Complete Guide To Directional Drilling | Types, Advantages

Complete Guide To Directional Drilling

Directional drilling and HDD drilling are the techniques of drilling a hole in the earth that goes vertically or horizontally at an angle to the surface, eventually intersecting with a place that requires an extended vertical reach, such as an oil well. This technique is invaluable to the professionals in the industry. It is especially used by contractors and engineers to access gas reserves and oil wells.

Complete Guide To Directional Drilling | Types, Advantages

What Are the Advantages of Directional Drilling?

  • Eliminates Constraints

Directional drilling eliminates certain constraints on where wells can be located. This can lower costs and shorten the time to drill. It also often lowers environmental impact and risk because it avoids having to dig up as much land for good construction. 

  • Good For Soil

It also reduces the disturbance caused to the soil by the drilling process, this makes the newly made reserve for either oil or gas much more valuable. Fresh soil makes it even more possible for agricultural or residential projects to take place, which would appreciate the value of these properties. 

  • Protects Groundwater 

It also helps reduce the contamination of groundwater resources by drilling mud and cuttings, this is a bonus for most people. So all in all it is a great technique for any construction company that also emphasizes keeping the surrounding environment in the best shape while working on very high-value projects.

  • Horizontal Drilling

It also allows the drilling of horizontal wells, which can lessen the costs associated with traditional vertical methods or multiple wells.

However, most of these advantages only come from choosing a directional drilling company that has the proper equipment, knowledge and attitude to make it happen. There are many different kinds of  HDD drilling companies out there, but some are better than others. 

What Are the Different Types of Directional Drilling?

The different techniques include wireline, slickline, cable tool, and auger drilling. The type chosen by the drilling company will depend on the soil conditions as well as the depth of the well. Let’s get into some detail about these techniques.

  • Wireline Directional Drilling

This is a more expensive method of directional drilling. It involves the use of a heavy, rigid steel cable that is pulled through the earth. The cable is then placed through a hole into the ground and it’s secured using various means.

  • Slickline Directional Drilling

This type of method is often used in relatively soft soil conditions where deep holes are difficult to drill by other methods like an auger or cable tool drilling but wireline drilling will be too expensive. A special kind of string called slickline can be used for this purpose which is made from polypropylene fibre and is coated with polyethene glycol (PEG).

  • Cable Tool Directional Drilling

This is used for drilling at hard and firm soil layers. The cable is pulled through the ground like a large drill bit made of high-strength steel. It also helps reduce ground disturbance as well as stabilize formations that tend to be unstable 

  • Auger Directional Drilling

This type of directional drilling is meant to create holes that go vertically into the earth while being able to hit solid rock all along the way. This method involves using an auger, which is usually wood or metal, and a long handle that looks like an old-fashioned hand drill (precisely the same principle).

What are the Disadvantages of Directional Drilling?

  • Might Not Be For Small Businesses

Directional drilling is time-consuming and utilizes expensive equipment, a lot less than what other techniques require for the same process but still, it’s expensive enough. This could be a big challenge for small and medium-scale small business owners.

  • Needs Proper Equipment And Experience

The cost of equipment is not the only issue that small business owners need to consider. Other factors need to be taken into account, like the operator’s experience in the business. Directional drills are also highly technical and can be very hard to operate even by experienced workers. 

  • Depth 

The directional drilling might not be able to reach the desired depth needed for a well, thus, it may not be possible for it to reach valuable deposits and reserves underneath the earth’s surface.

  • Damage

Directional drilling could cause land damage and affect properties near the wells by being noisy or leaking fluids from pipes and cables used during the drilling process.

How Is Directional Drilling Taken Out?

Step 1

The directional drillers start with a core barrel, which has a rod that extends into it from the outside. The rod is inserted into the ground, and through this rod, a drill string will go deep into the earth. After having gone as deep as they wish to go, they will withdraw their tool and cut off the drill string. This is to exact gauge where the well is. This process is called going vertical. 

Step 2 

They will then place a cable called slickline on the ground. They use this cable to lower the bottom hole into place at the desired depth of a well. The cable is made of polypropylene fibre and has a coating of polymer ethylene glycol on it so that it won’t be damaged easily, being kept under strain all the way.

Step 3

After this, the directional drillers will then use a cable tool to drill into and complete the hole with precision.

Step 4

Then they will take out and cut off all the tools used during the drilling process.

Step 5 

Then they will put back all their tools while protecting them on an aluminium table or using a containment device to keep the soil in place. The operator may also use special resin shoring to keep the soil in place. This is because some of these soils have a very different chemistry than others and internal pressure can be created, thus destabilizing them as well as causing ground stress beneath them. Shoring up for stability prevents this from happening.


Directional drilling companies are invaluable to many industries because they’re specialised companies that know how this technique works. Hiring one would most definitely help with all the resource and project management that needs to be considered. A technique made for those who construct for the future.

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"Structural Engineer" with over 5 years of experience in estimation, structural design, and surveying. I am passionate about using my skills to create safe and sustainable structures. I am also a keen writer, and I enjoy sharing my knowledge and experiences with others.