Horizontal directional drilling (HDD) is a technique used to install underground pipelines and cables without disrupting the surface. However, the process can be complicated and may result in issues, including the breaking of the starter rod or adapters. In this article, we will discuss the reasons behind the breaking of starter rods in HDD operations.
Overbending: Overbending is a common cause of starter rod failure. The rod is designed to bend to a certain degree, but excessive bending can cause the rod to fracture. Overbending is often caused by incorrect steering or alignment, rough terrain, or improper backreaming.
Fatigue: Fatigue is another common cause of starter rod failure. The repeated bending and straightening of the rod during the drilling process can cause it to weaken over time and eventually fracture. To prevent fatigue, it's important to use high-quality starter rods that are properly maintained and inspected regularly.
Defective manufacturing: Defective manufacturing can also result in the breaking of starter rods. The rods must be made to exact specifications and tolerances to ensure they can handle the stresses of the drilling process. If a rod is manufactured with a defect, it is more likely to break during drilling.
Incorrect usage: Using the wrong type of rod for the job or using a rod that is not compatible with the drilling equipment can result in the breaking of the starter rod. It's important to choose the right rod and use it correctly to prevent failure.
Wear and tear: Wear and tear is another common reason for the failure of starter rods. Over time, the rods can become damaged or worn, reducing their strength and making them more likely to break during drilling. Regular maintenance and inspection can help prevent wear and tear.
In conclusion, the breaking of starter rods in HDD operations can have significant consequences, including the need to halt drilling, repair or replace the rod, and incurring additional costs. To minimise the risk of failure, it's important to use high-quality starter rods, maintain and inspect them regularly, and use them correctly. The quality of the starter rods depends on the non-metallic inclusions inside the steel and the proper heat treatment in the computer controlled furnaces.