The Importance of Greasing the Rod String Following a Bit Change
May 28, 2020
By: Richie Gushulak, Product Manager / Design Engineer, Di-Corp
Why use Rod Grease?
The best drill rod in the world (which we just happen to believe we make) is a high performing one that is resistant to wear. But no matter what drill rod you’re using, Drill Rod Grease helps optimize both performance and longevity by increasing productivity during a string reinstallation and minimizing drilling issues during production drilling, each contributing to an increased product life.
Following a bit change or other necessary drill rod string removal, it is time to reinstall the drill rods back in to the bore hole in order to continue production drilling or to install other tooling. This is the time to apply rod grease to the outer surface of the rods as they are being added back in to the string. On a surface job, with each drill rod added, the string gets heavier and the rods want to drop with an increasing force. This weight forces the rods to slide across imperfections in the abrasive borehole wall and debris can be deposited in the annulus. In some cases, the two hard cylindrical surfaces can become wedged together, causing unnecessary damage and downtime should the drill rods become stuck. The bore hole is never perfectly straight and resistance to the rod string lowering occurs due to friction between the outer surface of the drill rod and the inside surface of the bore hole. Rod grease reduces this friction substantially by lubricating the contacting surfaces, decreasing the time required to reinstall the drill rods all the while minimizing damage to the product. Rod grease is good for productivity even when the rods aren’t turning!
Minimized Drilling Issues!
Due to the increased lubricity between contacting surfaces, there will be less inherent vibration, chattering and frictional resistance when drilling with rod grease. A more uniform angular velocity can be achieved and torque remains more consistent. When a variation in torque occurs, this is an indication that the joints are being subjected to load spikes and additional cyclic fatiguing. Additionally, the contacting, non-lubricated surfaces are much more vulnerable to premature failure and or wear.
Increased Drill Rod Life!
When you minimize the issues with reinstalling and drilling with a drill rod string you positively impact Rod life. This is because the product is being optimized by Drill Rod Grease. No other product can have the same unique impact on the life of a drill rod. Whether the drill rods are being manipulated axially or rotating under extreme torsional loads during drilling ops, Rod Grease improves performance and increases product life.
Not All Greases are Created Equal.
Earth Pro Big Bear Rod Grease is specially thickened extreme pressure grease with additives that provide corrosion, wear and oxidation resistance. Tackiness assures adherence to drill rods while providing superior resistance to water washing and centrifugal separation. It possesses the right degree of fibrous characteristics to permit easy smearing of the drill rods by hand. As the rods are lowered into the bore hole, an adhesive film is formed on the rods that is resistant to the washing action of the water and sludge containing rock cuttings. As a result, you can reduce drilling costs because rods are pulled for greasing less frequently. Download a Big Bear Rod Grease product sheet here.
Earth Pro Bio Bear Biodegradable Rod Grease from Di-Corp incorporates all the benefits of Big Bear Rod Grease but in format that’s great for environment sensitive applications. Not only does Bio Bear outperform other biodegradable greases, in field trials it has been shown to provide better wet rod adhesion than even some heavy metal fibrous greases. Blended from naturally sourced oil and non-toxic surfactants Bio Bear is firmer in texture, adheres better, and is less affected by cold and humid conditions than biodegradable competitors. This makes it an ideal sustainable choice for any rod grease application in any weather or condition. Learn more about Bio Bear Rod Grease here.
Applying drill rod Grease to the outer surface of a drill rod string following a Bit change or string removal is of paramount importance. The life of the drill rod string and the efficiency of the bore hole are both impacted tremendously by this one small detail. When a film of rod grease has been applied to the outer surface of a drill rod string, the drill rods can be reinstalled into the bore hole with less resistance and binding. Drilling becomes less finicky as the string torque is more manageable. Rod grease will extend the overall life of a drill rod, dropping the cost per linear unit drilled.