CALGARY – ENERGY – Drill rigs are machines that are used to create holes in the sub-surface of the earth. ‘Rig’ is a particular term used to describe complex equipment that is used to penetrate the Earth’s surface, so the machinery that fits under this description can vary quite dramatically. These are massive structures housing necessary equipment used to drill wells and extract oil, water and natural gas from the earth as well as sample materials such as mineral deposits and soil properties. These drilling rigs can vary dramatically in size – with smaller instruments that are used manually being called augurs – and are used both on land and offshore on marine based structures such as oil platforms.
Small to medium sized mobile rigs are typically mounted on trailers, tracks or tunnels and are used in mineral exploration and environmental investigations as well as blast-hole drilling and the construction of water wells. Large rigs, on the other hand, can drill thousands of meters through the Earth’s crust to create cavernous wells and are capable of drilling holes in deep water. These types of drill rigs are often operated from thousands of miles away from their supply base and are big enough to even accommodate living quarters and catering facilities for the crew.
The Different Types of Drill Mechanisms
It would be a mistake to assume that mobile rigs are small. In fact, auger drilling rigs can weigh as much as 100 tons and use the same technology as larger rigs that drill for oil offshore. Mobile and auger drilling rigs today are highly complex pieces of equipment and multipurpose exploration drillrigs are capable of performing core drilling as well as reverse circulation drilling, although these are not the only manual drill rig types that are used today.
- Air-Core Drilling
Air-core drilling utilizes compressed air to clear debris out of holes and is most commonly used in exploration drill programs. This type of drill can only drill to depths of 50 to 60 meters under the Earth’s surface and cannot penetrate hard rock. However, it is inexpensive and is highly effective at drilling into loose materials.
- Auger Drilling
Augur drills are circular and screw-like and by rotating they can bury themselves into soft ground and materials. It is the fastest as well as the cheapest drilling option, but it cannot be used into hard materials.
- Cable Tool Drilling
While this type of drill tends to be overlooked in favor of faster, more effective rigs and techniques, it remains the best option when drilling deep water wells. Rather than using rotation like auger drills, cable tool drill rigs use an up and down motion to chisel away at rock. While inexpensive, they can be slow and one issue that tends to slow down the process is that the drill needs to regularly be lifted out of the hole so that drill cuttings can be cleared out of the hole.
- Diamond Core Drilling
Fine industrial grade diamonds are used to create these types of drills, and by varying the diamond content and the material of the matrix these drills can penetrate many different types of rocks. They are often used to collect core and have a wide range of applications.
These are only some of the different type of manual drills that are used today, although the drilling industry is being developed all the time and new, more efficient designs may be arriving sometime soon. Today, drill rigs are often classified by the drilling method they use, their height, the power they use, the pipe they use, and by the position of the derrick – which is the framework that supports the drill.