Annular Filler

What Does Annular Filler Mean?

Annular filler is animpervious,usually bentonite, cement or a bentonite-and cement mixplaced in the annulus(the space between thecasing and the borehole wall)to prevent the introduction of drilling fluids or other contaminants fromdrillingoperations into local groundwater sources.

The use of annular filler is mandated by the US Environmental Protection Agency, which also specifies the type of materials to be used, the makeup of the materials used for annular filler and the depth to which the annular filler must be placed.

Annular filler is also known as an annular seal.

Trenchlesspedia Explains Annular Filler

The process of putting filler into the drilling annulus is called "grouting a well." Proper grouting not only prevents groundwater pollution, it's an important safety factor as well.

一些州,如威斯康辛州有一个要求for the use of an annular filler; however, their requirements may not be as strict as those imposed by the US EPA. The EPA requires that annular filler (or annulus filler) consist of 90-percent bentonite, "neat" cement (cement without inclusions, such as gravel) or an unspecified mix of bentonite and cement.