, a new and emerging pipeline installation technology. Drilling a 200 m bore, pulling in a six-inch pipeline, and getting the exit point within 5 m or 10 m was a huge success and worthy of a decent “pull back party” for the crew. Most of the time, a client wanted (or hoped for) both ends of the pipe to be on both sides of the river. 

As the HDD industry here in Australia grew and more experience was gained, the lengths and diameters of the crossings also increased. The dash of engineering became more of a required key ingredient. 

It was still an emerging technology and lacked the project precedent from which to draw references and learnings. 

Australia led the world in HDD development from the late 90s to around 2010. 

The east coast of Australia was particularly isolated from much of the Australian and the US oil fields, where much of the HDD technology was being derived and modified. As a result, we had to use our brain and “figure it out” to develop first-principles, engineering-based solutions. 

The clients also had few reference points and were forced to look at the first engineering principles. That was the basis for deciding whether to proceed. The Sydney Water Corporation (now Sydney Water) was an early adopter of HDD technology. It is a major reason technology has grown into a substantial industry here in Australia. To its credit, it embraced many failures in the early days. Still, the HDD industry improved by embracing and learning what went wrong. It has changed practices, calculation methods and construction techniques. Sydney Water is one of the biggest users of HDD technology.

These days, running a pipe hoop stress check is normal practice. There hasn’t been a collapsed HDPE pipe for a long time. 

But from my firsthand experience in the early 1990s, I know there were a few. 

Despite these setbacks, the industry embraced the failures and worked out solutions and what would develop into industry best practices. Some notable Australian achievements in this period included: 

  • 1998: Several 1100 m long bores drilled for Telstra in sandstone.
  • 1999: An Australian contractor was the first to forward ream large-diameter granite bores using downhole motors. 
  • 2001: The first HDD bore in the world, over 2000 m, was drilled under the Tamar River in Tasmania. 
  • 2005: Sydney Water drilled dual 2500 m long bore holes in the Blue Mountains.
  • 2013: A pipeline was installed across the Narrows to Curtis Island at 2500 m. 

Many of these were the world’s first, industry-leading bores. Since then, bigger and longer bores have been drilled worldwide. Many of these bores have exceeded 3,000 m and in some cases, extended further. 

Horizontal directional drilling – now

Has the HDD industry lost its industry-leading way in the past 10 years or so? I think, yes.

In Australia, bores at 1500 m or longer have been increasingly rare in the past ten years. A bore close to 2,000 m was completed for Caltex in 2014. There are now few industry-leading long bores being drilled relative to other parts of the world. 

Given the great start, it begs the question, why did it stop? The Australian HDD industry seems to have stopped innovating, stopped pushing the boundaries, and stopped using first principles engineering to deliver unique solutions. Don’t get me wrong, the industry’s size has grown, and there are many more projects than before, but very few could be considered highly complex or “interesting”.

The Australian industry is doing a lot of 100 to 500 m HDPE pipelines with straight alignments daily. Such work is excellent but is not developing our industry and its people. 

One reason is that asset owners have become overly reliant on industry design engineering professionals who do not have the long, more challenging bore experience. As a result, the advice customers get is primarily from people without long bore experience. They only know how to push and advise on what they know. 

Small and simple is not wrong, but it’s not keeping our industry at the cutting edge. It does not allow stakeholders to fully utilise the technology, maximise value and deliver more optimal solutions. 

Infrastructure and asset owners need more faith in selecting a contractor that can provide a full suite of services. They should be working with contractors that design, engineer and install complete turnkey HDD delivery capabilities. 

Adding to this challenge is the HDD knowledge and experience of on-site asset owners and principal contractor representatives. They often believe they know better than experienced HDD contractors. It can create an impediment to the delivery of the HDD works in the lowest risk and better value way. 

Opportunities to save time and cost for the project’s overall benefit are missed if there is unnecessary and uninformed pushback on changes proposed by experienced contractors. 

The other big problem is when the asset owner conceptualises a pipeline project and then engages a large engineering design firm to develop the detailed design. The trenchless component of projects does not necessarily get allocated the requisite skills and priority required to optimise trenchless solutions and methods to provide significant value to a project. 

This is where we end up with a poorly conceived job for the contractors to deliver. 

Neither the consultant nor the graduate engineer has the knowledge or the experience to suggest a less conservative, potentially innovative design. 

Occasionally, consulting engineers will have the foresight to go to a contractor to ask for help. Contractors are often reluctant to give out clever or innovative solutions. They have no guarantee that they will win the project and that others will benefit from their unpaid time and ideas. There must be a better way of doing things.

Horizontal directional drilling – Future

HDD Engineering strives to fill this void and develop our industry, starting with innovative engineering solutions first principles. With 25-plus years of boots-on-the-ground HDD-specific construction experience, Maxibor provides key support to big design houses. They can enhance their initial designs without issues of probity and contract expectation associated with contractors. 

As projects progress, asset owners and their project engineering consultants increasingly reach out to specialist HDD designers and contractors. 

Their experience in long bores ensures the development of innovative trenchless solutions for complex project challenges. This is the approach adopted on the Sydney Water Refresh Vaucluse Diamond Bay project. Comdain is working with Maxibor and HDD Engineering to develop a constructive design for this landmark project, including a 1.85 km pipeline. 

For more information visit maxibor.com.au

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