THREE· DIMENSIONAL STUDY OF STREAMFLOW DEVELOPING AROUND RADIAL WELLS

Abstract

Based on the completed three dimensional electric analogous studies the following main points can be established: 1. In case of a radial well sited in an extensiye horizontal layer: a) the capacity of well is proportional to the 0.87th power of the thickness of the layer, b) the increase of the number of horizontal pipes with the same total length causes just a slight decrease in discharge, therefore, when determining the number of horizontal pipes, they are not the hydraulic aspects which are decisive, c) limiting the perforation just for the outer half length of the horizontal pipe causes about a 5% reduction in discharge only. 2. In case of a radial well sited near a river-bed. the horizontal pipe in the direction opposite to the river-bed can be omitted without any considerable decrease in discharge. 3. The horizontal pipe reaching under the riverbed considerably increases the discharge, but can result in a rapid colmation. 4. Colmation extends the influence of the well on a longer section of the riyer-bed, that is why its effect to decrease the discharge develops relatively slowly. 5. Enlightening the development of physical, chemical and biological colmation is by all means necessary to forecast and delay the "ageing" of wells.