Choosing the Right Drilling Rig

A drilling rig is a type of construction equipment used to make holes in the earth’s surface. They can vary considerably in size: they can be massive structures or light enough to be moved manually by a single person.

Drilling rigs can take samples from mineral deposits as well as test the physical properties of rocks, soil and groundwater. They can also be used for underground installations: tunnels, shafts or pipes.

View drilling rigs

  • How to choose a drilling rig?

    Epiroc drilling rig
    Epiroc drilling rig

    You could need a drilling rig for a multitude of applications, for example to drill a well to access a natural resource (water, oil, geothermal energy, etc.), to build foundations, to make blasting holes in a mine, to take samples from the ground, etc.

    It is necessary to determine what the drilling rig will be used for, as well as what kind of terrain it will mainly be operating on. Depending on the terrain, you can choose between different types of drilling rigs: rotary drilling rigs, percussion drilling rigs, down-the-hole drilling rigs, top hammer drilling rigs (with high hammer), etc.

    In order to make the best choice, it is important to determine whether the drilling rig will be used for your core business or for occasional operations, and in particular whether you want to take advantage of the latest innovations or whether a machine that has proven its worth over several decades might be suitable for you.

    Safety, reliability and ease of use are also important elements to consider and are directly linked to each other. A machine that’s reliable and easy to operate, when used according to the manufacturer’s recommendations, increases user safety.

    It is also important to define the type of mobility you will need. There are autonomous crawler drilling rigs and truck-mounted or trailer-mounted drilling rigs that need to be powered by a generator or the truck that carries them.

    Once you have determined the type of machine you need, you can calculate the size required according to the diameter and depth of the borehole.

  • When is drilling necessary?

    Many jobs require drilling, for example:

    Drilling is most often done vertically, but it can also be horizontal or directional, for example for the placement of anchors.

    Some types of drilling:

    • Well drilling
    • Geothermal drilling
    • Pile drilling
    • Micropile drilling
    • Blast hole drilling
    • Continuous flight augering
  • What drilling technology should you choose?

    Drilling type Soil type Comments
    Rotary drilling Soft rock Significant depths up to 5,000 meters
    Possibility of inclined or horizontal drilling
    Down-the-hole drilling Hard and cracked rock (limestone, granite, etc.) Depth up to 4,000 meters
    Top hammer drilling Consolidated land Small diameter (150 mm maximum), shallow depth
    Able to do inclined drilling
    Auger drilling Clay, clayey sand, gravel Depth of a few dozen meters
    Core drilling All soil types Drilling for soil analysis
    Able to do inclined drilling
    Percussion drilling Hard rock: sandstone, limestone, shale Depth up to 100 meters
    Pipe Jacking Clay, clayey sand, gravel Installation of horizontal or vertical pipes


    Rotary drilling: This type of drilling digs a hole by grinding the rock with a tool under the effect of weight and rotation. It is mainly used in oil production. The cuttings are brought to the surface under the pressure of a drilling fluid that is injected into the drill string. Drilling fluid also helps consolidate the walls of the borehole, so it is not necessary to case it as the operation progresses.

    Down-the-hole drilling (rotary percussion drilling or rotary hammer drilling): this type of drilling uses drilling rigs that drill with a rotary cutter (drill head) and hammer the bottom of the hole with a pneumatic hammer. The excavated material rises to the surface under the pressure of the compressed air used for the hammer. These drilling rigs are powerful and have high drilling rates, especially in rock. For artesian wells (wells where water naturally rises to the surface under groundwater pressure) or geothermal drilling, an air injection at the end of the drill pipe pushes the water up the borehole, allowing the operator to immediately determine the water flow encountered. This type of drilling is used for hard and cracked ground up to 4,000 meters deep. When the drilling bit is eccentric, the drilling can be done with a casing advancement system (installation of tubes by gravity) which reinforces the hole as the drilling progresses.

    Top hammer drilling: this type of drilling uses drilling rigs that also operate on a percussion system, but one that remains outside the borehole. They are mainly used for small diameter drilling, for example for mineral exploration or the installation of tie rods in rock. This system is used for shallow boreholes, as there can be significant deviation due to the structure of the ground drilled through. These drilling rigs can operate in any direction however.

    Auger boring: This is a type of rotary drilling using a worm screw (the auger). This type of drilling is mainly used for unconsolidated clay or sand terrain. The excavated material is directly brought to the surface by the worm screw. For deep drilling, it may be necessary to regularly raise the auger to empty it of its excavated material.

    Core drilling: Core drilling is similar to rotary drilling, but it uses a crown to extract a sample, called a core, inside the tool.

    Percussion drilling: consists in breaking the rock by dropping a tool, the drill bit, by gravity. This type of drilling can only be used vertically. To prevent the borehole from collapsing, it is necessary to case it as it is drilled. The cuttings are reassembled as soon as they interfere with drilling by replacing the drill bit with a flap valve bailer. The flap valve bailer is a type of tube equipped with a tilting flap in the lower part. This tilting flap allows the tube to be filled with excavated material which is then transported to the surface.

    Pipe jacking: is mainly used to install horizontal pipes. The tube is pushed progressively by percussion, the excavated material being removed at the end of the drilling operation either by water injection or with an auger. This technique is used in particular to avoid transmitting vibrations to the surrounding buildings or to avoid digging a trench.

  • What type of drilling rig should you choose?

    Hydra drilling rig
    Hydra drilling rig

    There are two main types of drilling rigs: autonomous crawlers and truck or trailer-mounted.

    • You will need to choose a crawler if it needs to move at a low speed over unlevel areas or on very loose ground. The stability of the drilling rig depends on the surface area of the tracks. As such, the wider the tracks, the more stable the drilling rig will be. However, wide tracks will tend to wear out more quickly and break down the ground when moving, especially when turning. The travel speed of a crawler drilling rig is about 4 km/h. They are therefore better adapted for work that requires little travel.
    • Truck or trailer-mounted drilling rigs are not autonomous in terms of movement or their energy source, which may come from the transport truck or an independent generator. However, they are much cheaper than crawler drilling rigs.
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  • Vivian Black says:

    I love that this article talked about down-the-hole drilling and how it uses rigs that drill with a rotary cutter. My husband is looking for a drilling service that can help his contractor company with its foundations. We will keep these tips in mind as we search for a professional that can help them best.

  • Win McB says:

    We’re somewhat new to the business of well drilling, so this is a great article to read, very informative. It would be great to get a crawler for jobs with uneven ground or maybe if there’s a lot of mud. We haven’t ever got the truck stuck, but a few months ago it probably would have been better to have a crawler rig on the job site instead of our truck. I guess that’s something I might invest in come the future…

  • Kristofer Van Wagner says:

    I appreciate that this post explained there are different types of drilling rigs that we can choose from. The other day I overheard my neighbor, who is planning to have his house renovated, wanted to drill the house’s foundation. I will share with him this article so that he will be more informed about which rig to choose.

  • Jack William says:

    Over the years, L&D Micro Tunnelling has worked on many projects involving soft and hard rock drilling and other types of drilling in Victoria.

  • Franklin White says:

    Thank you for explaining how you need to make sure you get a drilling rig that can be used to drill what you need and stand on the ground that you have. I have always been told that it is a good idea to get a water well. I think I might but I would definitely need to make sure the company I hire has the right drill.

  • Kristofer Van Wagner says:

    I like that this post mentioned that commercial drilling requires the right skills and expertise to carry out. My sister was asking about commercial drilling. I will remind her to hire an experienced driller.

  • Megan Alder says:

    I found it very interesting to know that there is a variety of different drilling jobs that can be performed, and how each works differently for what you’re looking to do. My husband mentioned that we will need drilling services for a house project he has, so I wanted to know more about the matter. I will definitely let him know that I read about the different drilling jobs and how each helps us differently.

  • Levi Armstrong says:

    It’s great that you mentioned that drilling is necessary to access groundwater and build a water well. My grandpa wants to have a water well on his ranch for irrigation purpose. I’ll tell him to start looking for a reputable drilling service so he can have one constructed on his property soon. Thanks!

  • Braden Bills says:

    I want to get a water well drilled, but I’m not sure how to go about it. It makes sense that I would want to get a professional to drill it for me. That seems like a good way to put things together.

  • Tex Hooper says:

    I didn’t know that rotary percussion could dig a well. I need to get a contractor to dig for me. I’ll have to make sure that I get someone with the right equipment.

  • Tex Hooper says:

    I like what you said about getting the worm screw. My office is in need for durable steel materials. We’ll have to get a bore.

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