HDD Eldorado Park (River Crossing)

Our longest HDD crossing for the year started off in Eldorado Park where we were tasked with installing a 450mm HDPE pipe for over a distance of 170 meters in one continuous pull.

The area was in a wet land and included a river crossing. Our time period was relatively short as we wanted to complete the crossing before the rainy season. The new pipeline was to replace an old overhead steel pipeline that was leaking fresh drinking water at many of the pipeline joints.

We established our American Auger DD-10 which has a maximum pullback/thrust of 45 metric tons with 18 982NM of torque. For this project we reached a peak pullback of 7 tons (15%) and a peak torque of 4 500NM (23%).

The ground conditions were non-reactive clay which can be incredibly difficult to drill in if the incorrect combination of chemicals are used, clay tends to stick to the HDD tooling which results in balling of the tooling which increases both torque and the pullback tonnage, which could cause the new pipeline to get stuck which renders the bore completely useless with the loss of equipment and new product pipe, and inevitably breaks equipment which delays the project.

Initially we expected this crossing to take 12 days from pilot bore to pipeline installation, however we installed the new HDPE pipe in 5 days. We maintained approximately 1.5 meters of cover from the depth of the riverbed (approximately 3 meters deep) and maintained approximately 1.8 meters from NGL after the riverbed until we reached the launch pit.