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.