When ground conditions are saturated with water and broken, a ring of holes are directionally steered to a specific target around the area to be mined. A loop system is then put in the holes (think refrigeration coils) and nitrogen is pumped into the loop system to freeze the ground. Once the ground is frozen, it is easier to mine out.
Sometimes referred to as “service holes,” paste holes are drilled and cased at underground mines. These cased holes are then used to supply utilities, aggregate, cement, air shafts, and more to the underground mine.
Mineral exploration is the process of drilling holes in the desired ground, using reverse circulation to bring the cuttings to the surface for analysis. Usually these holes range from 5 inches to 6 ¾ inches depending on the depth required and whether the holes are being used for pre-collars for core tails. Boart Longyear has done extensive drilling in mineral exploration with depths up to 5,000 feet.
Water Test Holes/Monitor Wells
Water test holes or monitor wells are a small diameter drill hole used to measure static water level, water quality, and water movement. These drill holes are used to either find substantial water to put in a well field, or to check the ground water for various types of contamination. While drilling these types of holes, Boart Longyear records the rate of penetration, collects samples for the evaluation of fractures, and performs injection tests when required. Boart Longyear has extensive knowledge globally drilling water test holes and monitor wells.
Directional drilling is the process of drilling non-vertical wells to hit a specific target. The directional process uses a mud motor to rotate the bit with a unique bottom hole assembly to allow the string to be steered to hit the desired target. These holes are usually drilled with mud conventional methods but also can be drilled with air conventional methods to power the mud motor and clean the well. Surveys are taken throughout the drilling process to ensure the hole is on target. Boart Longyear uses directional capabilities to drill paste holes and methane vent wells, pre-collar for raise bores and water wells, and sometimes for mineral exploration.
|Rigs||Pull Back||Drillrod Size||Hole Size||Angle Capable|
|DH I (Modified Driltech)||90,000 Lbs.||5.5" & 7"||6 3/4" - 22"||No|
|DH III (Modified Driltech)||90,000 Lbs.||5.5" & 7"||6 3/4" - 22"||No|
|T130XD (Schramm)||130,000 Lbs||5.5" & 7"||6 3/4" - 26"||Yes|
|LR140 (Boart Longyear)||140,000 Lbs||5.5" & 7"||6 3/4" - 38"||Yes|
|T145 (Schramm)||145,000 Lbs||5.5" & 7"||6 3/4" 20"||No|
|LR200 (Boart Longyear)||200,000 Lbs||5.5" & 7"||6 3/4" - 31"||No|
|LR300 (Boart Longyear)||300,000 Lbs.||5.5", 7" & 9 5/8"||6 3/4" - 60"||No|
|LR500 (Boart Longyear)||500,000 Lbs.||6 5/8"||8 3/4" - 60"||No|
|LR700 (Boart Longyear)||700,000 Lbs.||6 5/8"||8 3/4" - 60"||No|
|Dependent on hole size, casing size and casing wall thickness (call for quotes accordingly)|
Mud rotary utilizes drilling fluid (mud) to cool down the drill bit and simultaneously remove cuttings from the bottom of the borehole. Drilling mud can consist of various ingredients, the most common being bentonite and polymers. As the mud returns to the surface, it is collected in a mud tank where the cuttings settle and the mud is reused in the drilling process. This method is commonly used in sand and gravel formations where borehole wall stability is an issue, because the drilling mud helps to stabilize the borehole.
Air Hammer Drilling
Air hammer drilling forces compressed air through the drill pipe to drive an air hammer bit at the bottom of the borehole. The pneumatic bit rapidly strikes the rock, pulverizing it. The entire drill string is simultaneously rotated during drilling to aid in keeping the borehole straight. After the compressed air exits the hammer, cuttings are collected at the surface. This method advances quickly, even in hard formations. Air drilling doesn’t seal off the borehole, which allows for higher producing aquifers than mud rotary.
Dual Rotary maintains borehole stability by advancing an outer casing, which allows advancement in the most challenging ground conditions where other overburden drilling systems are unsuccessful. Once the casing is in place, well installation can be accomplished in a controlled environment.
This method of drilling utilizes a dual tube drill string. Drill fluid or air flows down the inner annulus of the drill string, collects cuttings at the bit face, and travels back up the center of the string. If using fluid instead of air, the fluid is collected on the surface where it is filtered and recirculated in the drilling process.
Safety comes first in all activities. We adhere to all local regulatory safety requirements. We have a responsibility to ourselves, our employees, contractors, customers and shareholders to proactively work on strengthening our safety culture. Boart Longyear strives to ensure that our global base of clients can expect the same quality services at any site. Our people are the very foundation of this success and we are dedicated to hiring and training the best in the industry.
Global EHS Management System
Our Global EHS Management System (GEMS) is a web based system that captures data relating to injuries, motor vehicle incidents, equipment damage, environmental impacts, near misses and other safety related incidents of all employees spread across 40 countries.
Stop Work Authority
Boart Longyear employees are equipped with a "Stop Work Authority Card" that authorizes them to immediately stop any work that does not comply with safety standards. The Stop Work Authority Program ensures that employees will not be punished or reprimanded for doing so.
Golden Rules of Safety
The Golden Rules of Safety are a list of questions to ask while on the job. If the answer to any of the questions is NO, our employees stop and take the necessary corrective action and continue only when the answer is YES.
In 2011, Boart Longyear launched a world-class safety campaign aimed at increasing the safety culture with employees. The THINK program instills in staff to never make any task menial and to always "THINK" before they act.
Rules of the Road
Safe driving is an essential component of the way we do business at Boart Longyear. The Rules of the road are designed to protect our employees, passengers, and the public. Adherence to the rules is a condition of employment.
In-Vehicle Monitoring Program (inthinc)
Boart Longyear uses an in-vehicle monitoring system that provides verbal coaching and weekly reports on driver performance and location. This program has been implemented on four continents with plans for future expansion.