Some issues of re-utilization of casing strings, unused water intake wells (for example, some countries in the south-western sahel)

The article discusses some issues of extraction and reuse of casing strings of unused wells in tropical countries. The results of pilot work are presented to solve the above issue. In particular, the consistency of liquefied clay rocks located in the annulus of wells, which in turn depends on the equipment of the strings with drainage pipes, significantly affects the success of the extraction of casing pipes. Optimum arrangements for small diameter drainage pipes and hole sizes were established. The possibilities of applying the results of these works in other regions with a similar characteristic are indicated.