If you're new to the world of borehole drilling, the terminology can feel like a foreign language. From aquifers to casings, there's a lot to learn.
This glossary is designed to help you understand the most common terms and demystify the process.
Aquifer: This is the core of any water well project. An aquifer is a layer of saturated rock, gravel, or sand that can hold and yield a significant amount of water to a well or spring. Think of it as a natural underground reservoir.
Borehole: Simply put, a borehole is the cylindrical hole that is drilled into the ground. It's the physical shaft that allows access to the aquifer below.
Casing: This is a steel or PVC pipe that is placed inside the borehole. Its primary purpose is to keep the hole from collapsing and to prevent surface water contaminants from getting into the well.
Annular Space (or Annulus): This is the empty space between the outside of the casing and the wall of the borehole. It's often filled with cement or a special clay called bentonite to create a seal that further protects the well from contamination.
Static Water Level (SWL): This is the natural water level in the well when the pump is turned off. It's a key measurement that tells you how deep the water table is.
Pumping Water Level (PWL): This is the depth of the water in the well when the pump is actively running. It is always deeper than the static water level.
Drawdown: This is the difference between the static water level and the pumping water level. It tells you how much the water level drops when you are drawing water from the well.
Drill Rig: This is the large piece of machinery used to drill the borehole. There are various types, but their function is to create the hole and install the casing and other components.
Well Screen: A section of the casing that is perforated or slotted. It allows water from the aquifer to enter the well while keeping sand and other unwanted materials out.
Gravel Pack: This is a layer of gravel or coarse sand that is placed in the annular space around the well screen. It acts as a filter, preventing fine particles from entering the well and helping to stabilize the formation around the screen.
Blowout Preventer (BOP): A critical safety device installed at the top of a well. Its purpose is to prevent an uncontrolled release of pressure, such as an influx of gas or fluid from the formation.
Hydrogeology: The scientific study of the distribution and movement of groundwater in the soil and rocks of the Earth's crust. A hydrogeologist is the professional who can help you locate and assess potential water sources for a well.