With drill sites sometimes located in undeveloped areas, such as deserts, forests, mountains and even swamps, a project can be considered remote or hard to access due to various factors.
For instance, sites in a dense equatorial jungle or on steep mountainsides are considered hard to access because moving through trees, mud and on steep slopes presents logistical difficulties.
Meanwhile, sites that are hard to reach due to long distances to existing infrastructure, such as water-well drilling programmes in the African bush, are considered remote and hard to access because the drill team is isolated from services and supplies.
On top of the obstacles in regards to access and distance, these drill sites often require special equipment to overcome challenges such as extreme heat or cold, high altitudes, muddy or humid conditions, and difficult terrain.
Hence, when preparing to drill on remote drill sites, planning and versatile rigs are key, explain Thomas Way and Quentin Dulake of drill manufacturer Dando Drilling International.
"Extreme conditions, whether in terms of climate, ground conditions or geology, require well-designed rigs above all else.
"Drilling is very situation sensitive, and Dando addresses this fact through its modular approach to design. Key components on many models have been designed with a number of alternative options for rotary heads, engine power units, winches, mast extensions, canopies and track systems," says Way.
Dulake adds: "Careful planning is the key here. In the absence of a supply centre close at hand, you need to pre-plan the equipment that is used and accurately predict the requirement for drill bits, and other fast-wearing spare parts such as seals, chains and pump valves."
As most types of drilling, whether environmental, seismic, geotechnical or even for water wells, are done before a job site is developed and improved, drill sites are often difficult or impossible to get to with on-road trucks. Hence, while minimising the necessary transport is key to the success of a remotely located project, finding the most cost-efficient way of transport is equally essential.
Off-road expert ARDCO specialises in multipurpose carries for land and wetland.
Sales engineering manager Tim Niedzwiecki explains: "Track vehicles can sometimes traverse these areas, but they are slow, high maintenance and require at least some pre-existing path or road. ARDCO AMTs (articulated multi-purpose trucks) can get to the job site when the only road is no road."
To match various ground conditions, ARDCO vehicles can be equipped with a multitude of tyre options, such as wide-flotation tyres, sand tyres, logger grip tyres and more.
"Track machines are great for some applications, but you can't avoid the high-maintenance cost of the tracks and undercarriage components," says Niedzwiecki.
"If any part of the track system fails while you are stuck in a mud hole, it becomes extremely difficult to get it unstuck and repaired.
"The AMT doesn't have this problem - 4 or 6 tyres are a lot less to worry about than the multitudes of moving parts in a typical track undercarriage."
Using AMTs can also eliminate the need to create permanent roads when intermittent access is required over long periods of time, such as is, for instance, the case with remote oil wells, which require periodic soil sampling.
"Often, this means roads have to be maintained at significant expense, even though they are only used maybe once or twice per year. When these wells are no longer active, that is a cost burden most companies would rather not have," says Niedzwiecki.
"The ARDCO AMT machines can get to these sites with no pre-emptive path clearing required, saving cost and speeding up the process."
With the high dependency on the carrier's reliability, choosing a carrier that is supported in the local region is also important.
Many of Dando's Watertec 12.8, 24 and 40 customers in Africa, for example, often choose the IVECO Trakker 6x6 truck as their base "because of its outstanding longevity in the harshest environments, and also because it is well supported in the region", says Dando's Dulake.
When moving equipment over long distances outside regular infrastructure, creating compact and holistic drilling packages is key to decreasing costs and increasing ease and safety of the operations.
Dando frequently supplies water-well drilling rigs to customers in Africa and the Middle East, where distance from infrastructure is a primary consideration. Drilling a well in a rural African village, the team can be many hundreds of miles from workshop facilities, electricity, running water and fuel supplies.
"As a result, a drilling package such as Dando's Watertec 40 model, which has a large 900cfm/350psi compressor on board alongside a Gardner Denver 7.5in x 8in [191mm x 203mm] Duplex mud pump, is a preferable setup to one which requires individual trucks and power units for each of the ancillaries," explains Dulake.
"Having everything in place on the deck of the Watertec 40 reduces the amount of fuel and consumables required to be trucked in, reduces the need for long hoses connecting the units together, and increases the overall ease and safety of operation."
Nonetheless, most remote job sites require improved roads, with gravel or mats to get equipment and materials in and out.
Flexible and versatile carriers are key to creating those roads in the most economically efficient way.
For this purpose, ARDCO's AMTs can be configured as a dump bed one day, a flatbed for hauling mats the next, and a service bed for the remainder of the project.
This allows contractors to haul gravel and mats with one piece of equipment instead of two, and subsequently use the same vehicle to service their job site for the remainder of the project.
"This is a big cost saving from both a fleet size and logistical standpoint. If you need water or fuel on your project, you can swap out the flatbed on the truck for a fully equipped tank attachment with quick-connect hydraulics for powering the water or fuel pumps," stresses Niedzwiecki.
When it comes to sites that are remote because of limited access, such as dense jungle environments, there are broadly speaking two options: creating access by clearing obstacles such as trees and undergrowth, or adapting equipment to the surroundings.
The tendency is towards the latter for exploration programmes that prioritise low disturbance to the environment and reduced running costs.
Dulake explains: "Our bestselling exploration rig is currently the Multitec 4000 for this very reason. It is small and compact at only 1,600mm wide and so can easily navigate between trees with only minimal clearing of undergrowth required. Yet, it is incredibly versatile and powerful, ideal for H-wireline coring to 250m, but also able to use air-flush for rotary air blast (RAB), reverse-circulation (RC) hammer and air-core drilling, as well as conventional mud-rotary drilling."
The Multitec 4000's compact nature with mast lowered also means it can be loaded into a standard ocean freight container providing a simple transport solution when the rig needs to be moved large distances to a new site.
In swamps and wetlands, ARDCO's amphibious unit can be the solution to haul water, fuel and equipment safely and dryly to the drill site.
When drilling on undeveloped, remote sites, reducing environmental impact and resource use is also a major concern.
Fordia, a Canadian global provider of drilling solutions, has many customers that operate in remote areas with limited water resources and environmental regulations that must be respected.
One such customer had a remote drill site in Mexico, where tanker trucks were used to haul the water to the drill rigs, representing a substantial operational cost.
Fordia suggested they use Eddy, a water-treatment system that would limit water consumption by filtering and re-using the drill water.
Eddy's primary function is to separate drill cuttings from water. Once the drill cuttings are isolated, they can be disposed of in environmentally approved ways.
The water is treated, cleaned and then reused, meaning that a minimal amount of additional water is required.
Contrary to the previously used method of letting the drill bits settle before reusing parts of the drilling water, the water filtered by Eddy is free of drill bits and thus causes less wear and tear on equipment
Dani Knezevic, of Fordia, explains: "Reusing the water filtered by Eddy meant that the drill-bit face was cooled and flushed properly and production increased. Moreover, it allowed the customer to lower its consumption of a scarce resource and to honour their commitment to respect the environment."