man working on a drilling operation

Your guide to horizontal directional drilling (HDD)

Sometimes you need to drill beneath a road, a waterway, or some other obstacle that creates an engineering challenge for those used to downward drilling. Through the process of horizontal directional drilling (HDD), you can get your project done without disruption. But what exactly does HDD entail? Let’s explore this useful technique, the tools required to make it happen, and the reasons why it’s become such a popular drilling method.

 

If you need drill bits for your HDD operation, OK Bit has what you’re looking for. We offer a huge variety of new and rerun HDD bits. If you know what you’re looking for, contact us today to see if we have your bit in stock. If you aren’t sure, our experts will be happy to advise you on the best tool for the job.

 

How does horizontal directional drilling work?

There are three primary steps to horizontal directional drilling:

 

  1. Pilot hole drilling

    You’ll start HDD by drilling a small diameter pilot hole. Next, you’ll pump drilling fluid through the drill pipe to the bit, where high-pressure jets will help the bit grind soil ahead of the drill stem. This fluid carries cuttings back to the pit at the entrance of the drill rig.

  2. Pre-reaming

    Next, you’ll pre-ream the pilot hole until it’s a sufficient size to install product lines. You’ll pull the reamer back and rotate it while pumping drilling fluid, which will cut and remove debris to make the hole bigger. Additives like Bentonite are often used to ensure a stable hole.

  3. Pipe pullback

    Once your hole is pre-reamed, it’s time to pull back the pipe. Your reamer and drill rod will be able to swivel, preventing any torsional stress from the rotating drill string’s transfer to the product pipe.

What kinds of projects is HDD good for?

HDD is the best technique for installing a variety of types of underground infrastructure. It’s commonly used for:

 

  • Telecommunication cables
  • Fiber optic cables
  • Oil and gas pipelines
  • Water pipelines
  • Sewer pipelines
  • Electrical cables

 

If your project doesn’t fit any of the above categories, that doesn’t mean HDD isn’t your best option. Because of its versatility, the drilling industry is finding new applications all the time. Our experts can help you decide if it’s right for you.

The advantages of HDD:

  • Uninvasive – HDD allows you to install pipes and other utilities underground without disrupting anything above them on the surface. This is why it’s the most popular method for drilling in urban and suburban areas.

  • Easier to get permits – HDD creates less of a disturbance than the trench method and requires less equipment and people, so getting permits is a simpler process.

    • Cost efficient – For most projects, HDD is also cheaper than alternatives. You need fewer workers, less fuel, and fewer pieces of equipment. Additionally, there are little to no costs involved with restoring the surface after installation.

  • Faster Horizontal drilling is more efficient, so the process is faster. You also don’t have to spend time restoring the surface afterward. Because the pipeline is deeper than with the trench method, you’re also less likely to have to fix it or do maintenance.

What are the best soil types for HDD?

Soil type plays a large role in the success of horizontal directional drilling. Soft soils do best, including clay and sand. However, if soil is too soft, this can make steering the equipment more difficult and increase risk of hydraulic fracturing.

 

Hard rock can work well too, but it takes longer and needs heavier-duty equipment. Soil with a lot of cobbled rock or gravel, however, can make your equipment more difficult to steer and more unstable. This increases your risk of drilling fluid return.

 

Choosing the best HDD drill bit for the job

Finding the right HDD drill bit can be intimidating. There are a ton of different kinds, including PDC bits, milled tooth, TCI roller cone bits, drag and shear type bits, and point attack bits. Each of these bit types has its own IADC code and set of attributes that can get more detailed than you’ll likely need them to.

 

Choosing the right bit is typically a four part process:

  • Collect information about drill site – Start by doing an on site survey. Contact local authorities, water well drillers, construction companies, and anyone else who might be important and able to give you the information you need. The more you know, the more confidence you can have in your decision.

  1. Identify soil category – Take samples of the soil and analyze its materials. The texture and hardness will help inform what the right drill bit for the project will be.

  2. Choose a drill bit based on category – HDD bits go from softer to harder in descending order. If you need help figuring out what the right bit is for your project and soil type, our team can help you analyze your information and find the perfect bit.

  3. Adjust your bit as needed – You may find through the drilling process that soil type is inconsistent or other issues exist you need to adjust for. Analyzing return characteristics can help you know what adjustments might be needed.

 

OK Bit has the Horizontal Directional Drill Bits you need

If you’ve decided HDD is the right drilling method for your project, OK Bit can supply you with whatever bits you need to get the job done. If you aren’t sure if HDD drilling is the best choice or if you need help choosing a specific bit, our expert staff will be happy to help. Contact us today.

Tricone Drill Bit Vs. PDC Bit: Which is Right For You?

If you work in the oil and gas industry, it’s vitally important to always choose the right drill bit for the job. A poor choice might reduce your efficiency, but it also might have disastrous consequences that will end up costing you far more than the bit itself.

 

Two of the most popular choices for industrial drilling today are the tricone drill bit and the PDC bit. Both of these options have their pros and cons, so the right choice comes down to your operation’s unique needs. Let’s explore the strengths and weaknesses of these two options so you can help make the best decision.

 

If you need a tricone bit, a PDC bit, or any other type of industrial drill bit, contact OK Bit today. We’ll let you know if we have what you need in stock. If you aren’t sure what you need, our experts will be able to guide you.

Tricone Drill Bits

Tricone bits were invented in the early 1930s by Hughes engineer Ralph Neuhaus, and in the near century since, they’ve become a mainstay of all types of industrial drilling operations. Tricone bits are named for their three moving roller cones which require lubricated bearings. 

 

They’ve been tested time and time again, and many professionals consistently find them to be the best options for a wide variety of operations. To support this, engineers have repeatedly improved the design as technology evolved to allow for the addition of innovations like tungsten carbide inserts and sealed journal bearings.

 

Although rival PDC bits excel in many rock formations, tricone bits are still the best choice for drilling projects involving gravel, limestone, dolomite, and most other formations that aren’t homogenous, consolidated rock.

 

Issues can arise with tricone bits when they are worn out prematurely. This can happen when the bit is over-rotated. When you buy a bit from us, we’ll always advise you on ways to extend its life as long as possible. While tricone bits are less expensive than PDC bits, that won’t mean much if you have to replace them far more often.

 

Tricone bits work well in both soft and hard formations, but it’s important to choose the right tricone bit based on PSI. Overall, tricone bits can handle a range of 4,000-40,000 PSI. Since this is a massive scale, you can use this as a quick reference:

 

  • Soft formation tricone bits: 4,000-8,000 PSI
  • Medium soft formation tricone bits: 8,000-15,000 PSI
  • Medium hard formation tricone bits: 15,000-25,000 PSI
  • Hard formation tricone bits: 25,000-40,000 PSI

 

Pros of Tricone Bits

  • Extremely versatile
  • Good for both soft and hard rock formations
  • High impact resistance
  • More control
  • Low-cost initial investment
  • Time-tested

Cons of Tricone Bits

  • Shorter lifespan
  • Slower than PDC bits
  • Can lose parts in boreholes
  • Require lubrication

PDC Bits

Polycrystalline diamond compact bits have existed since the early 1970s, but they’ve only recently gained traction for water well and HDD purposes. This delay was mostly for financial reasons. While they started out as prohibitively expensive for most drillers, they’ve slowly become more and more affordable for operations of all sizes. Now they’re some of the most widely used bits in the world.

 

The most notable difference between the PDC bit and tricone bit is that the PDC bit has no moving parts.  PDC bits use fixed heads, and they’re made through a combination of tungsten carbide and artificial diamonds fused under pressure and heat. There are a few different body styles, but the “bullet head” variation is most common. PDC bits are generally faster than tricone bits, and they come in two types: matrix-body and steel-body. Matrix body bits are a little more expensive, but they are often more durable and require less maintenance.

 

One benefit of PDC bits is their ability to excel in soft rock. Most rock drill bits, including tricone bits, are designed to work well on hard rock, but they often suffer when applied to very soft formations. In general, PDC bits can work well in rock with a PSI between 2,000 and 30,000. Depending on your hardness, you’ll likely find that different amounts of blades are ideal. There’s some variation, but this can act as a quick reference guide:

 

  • Three blades: 2,000-8,000 PSI
  • Four blades: 6,000-11,000 PSI
  • Five blades: 8,000 to 20,000 PSI

 

Pros of PDC bits

  • Fast and safe
  • PDC bits have a long lifespan, so even if they cost more upfront, they may be the cheaper option in the long run. For this reason, they’re often the better choice for large-scale operations.
  • Because they have no moving parts, it isn’t possible to lose parts in the borehole during an operation. The same can’t be said of tricone bits.
  • PDC bits can achieve a higher rate of penetration than tricone bits under the right circumstances, lowering the overall cost per foot.
  • They work well in both soft and hard rock formations.

 

Cons of PDC bits

  • Cutter can break in high impact formations
  • Don’t work as well as tricone bits for very hard rocks

 

O-K Bit has the drill bits you need

Ready to order the bit you need? Feeling lost? Either way, we can help. Contact OK Bit today. We’ll let you know if we have what you need in stock. We can also customize drill bits for your operation. If you aren’t sure what you need, our experts are always happy to help.