Grout

Openings or voids can be encountered around the casing during the drilling process. These voids, called annular spaces, need to be filled with a type of cement called grout.

The grout acts as a seal to prevent surface water from following the casing down to the groundwater. It also stabilizes the formation and protects the exterior of the casing from corrosion. For deep wells drilled into water-bearing rock formations, the grout is installed from the surface to the bottom of the casing.