Abstract
Adequate knowledge of the hydraulic characteristics of production wells is indispensable for the proper development and management of wells and for the selection of suitable pumps. In this study, the characteristic hydraulic parameters of production wells were determined by the widely used graphical analysis of step-drawdown pumping test data as well as the two traditional gradient-based nonlinear optimization techniques (viz., Levenberg-Marquardt and Gauss-Newton) and the nontraditional optimization technique, genetic algorithm. Three stand-alone and interactive computer programs were developed to optimize the hydraulic parameters of production wells by these numerical techniques. The efficacy and robustness of the developed computer codes were examined using eleven sets of step-drawdown data from diverse hydrogeologic conditions. The results of this study revealed that all the three numerical techniques yielded superior well parameters with lower values of root-mean-square errors (RMSE) for all the eleven data sets compared to the parameters obtained by the graphical method. The values of the exponent (P) ranged from 1.2 to 6.0, which gave minimum RMSE values. Furthermore, it was found that both the Gauss-Newton and Levenberg-Marquardt techniques are sensitive to the initial guess values of well parameters. It is concluded that both the traditional and nontraditional numerical techniques offer an efficient and reliable tool for the determination of well parameters with a greater accuracy and better insight.
Original language | English (US) |
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Pages (from-to) | 617-630 |
Number of pages | 14 |
Journal | Journal of Hydrologic Engineering |
Volume | 11 |
Issue number | 6 |
DOIs | |
State | Published - Nov 1 2006 |
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Civil and Structural Engineering
- Water Science and Technology
- General Environmental Science