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.
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.
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…
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.
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.
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.
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.
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.
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!
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.
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.