Dewatering is the process of moving water from an aquifer by pumping water out of a well or by vertical and horizontal drains. Boart Longyear has drilled numerous dewatering wells globally in alluvial, overburden, and hard rock formations with multiple size completions, helping maintain stability in open pit or underground mines. Boart Longyear offers various size rigs with capabilities to drill wells up to 60 inches (152.4 cm) in diameter and depths over 8,000 feet (2438 meters).
Potable wells provide water safe enough to be consumed by humans, such as water supplied to households, commerce, and industry. Boart Longyear has extensive experience drilling potable water wells for both municipalities and private water corporations. The drilled wells are larger completions, between 12–18 inches (30.5 – 45.7 cm) and depths over 3,000 feet (914 meters).
Sometimes referred to as “service holes,” paste holes are drilled and cased at underground mines. The cased holes are then used to supply utilities, aggregate, cement, air shafts, etc. to the underground mine.
Injection wells are vertically drilled to pump water, other liquids, or gases into specific geological formations. Boart Longyear is involved in drilling injection wells in order to relocate water from one aquifer to another, as well as for CO2 injection research. These wells can be large or small diameter, with depths of up to 8,000 feet (2438.4 meters).
Angle wells are drilled at an angle to reach a target that would otherwise not be obtainable. Typically, angle wells are drilled directionally. Boart Longyear uses a unique bottom hole assembly to drill angle water wells in order to achieve the desired target. Usually the technique is used for smaller diameter completion wells, but depending on ground conditions, it can also be used for large completion wells. Angle wells are not only used to hit a specific target, but also gives the ability to drill through multiple vertical water-bearing fractures that if drilled vertically often produces less gallons per minute.
Often, pockets of water are near the walls of a pit, creating pressure and making it unstable. Boart Longyear effectively relieves wall pressure by drilling horizontal holes in the wall, creating an outlet for water to drain.
Directional drilling is the process of drilling nonvertical wells in order to hit a specific target. This process uses a mud motor to rotate the bit with a unique bottom hole assembly, allowing the string to be steered to reach the desired target. These holes are usually drilled with conventional mud, but also can be drilled with conventional air 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, methane vent wells, pre-collar for raise bores, water wells, and sometimes 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)|
Dual Tube Flooded Reverse
Dual Tube Flooded Reverse (DTFR) – This drilling process uses dual wall drill pipe and drilling fluid along with the injection of air in order to drill large diameter holes. In the drill sting, perforations allow the air to return up the center, following the path of least resistance. The air traveling back up the inner tube creates a vacuum, which in turn sucks up the cuttings from the bottom of the hole at the face of the bit. In the DTFR system, fluids always circulate inside the dual tube pipe and can’t escape into the formations. Instead of maintaining fluids at the surface and circulating throughout the wellbore, the DTFR system will generally drill with the borehole fluids at their naturally occurring level. Boart Longyear uses the DTFR system to effectively drill large diameter water wells around the globe.
Direct air rotary drilling forces compressed air down the drill string and through holes in the bit. The compressed air collects the cuttings and carries them to the surface. This method is often used in softer formations.
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 to 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.
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.
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, the hole is advanced to the desired depth into a competent geological formation and well installation can be accomplished in a controlled environment.
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.