Common Problems and Solutions in the Basic Operational Use of Drill Rods

Date: Feb. 28, 2024

Drill rods are steel tubes with threads on the tail, used to connect drill rig surface equipment and drilling/grinding equipment or bottom hole devices located at the bottom of the drilling. The purpose of the drill rod is to transport drilling mud to the drill bit, and to raise, lower, or rotate the bottom hole device together with the drill bit. During normal use, some problems may arise, and below are 5 common problems in the basic operation of drill rods:

1. Drill rod loosening

Newly processed and assembled parts have geometric shape and fit dimensional deviations. In the initial use, due to impact, vibration, alternating loads, and the impact of factors such as heating, deformation, and rapid wear, the originally tightened parts may become loose.

2. Rapid wear of drill rods

Due to the impact of factors such as the processing, assembly, and adjustment of new machine parts, the friction surface is rough, the contact area of the mating surface is small, and the surface pressure condition is uneven. During the operation of the machine, the concave-convex parts on the surface of the parts interlock and friction, and the metal debris that falls off acts as a grinding material, continuing to participate in the friction, which further accelerates the wear of the mating surface of the parts. Therefore, the wear of the parts (especially the mating surface) during the breaking-in period is easy, and the wear speed is fast. At this time, if the machine is operated under overload, it may cause damage to the parts and produce early failures.

3. Leakage of drill rods

Due to the loosening and vibration of the machine parts and the heating of the machine, leakage may occur at the sealing surface and pipe joints; some casting, processing, and other defects are difficult to find during assembly and commissioning, but due to the vibration and impact during operation, these defects are exposed, resulting in oil (water) leakage. Therefore, leakage is prone to occur during the breaking-in period.

4. Many operational errors of drill rods

Due to insufficient knowledge of machine structure and performance (especially new operators), operational errors can easily cause failures, and even mechanical accidents.

5. Poor lubrication of drill rods

Due to the small clearance between newly assembled parts and the difficulty in ensuring the uniformity of the mating clearance due to assembly and other reasons, lubricating oil (grease) is not able to form a uniform oil film on the friction surface to prevent wear. This reduces lubrication efficiency and causes early abnormal wear of the parts. In severe cases, it may cause scratches or bites on the friction surface of precision-fit, leading to failures.