Modelação computacional de poços, com rede atípica e fatores de ajustes, para um melhor entendimento dos parâmetros envolvidos.

Abstract

This Master's Dissertation is yet another attempt to better understand the hydrodynamics of the Well System, this being an extension of the line of research on this topic, in search of finding a viable solution for the economic exploration of both tubular and Amazonas type wells in unconfmed shallow aquifers of the Semi-Arid Paraiba state. Thus, this study is aimed at obtaining better yields from the Aquifer-Well system, as also to prolong the useful life of the system, by way of computer simulations utilizing discretization of the area of influence by a refined network, principally in the proximity of the wells (both tubular and Amazonas type) under study. Such an approach permits the implementation of certain adjustment factors for a better representation of the behavioral tendencies of the real system through the adoption of the model. The refined network utilized in the ground water flow modeling has its governing equation expressed in the finite volume form. This method was adopted with the object of studying the drawdowns that occur in the proximity of the production well, which in some form or the other, influence the behavior of the well, more so in Large Diameter Amazonas type Wells. Such Large Diameter Wells are of particular interest, as they are of fundamental importance to the small and medium farmers in the rural areas of north-east Brazil. The model is developed in the Pascal Language Version V I , where-in were utilized two programs, one developed for Tubular Shallow Well and the other to simulate the functioning o f the Large Diameter Well. Both these wells were located in the same aquifer in the Municipality of Jerico in Northwest Semi-Arid Paraiba. The results of pumping tests conducted by the State Organ - Mineral Resources Development Company (CDRM) were utilized in this study. The results obtained by way o f simulations effected on both the computer models were quite satisfactory. These are found to be very near the field observations and therefore were extended further to other situations which were described in the dissertation. The adjustment factors that were necessary to calibrate the draw-down curve, from a point far away at the radius of influence till sections very near the production well, served excellently to show the reality. These factors can safely be used to extrapolate the diameters of wells, discharges and drawdowns so that the agriculturist may adopt the right type of well under a given soil condition of the aquifer to obtain the optimum yield from the aquifer under study.