The use of a drilling expander for taking additional samples from a drilled well during the exploration of placer deposits of the cryolithozone

In this article, we propose a way to replace test pits in the exploration of placer deposits of the cryolithozone. The idea is to take an additional volume of samples from a pre-drilled exploration well by expanding its trunk in a given interval using a specially designed and patented device for local expansion of the borehole section (Patent for Invention No. 2792482 dated November 15, 2022). Thus, by using a drilling expander, it is possible to obtain an additional volume of samples from the well, while the well expansion is performed only in a certain area of the well. If the diameter of the well expansion is 1300 mm or more, then using an expander will allow extracting from a given well interval the same volume of samples that is obtained during the construction of a test pit. This method will make it possible to replace construction of a test pit in the exploration of placer deposits of the cryolithozone, which are characterized by a high proportion of manual labor and require significant financial resources and time.