Use Of HDPE Pipe In Horizontal Direction Drilling

Horizontal Directional Drilling (HDD) is a construction technique where by a tunnel is drilled under an already existing infrastructure like road, rail track etc. or residential area or natural water resource like lake, pond or river etc. and where open trenching work is either not feasible or cost economics does not permit. A pipeline or other utility (electric or communication cable) is pulled through the drilled underground tunnel. The underground tunnel follows an arc line from the entry point, down under the special crossing area, and then resurfaces on the opposite side. Using advanced technology and highly trained technicians, a drill head guides the drilling pipe electronically to ensure the angle, depth, and exit point adhere to carefully designed engineering plans. Throughout the drilling process, the tunnel is kept open and lubricated by circulating a watery mud-slurry mixture, typically composed of about 95 percent water and 5 percent bentonite clay—a natural, non-toxic substance. The drilling mud also helps coat the walls of the tunnel and keeps them stable apart from removing drill cuttings. Time needed for drilling depends on the distance of the underground drill to be covered; the soil geology of drilling area; the pipeline’s diameter; and, the progress of drilling operations. Once the HDD is done, the required pipe or utility is pulled though the drilled hole.