How Do HDD Contractors Run Pipelines Under Rivers?

underground boring contractorHorizontal directional boring is the first choice of contractors when it comes to drilling and installing pipelines by highways and waterways. But just how do contractors run pipelines under rivers and waterways in the first place?

Here we’ll go in depth about how underground boring contractors go about drilling efficiently beneath waterways.

It all starts with the pilot hole

A drilling rig is built on a movable chassis, but their size ultimately depends on the diameter of the pipe used in the project. The rig is controlled from a booth next to the rig that can be moved from job site to job site.

Underground boring contractors will start the HDD process by drilling a pilot hole from one surface point. A rotating drill head is then passed through the length of the crossing guided by a surveying system.

The pilot hole is smaller than the final pipeline width, but it’s made wider by the crew once they remove the surveying system and drill bit from the machine. After this is done, several reaming passes are run to make the opening wider.

Reaming on a prayer

Reaming passes are made by a device called a reamer that’s attached to a drill string that runs through the entire length of the tunnel. On the other side of the river or waterway, the second rig receives the reamer. The crew monitors the location of the reamer using a steel drill string.

The tunnel is pumped full of drilling fluid (a water/bentonite mixture) to prevent the area from collapsing or filling with soil. The drilling fluid passes through long sections of drill pipe into the drilling area where it carries soil and debris to the surface.

The final pass and pipeline installation

The final hole after the reaming passes is between 30% to 50% larger than the diameter of the final pipeline. Contractors will run a final pass with more mud to make sure the opening of the hole is clear of debris.

The reamer is then removed and the pipe is pulled into the reamed hole. Once the pipe is installed, the project is a success.

Looking for underground boring contractors for your project?

It’s estimated that there are 2.5 million miles of pipelines that transport fuel products in the U.S. from source to market. Horizontal directional drilling is the safest, efficient, and most cost-effective method for installing those pipelines.

If you’re looking for Texas underground boring contractors for your project, American Directional Boring is the underground drilling service for you. To learn more about our services and HDD contractors, contact American Directional Boring today.

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