The following factors should be considered when selecting an appropriate drilling method:
Solid-stem augering is most useful in fine-grained, unconsolidated materials that will not collapse when unsupported. The method is similar to hollow-stem, except the augers must be removed from the borehole to allow insertion of the well casing and screen. In situ geologic samples are difficult to collect when using a solid-stem. In many cases, it is necessary to rely on the cuttings, which come to the surface, for geologic sampling. This is an undesirable method because the exact depth at which the cuttings come from is not known.