Troubleshooting Tips

Published On: February 19, 2024By Categories: All Things Hammers and Bits, Drilling

Follow these tips to avoid downtime on the jobsite.

By LaTisha Shipman

No one enjoys a situation where you encounter downtime for any reason. It is often a frustrating moment that can be made even more frustrating when you can’t get in touch with anyone from technical support.

So, here’s a list compiled from various DTH hammer manufacturers regarding the troubleshooting of your DTH hammer in the event you have issues and can’t get in contact with someone or are out of cellphone range.

Problem 1.

My hammer won’t fire after I added a new piece of drill pipe.

Possible Causes

The hammer could be flooded out. This is particularly a possibility if you were below the water level when the problem occurred.

The hammer could also have gotten foreign particles inside and could be filled with debris.

Finally, it could be that too much oil drained down into the hammer, flooding it. However, you would have to be using a lot of oil for that to happen.

Okay, How Do I Fix It?

Flush the hammer clean with air, lifting up off the bottom of the hole.

Trip out of the hole and go through the hammer.

Make sure the hole is “clean” before uncoupling the pipe.

Use a non-return float valve if drilling in deep water. This will keep water from traveling up the drill string.

Problem 2.

My hammer will fire on the surface, but it won’t fire in the hole.

Possible Causes

The flushing holes on the drill bit could be blocked, especially if you’re in clay.

Also, the formation may be too soft, not allowing the hammer bit to engage properly, which can prevent the hammer from firing.

What Do I Do?

Make sure the drill bit is clean and that the flushing holes aren’t blocked. If they are, clear those out. However, never look up into the bit while it is engaged in the hammer and do not try to do this while the bit is in the hammer over the hole or while the air compressor is on. Disconnect the hammer and the bit and then proceed to clear out the flushing holes.

Another option is to try increasing your RPM, and perhaps thrust, keeping full air on at all times.

Or you can try implementing a clay inhibitor or other additive such as Matex Hole Control to help keep the hole open and clean, and to keep the clay from balling up on your bit face.

Problem 3.

My hammer isn’t working consistently on the surface or downhole.

Possible Causes

There could be worn or broken parts keeping the hammer from firing. If you use a bit with a blow tube, it could be broken.

The hammer could also be assembled incorrectly or off-center. For example, the bit bearing could be installed upside down. While it is uncommon, this can happen even with a new hammer as people make mistakes. You can never remove the human equation from hammer assembly.

The hammer could also be contaminated with mud or other foreign particles.

Finally, the hammer could be flooded out with too much oil or water. The piston needs a good, clean striking face on the anvil end of the bit. Oftentimes water or sediment settles there, which can cause issues with the hammer not firing properly.

If the hammer has been in use for some time, you may need to check the wear limits.

What Can I Do?

Pull the hammer out, disassemble it, and inspect the parts to see if anything is broken. If the hammer isn’t firing at all, make sure the piston isn’t broken and make sure the blow tube isn’t broken or cracked.

Then reassemble the hammer correctly. Reference your hammer manual to install parts correctly.

Some parts, like the bit-retaining ring and bit bearing, might have a bevel on one end. It’s important to know which end goes where, as that can affect the hammer’s makeup and performance.

Remove any debris from the internal parts, clean them, oil them down, and then reassemble the hammer.

Also check to make sure your hammer lubricator is operating correctly. It could be that you’re using too much oil inadvertently.

Problem 4.

My hammer isn’t working at all—on the surface or in the hole.

Possible Causes

Not enough air is getting to the hammer. The hammer could also be assembled incorrectly or be contaminated with cuttings and trash.

You could also have worn or broken parts inside the hammer, or it could be a broken blow tube.

Finally, the piston could be seized.

What Do I Do?

Check your compressor. Is it working correctly? And when checking, never direct compressed air onto your skin, so do not check this by hand.

Check all the air hoses for leaks, kinks, or blockages. Make sure to use whip checks for safety. If the hose has been lying outside, critters could have made a nest inside.

Make sure the couplers are all matched up correctly. Using mismatched couplings can result in lower air pressure getting to the hammer.

Pull the hammer out, tear it down, and inspect the parts. Make sure the piston can travel freely. Then reassemble the hammer correctly.

If the hammer has been in use for some time, you may need to check the wear limits. As the hammer wears down over time, it cannot maintain the same pressure as a new hammer, and at some point, it needs to be retired. That is up to the driller’s discretion.

Problem 5.

My hammer isn’t drilling straight.

Possible Causes

This could be an issue with the formation being too soft for DTH drilling or the way the rig was blocked.

It could also be that insufficient air or no air is reaching the hammer.

Finally, the flushing holes could be blocked, the feed force could be too high, or your drill bit could be worn.

Proposal

Secure the mast and block up the rig if the formation is soft, making sure everything is level.

Make sure there is sufficient weight on the jacklegs and repair the jacklegs if needed.

Remove any obstructions before you continue drilling.

Reduce the feed force to the correct level when collaring.

Problem 6.

I’m not getting any cuttings out of the hole.

Possible Causes

The cuttings could be lost through fissures in the surrounding formation.

The cuttings could also be balling up on the bit face.

The cuttings could be too big or too heavy to be returned to the top of the hole, in which case they will fall back down and you can end up burying your entire string down the hole.

You could have broken carbide on the bit face.

Your operating pressure could be too low.

How to Fix It

Check the air pressure. Make sure the hammer is holding sufficient pressure to return the cuttings.

You might need to consider using a larger OD drill pipe or larger hammer-to-bit ratio and recalculate the up-hole velocity.

Use a lost circulation material or other additive to help stabilize the borehole, but make sure to use one compatible with DTH drilling. Otherwise, slow down until you are through the fissured area, lifting and flushing consistently.

You can mix a stiffer foam to aid in cuttings removal too.

If the problem continues after trying to remedy with fluids and additives, check the bit face to see if it is blocked or if there are missing buttons. You could be regrinding cuttings, and it might be time to put on a new bit.

______________________________________________

We’ve just scratched the surface with this column. There are so many things that can happen and so many troubleshooting
tips to pass on. I’ll continue this topic in the next All Things Hammers and Bits Column in the June issue of Water Well Journal.

Idea for a Column?
If anyone has a question or subject that they would like to see addressed, please contact me at latisha@drillingequipmentresources.com.

LaTisha Shipman is the Texas branch manager for Drilling Equipment Resources. She has more than 20 years of experience in the drilling industry, with most of that time spent working in manufacturing with DTH hammers and bits. She can be reached at latisha@drillingequipmentresources.com.

Read the Current Issue

you might also like