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Belgrade, 27. Marta 71, tel. +38163207646, balby@bitsyu.net

 

DETERMINING YIELD OF WELLS

WITH HORIZONTAL COLLECTORS

BY THE METHOD OF EQUIVALENT RADIUS

Copyright © 2003 Balby International All rights reserved

Doctor's dissertation by Mr. Dushan Babac Ph.D.Eng,Civ., who awarded the doctor's degree in engineering by Belgrade University in 1978, has the title: "Contribution to solution problems of development of wells with horizontal collectors with retrospection on Ranney Wells at Belgrade source of ground water''.

In introduction of this doctor's dissertation the author said: "Construction of wells with horizontal collectors requires grate investment so every mistake in prediction of their yield during period of ground water development could have as a consequence decrease of economy in production of water. In that way usage of these water-intake systems could be senseless.

Because of that determining development odds of ground water sources via wells with horizontal drains destine two fundamental points:

1. Based on geological and hydro geological exploratory proceeding  necessity is to define a yield of a well ( yield of a well from beginning of development ).

2. Based on mechanical, hydrotechnical and hydro biological exploratory proceeding necessity is to determinate variety of yield of a well, during a period of ground water development, end predict a prevention treatment or party rejection of this appearance.

 

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The effect of main parameters on primordial yield of wells with horizontal collectors, with a condition of negligible minor resistance along collectors, is determined  by pilot explorations with electrical analogy appliance. Besides the author used many references about development of wells with horizontal collectors at Belgrade source of ground water and he defined procedure for defining equivalent radius. According to this procedure, streaming toward a well with horizontal collectors add up on streaming toward a vertical well by appropriate radius.

Explorations end formulas are imported  for next conditions:

Distance from a well to a river (b/L)    2= b/L= 10

Thickness of a aquifer (H/L)     0.4= H/L= 1.2

Hydraulic radius in regard to length of collectors     0.1= Re/L= 0.7

Number of collectors     2= n=<8

Analyzed dependence (Re/L)= f (n, H/L) is defined at the next monograph

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The comparison of formula results by several authors: Wagenstein, Nering, Citrini, Glibov - Jotov - Mollov - Petrov - Spasov, Hantush - Papadopulos, Babac is represented at  the picture below:

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The diagram with all details of comparison is located here 119 kB

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The software, by professor Dusan Babac's method, for determining yield of wells

with horizontal collectors annexed in addition:

                                    Bunar-usam-e.gif (3267 bytes)                Bunar-grupa-e.gif (3780 bytes)

Copyright © 2003 Balby International All rights reserved

*** ONE WELL ***     *** GROUP OF WELLS ***