How to Mix Bentonite for Drilling Mud

Bentonite is indispensible in well drilling.

To drill a water well, you need to start with mud. Mixing dry, powdered bentonite clay with water makes drilling mud. Bentonite increases the viscosity of the water used in the drilling process. Making the drilling fluid thicker allows it to lift soil and rocks out of the well shaft as it is being drilled. This action removes soil from the bottom of the hole and prevents the bit becoming plugged as it sinks further into the ground. It also prevents the sides of the shaft from collapsing during the drilling operation.

Things You'll Need

• Drilling pan
• Fresh water
• Mud-circulating pump

Instructions

1. Place the drilling pan on level ground.

2. Fill the pan with water.

3. Place the pump's circulating hoses in the pan. The end of the intake hose must be completely submerged in the water.

4. Start the circulating pump.

5. Open a bag of bentonite and slowly pour it into the circulating water. Adding the powdered clay too quickly will cause the clay to lump. This reduces the clay's effectiveness and could clog the pump.

6. Continue adding bentonite until the mud reaches the desired viscosity.

7. Allow the circulating pump to mix the clay for at least five minutes before drilling.

Tips & Warnings

• Once drilling begins, use a shovel to frequently check the bottom of the pan and remove soil cuttings, rocks and sand. These will build up and cause the drilling pan to overflow. Sand and rocks can also damage the pump if they are allowed to enter the intake hose.

References

• Michael Mattson; Mattson & Sons Well Drilling; Wolverine, Michigan
• Drillfloor: Drilling Fluid: Mixing in the Correct Order
• Drillfloor: Drilling Fluid: Bentonite