Mud rotary drilling is adaptable for a wide range of trenchless construction situations, and is considered the most versatile and common of drilling methods.
The practice of mud rotary drilling has been around since the late 19th century. The flow of drilling mud is the key to the process. The mud is injected into the drill pipe and flows to the drill bit. Usually made of bentonite clay, drilling mud serves many purposes. It lubricates the equipment, applies pressure and support to the borehole wall, and transports spoil from the excavation back to the surface.
Mud rotary drilling is often the default drilling method for trenchless construction operators. it is effective in most geological environments, whether bedrock, sand, gravel, or broken rock. It provides stability to prevent hole collapse. However, mud rotary drilling may be slower than other methods, such as air rotary drilling or foam drilling. It is generally associated with lower costs and higher production. The mud wall cake formed by the bentonite clay can also prevent the infiltration of dangerous gases.