In this short video by Skyview Productions, Mr. Electric shows how horizontal directional drillers work.
Horizontal directional drilling (HDD), also known as directional boring, is a trenchless method of safely installing an underground cable, pipeline, and service conduit. The process entails precise drilling along the predetermined bore path and back reaming the correct pipe.
There are three stages directional drillers work on for the entire process of HDD, including pilot hole drilling, pre-reaming, and pipe pullback.
Drilling a pilot hole of a small diameter is the first step in the process. The drillers use a drilling fluid that is pumped to the drill bit through the drill pipe. High-pressure jets help the bit in grinding the soil down the route of the drill stem.
The drilling fluid will then be transporting the cuttings back to the drill rig’s entrance pit. Depending on the shot’s complexity and size, the drillers can track the pilot hole in various ways.
The locator and operator will make adjustments to ensure the pilot hole stays on the chosen bore path. The amount of steering necessary and the current soil conditions will determine the pilot hole’s speed. When it reaches the exit point, the bit and beacon housing will be removed and replaced with a reamer.
Pre-reaming the pilot hole will widen its size, allowing the product lines to be installed. Finish watching the video to see the rest of the process involved in HDD.