A research study submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Engineering and Technology

Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 1991

In the face of increasing cost of pumping water and limiting available resources, the well spacing analysis provides a guideline to minimize cost of pumping water and effect of well interference. The aquifers treated in this study are non-leaky confined aquifer, leaky confined aquifer and two mutually leaky confined aquifer. The mathematical models have been used for the determination of dimensionless parameters and cost of water production. Coefficient of interference has been calculated by using the principle of superposition. Theis nonequilibrium formula has been used to determine the residual drawdown for n, number of cycles for different values of pumping fraction. The value of drawdown decreases with the increase in storage coefficient of aquifer, time of pumping, leakage factor, recovery period and penetration ratio. But the value of drawdown increases with the increase in number of cycles and hydraulic conductivity ratios. The optimum well spacing increases with the increase in aquifer diffusivity (T/S), and hydraulic conductivity ratio and decreases with the increase in conveyance losses. With the decrease in storage coefficient, the unit cost of water increases for 0.45 and 0.65 value of optimum penetration ratio. The results are presented in the form of graphs between two dimensionless parameters and a numerical example is worked out to illustrate the use of graph.