Keys to a smooth running HDD operation

Success in the HDD business is about more than boring a stable hole and completing a successful pullback. It's about running your entire HDD operation like a well-oiled machine. Here are five ways we've seen successful HDD companies make businesses function more smoothly and create lasting success, followed by an example of what to look for in on specific type of tool, the backreamer. 

1. A quality crew 
Your equipment is only as useful as the people who operate it. Mixing and matching crews with various levels of experience and different personality types can slow down a job. Hire teams of experienced drill rig operators and locators who either come as a pair or have been proven to work well together. When a drill operator and a locator work together regularly, they end up developing their own communication and production rhythm that helps you drill further faster.

2. An assortment of tools 
It's tempting to stick to the OEM tools that come with your rig but filling out your toolshed with bits, reamers and other condition-specific parts will save you time, frustration and expense down the line. Start to acquire high quality directional drill products as you undertake different projects in various conditions. As you're bidding out jobs, pay attention to the materials you're likely to run into underground and invest in tools that have been proven to handle those conditions. Buying quality and maintaining your parts correctly will shave time off your jobs and save you in the long run.

3. Your distributor is a resource
Don't turn to your distributor only when you need a new part. Your local distributor is a wealth of knowledge and wants to share it with you. They love getting to know you and hearing about your challenges and successes. Speak to your HDD distributor contact frequently about the types of jobs you do and the products you use. Give them feedback and suggestions. Ask for their advice. Many times your distributor can provide you with cost-effective solutions to get the job done faster than you expected. Don't be shy. Capitalize on their experience because they know what works.

4. Get custom-made HDD tools
Sometimes the right tool for the job doesn't exist - yet. That's where your HDD tooling experts come in handy. While OEMs provide a range of parts and accessories, manufacturers of directional drilling products can take your idea, add their expertise, and output a custom backreamer or other tool designed specifically to handle the conditions of your job. Just like distributors like to get to know drillers, manufacturers of directional drill products, like Melfred Borzall, love to see how tools stand up to tough real-life drilling conditions and get feedback from the crews who use them daily. If you have a challenging situation that you're not sure your current tools can handle, don't hesitate to develop a relationship with a manufacturer who can help.

5. Standardize your tooling 
There's nothing worse than getting out to your job site and discovering that the threads on your tools don't match those on your rig. Tooling manufacturers or other after-market manufacturers of directional drill products can supply you with - or design and produce - a complete set of adapters that ensure that all your parts connect. Not only will you gain efficiencies in productivity but you'll get more mileage out of your entire equipment shed because you can use any tool on any rig.

Backreamers: the workhorse of every HDD drilling operation
Too many drillers make the mistake of thinking that one backreamer can do it all. The fluted reamer that comes with the rig is great, under certain conditions. However, drillers try to use the default drilling reamers in situations where a specialized reamer would increase production.
What can happen when you rely on the wrong reamer?

At best, picking the wrong backreamer can make your drilling proceed slowly and drag your efficiency way down. At worst, your reamer can snap off in the hole, causing you to stop drilling to retrieve it or forcing you to abandon the hole altogether and re-drill a new pilot. A reamer that pulls back too fast may cause road humping for which you will be on the hook to repair; too slow, and you get cratering.

All these scenarios eat up time and stall your progress. Broken backreamers require replacement of the original reamer, plus an investment in a reamer that is better suited for the job. Add on the extra cost for the rushed air freight to get the reamer to your jobsite as fast as possible and that's a lot of cash that you could have saved if you had the right reamer in the first place.

Before you decide which reamer you need for the job, think about the following factors.

Ground conditions: Know the type of material you expect to encounter before you drill your pilot. 

If you are drilling in ground that is unstable or sticky, like clay, you need a reamer with excellent mixing action and enough fluid pressure to make sure the material doesn't ball up or leave big chunks behind in the hole. 

For unstable conditions that face the risk of collapse, such as sand, you need to have an efficient mixing action that keeps the cuttings and the drill fluid mixed together to support the borehole wall, and not allow the sand to collect on the bottom of the hole.

Cutting action: The type of cutting action you'll need also depends on your ground conditions. 

Shale and soft limestone require backreamers with more cutters for fracturing material, then grinding it up. Softer ground, like clay or sand, requires fewer cutters or you risk balling up. 

Harder conditions like cobble or river rocks mean you don't need to break up baseball-sized cobble as much as you just need to push it out of the way. For these conditions you need reamers with a gradual, tapered body that help push the rocks aside. This is where a solid, tapered body reamer like the basic fluted or stacked plate reamer performs best. 

Finally, solid rock conditions need cutting action that pulverizes the rock as it's spinning, making small rock chips that are easier to pump out of the hole.

Rig size: Using an undersized tool (not the cutting diameter but the shaft it's built on) on a drill rig that is too powerful can damage the backreamer and stop your job. Choose a backreamer that is strong enough for the size of rig you're using. Don't use a 20,000-pound drill tool on a rig with 40,000 or 60,000 pounds of pullback. If you must mix and match, it's better to use a big rig reamer on a smaller rig than the opposite.

Drilling fluid volume: Always be sure you have plenty of drill fluid flow when backreaming. Pressure isn't as important as making sure you have enough volume passing through the shaft. If you're not using enough fluid, you're not going to be able to get all the cuttings out. Pulling back too quickly without enough fluid to carry the cuttings out of your hole can just push the material forward with the reamer, causing it to get stuck or create a speed bump. 

If you're using a reamer meant for a small rig on a big rig, the fluid holes in the reamer could be too small - not allowing enough flow to carry your cuttings out. 

The opposite applies, too. Using a big reamer with big fluid holes on a small rig means not enough pressure, limiting your flow and causing the whole thing to ball up.

Peter Melsheimer, Marketing Director at Melfred Borzall, has a degree in Mechanical Engineering and has been in the HDD industry since 1989.