What Are Drilling Muds Used For?

Drilling mud is a term frequently used in the oil and gas industry and refers to any liquid drilling fluid.  This heavy, gelatinous mixture is used predominately during oil drilling and natural gas wells, as well as on exploration drilling rigs. However, drilling fluid can also be used for more basic drilling processes, such as water wells. In this article, learn about drilling mud along with its benefits!

What are the types of drilling muds?

There are 3 main types of liquid drilling fluid, or drilling mud:

• Oil Based Mud
• Water Based Mud
• Gaseous Drilling Fluid

Most of the drilling muds are based on water (fresh or saltwater) or brines (natural or manmade). These drilling muds also contain clay and barite to give it weight and viscosity. Oil based muds however, use products such as diesel or mineral oil. Some synthetic drilling muds use highly refined compounds that can be made according to specific property specifications. 

How does it work?

When drilling, the mud is pumped down the hollow pipe to the drill bit and then is flushed back up the borehole to the surface. If any oil or synthetic based mud is used, it is typically cleaned and recirculated for both economic and environmental reasoning. 

The benefits of drilling muds

Drilling mud is used for a variety of reasons in this industry. Advantages are achieved by the drilling mud combined with hydrostatic pressure. The main reasons include:

• Prevent formation fluids from entering the well bore by providing hydrostatic pressure,
• Helps prevent formation damage, limit any corrosion and stabilize rock,
• Suspends the drill cuttings when drill assembly is being brought in or out as well as when drilling is paused,
• Keeps the drill bit clean, cool and lubricated,
• Can carry drill cuttings out,
• Carries the rock excavated by the drill bit to the surface,
• Maintains well bore stability,
• Transmits hydraulic energy to the drill bits and tools.